From mccorkle at ptialaska.net  Wed Oct  1 18:30:20 2008
From: mccorkle at ptialaska.net (Richard H McCorkle)
Date: Wed, 1 Oct 2008 14:30:20 -0800 (AKDT)
Subject: [time-nuts] Piezo Company OXCO pinouts (William Rice)
Message-ID: <21972.206.174.39.163.1222900220.squirrel@mymail.acsalaska.net>

Hi Steve,

Not knowing the rated voltage of the unit I took the overly cautious
approach of slowly increasing the supply voltage until the frequency
first stabilized when varying the voltage over a small range. The unit
stabilized at approximately 10.8v (12v - 10%) so I specified 12v as
the lower limit of the input voltage required. The internal regulator
will run cooler and the oven will draw more current and take longer
to stabilize at the low end of the usable voltage range.
  I didn't test for the maximum voltage as this could turn into a
destructive test if not done properly. I would suspect the internal
regulator can handle input voltages greater than 26.4v (24v + 10%)
safely so the unit could be specified at 24v +/- 10% in the Lucent
application it was designed for. The higher voltage would speed oven
response to changing temperature and reduce the warm-up time.

Regards,
Richard


> Hi Richard,
>
> Many thanks for the info, this was most helpful and I have the unit
> running fine now. The only real difference is that my unit seems to be
> labelled to run off 24V and the data sheet shows 12V. My serial number
> is 2331 (9439) which is not listed on the pdf you sent. After the
> initial panic over running it off 24V for some hours to test it, I
> have tried it on 12V and it still seems to work fine. The difference
> is that the frequency has dropped about .5ppm and the case feels
> cooler to the touch. Now I don't know what the power voltage should be
> as someone else on the list mentioned the nominal is 25.5V. Let's have
> a vote :)
>
> Thanks for your help.
>
> Regards,
> Steve
>
> 2008/9/30 Richard H McCorkle <mccorkle at ptialaska.net>:
>> Hello,
>>
>> I purchased three Piezo 2920136 units and the attached file documents
>> what the pinouts and EFC requirements are. Hope you find this useful.
>>
>> Richard
>>
>>
>>> Just new to this list and found this post while trawling the net for
>>> the same info. This is a manual reply to a previous posting so the
>>> message ids won't tally, sorry.
>>>
>>> --- William Rice wrote:-
>>>> Have a surplus Piezo Crystal Co. oscillator. 3x2x2" with 6 pins on bottom, no
>>>> RF
>>>> connector.
>>>> Model# 2920136 / 10.000 Mhz (101728-001)
>>>> Had trouble finding info.... Maybe standard configuration, 9337 stamped on
>>>> unit,
>>>> probably just obsolete.
>>>> Any help appreciated.
>>>> Did find one on ebay, my unit is not as abused.
>>>> Do not know if it needs external control.
>>>
>>>> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=160286114515
>>>
>>> I have a Piezo Model 2920136 10MHz oscillator which seems to be the
>>> same as in your url link above. The info I have to date for the six
>>> pins from left to right:-
>>>
>>> Out, GND, +24V, ?, Vcc, GND
>>>
>>> I don't know what the 4th (?) pin does and I also have know idea as to
>>> what voltage needs to be connected to the Vcc pin. Any help please?
>>>
>>> Thanks,
>>> Steve
>>> --
>>> Steve Rooke - ZL3TUV & G8KVD
>>> Omnium finis imminet
>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>
>
>
> --
> Steve Rooke - ZL3TUV & G8KVD
> Omnium finis imminet
>






From sar10538 at gmail.com  Wed Oct  1 19:47:34 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Thu, 2 Oct 2008 12:47:34 +1300
Subject: [time-nuts] Piezo Company OXCO pinouts (William Rice)
In-Reply-To: <21972.206.174.39.163.1222900220.squirrel@mymail.acsalaska.net>
References: <21972.206.174.39.163.1222900220.squirrel@mymail.acsalaska.net>
Message-ID: <1231b6a80810011647q20ff3f53n6b4cd13df5215d60@mail.gmail.com>

Hi Richard,

It is always wise to be cautious when dealing with an expensive item
that could easily be fried by too much voltage and I think you took
the correct approach. I found that my oxco seemed to work fine at 12V
but, as it has been pointed out, it would probably take a lot longer
to reach working temperature and may not be able to maintain that in a
cold environment. I've been running mine at 24V for well over a day
now and it seems to be working fine so I guess it's OK to keep it on
that supply. I guess the case on my unit was slightly hotter under 24V
due to the power supply dissipation and I wonder what bearing that
makes to the overall heating of the oven. I will try to see if I can
get some proper test results of the case temperature than my touch
test.

2008/10/2 Richard H McCorkle <mccorkle at ptialaska.net>:
> Hi Steve,
>
> Not knowing the rated voltage of the unit I took the overly cautious
> approach of slowly increasing the supply voltage until the frequency
> first stabilized when varying the voltage over a small range. The unit
> stabilized at approximately 10.8v (12v - 10%) so I specified 12v as
> the lower limit of the input voltage required. The internal regulator
> will run cooler and the oven will draw more current and take longer
> to stabilize at the low end of the usable voltage range.
>  I didn't test for the maximum voltage as this could turn into a
> destructive test if not done properly. I would suspect the internal
> regulator can handle input voltages greater than 26.4v (24v + 10%)
> safely so the unit could be specified at 24v +/- 10% in the Lucent
> application it was designed for. The higher voltage would speed oven
> response to changing temperature and reduce the warm-up time.
>
> Regards,
> Richard
>
>
>> Hi Richard,
>>
>> Many thanks for the info, this was most helpful and I have the unit
>> running fine now. The only real difference is that my unit seems to be
>> labelled to run off 24V and the data sheet shows 12V. My serial number
>> is 2331 (9439) which is not listed on the pdf you sent. After the
>> initial panic over running it off 24V for some hours to test it, I
>> have tried it on 12V and it still seems to work fine. The difference
>> is that the frequency has dropped about .5ppm and the case feels
>> cooler to the touch. Now I don't know what the power voltage should be
>> as someone else on the list mentioned the nominal is 25.5V. Let's have
>> a vote :)
>>
>> Thanks for your help.
>>
>> Regards,
>> Steve
>>
>> 2008/9/30 Richard H McCorkle <mccorkle at ptialaska.net>:
>>> Hello,
>>>
>>> I purchased three Piezo 2920136 units and the attached file documents
>>> what the pinouts and EFC requirements are. Hope you find this useful.
>>>
>>> Richard
>>>
>>>
>>>> Just new to this list and found this post while trawling the net for
>>>> the same info. This is a manual reply to a previous posting so the
>>>> message ids won't tally, sorry.
>>>>
>>>> --- William Rice wrote:-
>>>>> Have a surplus Piezo Crystal Co. oscillator. 3x2x2" with 6 pins on bottom, no
>>>>> RF
>>>>> connector.
>>>>> Model# 2920136 / 10.000 Mhz (101728-001)
>>>>> Had trouble finding info.... Maybe standard configuration, 9337 stamped on
>>>>> unit,
>>>>> probably just obsolete.
>>>>> Any help appreciated.
>>>>> Did find one on ebay, my unit is not as abused.
>>>>> Do not know if it needs external control.
>>>>
>>>>> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=160286114515
>>>>
>>>> I have a Piezo Model 2920136 10MHz oscillator which seems to be the
>>>> same as in your url link above. The info I have to date for the six
>>>> pins from left to right:-
>>>>
>>>> Out, GND, +24V, ?, Vcc, GND
>>>>
>>>> I don't know what the 4th (?) pin does and I also have know idea as to
>>>> what voltage needs to be connected to the Vcc pin. Any help please?
>>>>
>>>> Thanks,
>>>> Steve
>>>> --
>>>> Steve Rooke - ZL3TUV & G8KVD
>>>> Omnium finis imminet
>>>>
>>>> _______________________________________________
>>>> time-nuts mailing list -- time-nuts at febo.com
>>>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>>> and follow the instructions there.
>>>>
>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>>
>>
>>
>>
>> --
>> Steve Rooke - ZL3TUV & G8KVD
>> Omnium finis imminet
>>
>
>
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>



-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From sar10538 at gmail.com  Wed Oct  1 20:07:48 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Thu, 2 Oct 2008 13:07:48 +1300
Subject: [time-nuts] Testing frequency using NTP
Message-ID: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>

I'm wondering about the possibility of checking the frequency of my
oscillator by using a NTP synced RT Linux system. What I'm thinking of
doing is building a long chain of dividers feeding a standard freq
counter in totallise mode such that I can count the number of cycled
over a long time period. What I would then do is to gate this with the
Linux system to measure the number of cycles over that period. I
figure that although the exact point of gate switching would not be
very accurate, due to clock jitter and uncertain delays in the OS,
this error could be made insignificant, in terms of the possible
stability of the oxco, when the sampling period is large. Even
watching the NTP stats on my workstation, OpenSUSE 11, it seems to
remain stable within a few ms, now that it has been stabilised for
months, and on a dedicated real time Linux system I should be able to
switch the gate within ms of the correct time so these errors should
only affect the least significant bits of the counting chain. If I
make the sampling period long, say hours, this should push those
errors well down the ppm.

Anyone have comments on this approach please? Feel free to blow holes in it.

Thanks,
Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From bruce.griffiths at xtra.co.nz  Wed Oct  1 20:44:48 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Thu, 02 Oct 2008 13:44:48 +1300
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>
References: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>
Message-ID: <48E41980.5050809@xtra.co.nz>

Steve Rooke wrote:
> I'm wondering about the possibility of checking the frequency of my
> oscillator by using a NTP synced RT Linux system. What I'm thinking of
> doing is building a long chain of dividers feeding a standard freq
> counter in totallise mode such that I can count the number of cycled
> over a long time period. What I would then do is to gate this with the
> Linux system to measure the number of cycles over that period. I
> figure that although the exact point of gate switching would not be
> very accurate, due to clock jitter and uncertain delays in the OS,
> this error could be made insignificant, in terms of the possible
> stability of the oxco, when the sampling period is large. Even
> watching the NTP stats on my workstation, OpenSUSE 11, it seems to
> remain stable within a few ms, now that it has been stabilised for
> months, and on a dedicated real time Linux system I should be able to
> switch the gate within ms of the correct time so these errors should
> only affect the least significant bits of the counting chain. If I
> make the sampling period long, say hours, this should push those
> errors well down the ppm.
>
> Anyone have comments on this approach please? Feel free to blow holes in it.
>
> Thanks,
> Steve
>   
Steve

Save yourself a counter and just divide the frequency down to about 1Hz 
and time stamp the 1Hz transitions with the Linux box.
As long as you know the division factor its easy enough to calculate the 
frequency.

Bruce



From scmcgrath at gmail.com  Wed Oct  1 20:48:28 2008
From: scmcgrath at gmail.com (Scott McGrath)
Date: Wed, 1 Oct 2008 20:48:28 -0400
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>
References: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>
Message-ID: <c9ffea950810011748na42dcbbrb95041c13c608a6a@mail.gmail.com>

It depends on how accurately you want to measure the oscillator
frequency with your approach short term you probably would not be able
to measure the oscillator offset any better than a few parts in 10-5
longer term probably a few parts in 10-7 might be possible as you
could compute the allen deviation and fit a curve through the median
values.

NTP from a stratum 3 clock is only going to be precise to a few
milliseconds and for meaningful accuracy you need another order of
magnitude.   This is part of the function of the drift file in xntpd
in which the daemon attempts to compensate for the drift and offset
inherent in cheap oscillators used in computer applications.


- Fellow nuts am I all wet here or have I missed a technique

On Wed, Oct 1, 2008 at 8:07 PM, Steve Rooke <sar10538 at gmail.com> wrote:
> I'm wondering about the possibility of checking the frequency of my
> oscillator by using a NTP synced RT Linux system. What I'm thinking of
> doing is building a long chain of dividers feeding a standard freq
> counter in totallise mode such that I can count the number of cycled
> over a long time period. What I would then do is to gate this with the
> Linux system to measure the number of cycles over that period. I
> figure that although the exact point of gate switching would not be
> very accurate, due to clock jitter and uncertain delays in the OS,
> this error could be made insignificant, in terms of the possible
> stability of the oxco, when the sampling period is large. Even
> watching the NTP stats on my workstation, OpenSUSE 11, it seems to
> remain stable within a few ms, now that it has been stabilised for
> months, and on a dedicated real time Linux system I should be able to
> switch the gate within ms of the correct time so these errors should
> only affect the least significant bits of the counting chain. If I
> make the sampling period long, say hours, this should push those
> errors well down the ppm.
>
> Anyone have comments on this approach please? Feel free to blow holes in it.
>
> Thanks,
> Steve
> --
> Steve Rooke - ZL3TUV & G8KVD
> Omnium finis imminet
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>


From jim77742 at gmail.com  Wed Oct  1 20:55:15 2008
From: jim77742 at gmail.com (Jim Palfreyman)
Date: Thu, 2 Oct 2008 10:55:15 +1000
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: <c9ffea950810011748na42dcbbrb95041c13c608a6a@mail.gmail.com>
References: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>
	<c9ffea950810011748na42dcbbrb95041c13c608a6a@mail.gmail.com>
Message-ID: <f616e0f80810011755s1bc63d12g2d31e3975469507f@mail.gmail.com>

But wouldn't, over time, all this ntp/OS/network "noise" average away
because ultimately the whole system is being locked to an atomic clock? I
know any given measurement will have errors in the order of milliseconds,
but the long term average ought to be good. Ought it?

You could test it by giving the linux box the 1PPS from a Thunderbolt
(instead of your OCXO) and seeing what the results are with time.

But I suppose you don't have one of those otherwise you'd use it to measure
your OCXO...

Jim


2008/10/2 Scott McGrath <scmcgrath at gmail.com>

> It depends on how accurately you want to measure the oscillator
> frequency with your approach short term you probably would not be able
> to measure the oscillator offset any better than a few parts in 10-5
> longer term probably a few parts in 10-7 might be possible as you
> could compute the allen deviation and fit a curve through the median
> values.
>
> NTP from a stratum 3 clock is only going to be precise to a few
> milliseconds and for meaningful accuracy you need another order of
> magnitude.   This is part of the function of the drift file in xntpd
> in which the daemon attempts to compensate for the drift and offset
> inherent in cheap oscillators used in computer applications.
>
>
> - Fellow nuts am I all wet here or have I missed a technique
>
> On Wed, Oct 1, 2008 at 8:07 PM, Steve Rooke <sar10538 at gmail.com> wrote:
> > I'm wondering about the possibility of checking the frequency of my
> > oscillator by using a NTP synced RT Linux system. What I'm thinking of
> > doing is building a long chain of dividers feeding a standard freq
> > counter in totallise mode such that I can count the number of cycled
> > over a long time period. What I would then do is to gate this with the
> > Linux system to measure the number of cycles over that period. I
> > figure that although the exact point of gate switching would not be
> > very accurate, due to clock jitter and uncertain delays in the OS,
> > this error could be made insignificant, in terms of the possible
> > stability of the oxco, when the sampling period is large. Even
> > watching the NTP stats on my workstation, OpenSUSE 11, it seems to
> > remain stable within a few ms, now that it has been stabilised for
> > months, and on a dedicated real time Linux system I should be able to
> > switch the gate within ms of the correct time so these errors should
> > only affect the least significant bits of the counting chain. If I
> > make the sampling period long, say hours, this should push those
> > errors well down the ppm.
> >
> > Anyone have comments on this approach please? Feel free to blow holes in
> it.
> >
> > Thanks,
> > Steve
> > --
> > Steve Rooke - ZL3TUV & G8KVD
> > Omnium finis imminet
> >
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at febo.com
> > To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
> >
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

From bg at lysator.liu.se  Thu Oct  2 00:50:48 2008
From: bg at lysator.liu.se (=?ISO-8859-1?Q?Bj=F6rn?= Gabrielsson)
Date: Thu, 02 Oct 2008 06:50:48 +0200
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: <c9ffea950810011748na42dcbbrb95041c13c608a6a@mail.gmail.com>
References: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>
	<c9ffea950810011748na42dcbbrb95041c13c608a6a@mail.gmail.com>
Message-ID: <1222923048.2558.6.camel@bg-desktop>


On Wed, 2008-10-01 at 20:48 -0400, Scott McGrath wrote:
> It depends on how accurately you want to measure the oscillator
> frequency with your approach short term you probably would not be able
> to measure the oscillator offset any better than a few parts in 10-5
> longer term probably a few parts in 10-7 might be possible as you
> could compute the allen deviation and fit a curve through the median
> values.
> 
> NTP from a stratum 3 clock is only going to be precise to a few
> milliseconds and for meaningful accuracy you need another order of
> magnitude.   This is part of the function of the drift file in xntpd
> in which the daemon attempts to compensate for the drift and offset
> inherent in cheap oscillators used in computer applications.
> 

You do not have to chose a bad NTP server. With better servers you can
gain a few orders of magnitude. 

$ ntpq -p timehost.lysator.liu.se

     remote           refid      st ...  delay   offset  jitter
================================================================
*GENERIC(0)      .GPS.            0 ...   0.000    0.014   0.002
+nissan.ifm.liu. .PPS.            1 ...   0.651    0.000   0.035
+ntp1.sth.netnod .PPS.            1 ...   3.667   -0.018   0.052
+ntp2.gbg.netnod .PPS.            1 ...  10.967   -0.010   0.014
-ntp1.mmo.netnod .PPS.            1 ...  13.899   -0.077   0.061

Also look at the NTP temperature compensation discussion at

    http://www.ijs.si/time/temp-compensation/


--

    Bj?rn



From sar10538 at gmail.com  Thu Oct  2 01:18:04 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Thu, 2 Oct 2008 18:18:04 +1300
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: <48E41980.5050809@xtra.co.nz>
References: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>
	<48E41980.5050809@xtra.co.nz>
Message-ID: <1231b6a80810012218t8f9b37y7395215c24229305@mail.gmail.com>

2008/10/2 Bruce Griffiths <bruce.griffiths at xtra.co.nz>:

> Save yourself a counter and just divide the frequency down to about 1Hz
> and time stamp the 1Hz transitions with the Linux box.
> As long as you know the division factor its easy enough to calculate the
> frequency.

I'd planned on a simple interface to the PC via using the parallel,
suitably strapped, as a basic output port. Now, I could use it as an
input but I'd probably have to poll the port which would be somewhat
inefficient but an option I guess. Think I could just record the
staring time of the sampling and then the ending time plus the number
of cycles.

Cheers,
Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From sar10538 at gmail.com  Thu Oct  2 01:37:08 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Thu, 2 Oct 2008 18:37:08 +1300
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: <c9ffea950810011748na42dcbbrb95041c13c608a6a@mail.gmail.com>
References: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>
	<c9ffea950810011748na42dcbbrb95041c13c608a6a@mail.gmail.com>
Message-ID: <1231b6a80810012237y11625d66h986df3b5987ac8ec@mail.gmail.com>

Hmmm... If I measured a 10MHz oscillator for a 1/10 second, I could
achieve, at best, 1ppm accuracy. Now my measuring system has a non
accumulating error in the ms range, say <1s, so this would be totally
unworkable. If I sampled for 1s, best would be .1ppm accuracy, but my
measuring errors would still swamp the result. To make my measuring
errors small, I could make the 1s overhead very small compared to the
measing time period by, say, sampling for 10^6s thereby making the 1s
error 1ppm. Now the 1s error is probably considerably smaller than
that, probably by the order of at least a decade or two. If it was
just .1s error, I could get a result to 1ppm in about a day and better
if I sample of a number of days.

Cheers,
Steve

2008/10/2 Scott McGrath <scmcgrath at gmail.com>:
> It depends on how accurately you want to measure the oscillator
> frequency with your approach short term you probably would not be able
> to measure the oscillator offset any better than a few parts in 10-5
> longer term probably a few parts in 10-7 might be possible as you
> could compute the allen deviation and fit a curve through the median
> values.
>
> NTP from a stratum 3 clock is only going to be precise to a few
> milliseconds and for meaningful accuracy you need another order of
> magnitude.   This is part of the function of the drift file in xntpd
> in which the daemon attempts to compensate for the drift and offset
> inherent in cheap oscillators used in computer applications.
>
>
> - Fellow nuts am I all wet here or have I missed a technique

-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From sar10538 at gmail.com  Thu Oct  2 01:39:40 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Thu, 2 Oct 2008 18:39:40 +1300
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: <f616e0f80810011755s1bc63d12g2d31e3975469507f@mail.gmail.com>
References: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>
	<c9ffea950810011748na42dcbbrb95041c13c608a6a@mail.gmail.com>
	<f616e0f80810011755s1bc63d12g2d31e3975469507f@mail.gmail.com>
Message-ID: <1231b6a80810012239h2fe73a5eh3d123679c78af647@mail.gmail.com>

Hi Jim,

That's exactly what I was thinking too. Indeed, if I had a decent freq
std I'd use that to measure my oxco. Guess I'm just bouncing ideas
around here and looking for any input.

Cheers,
Steve

2008/10/2 Jim Palfreyman <jim77742 at gmail.com>:
> But wouldn't, over time, all this ntp/OS/network "noise" average away
> because ultimately the whole system is being locked to an atomic clock? I
> know any given measurement will have errors in the order of milliseconds,
> but the long term average ought to be good. Ought it?
>
> You could test it by giving the linux box the 1PPS from a Thunderbolt
> (instead of your OCXO) and seeing what the results are with time.
>
> But I suppose you don't have one of those otherwise you'd use it to measure
> your OCXO...
>
> Jim
>
>
> 2008/10/2 Scott McGrath <scmcgrath at gmail.com>
>
>> It depends on how accurately you want to measure the oscillator
>> frequency with your approach short term you probably would not be able
>> to measure the oscillator offset any better than a few parts in 10-5
>> longer term probably a few parts in 10-7 might be possible as you
>> could compute the allen deviation and fit a curve through the median
>> values.
>>
>> NTP from a stratum 3 clock is only going to be precise to a few
>> milliseconds and for meaningful accuracy you need another order of
>> magnitude.   This is part of the function of the drift file in xntpd
>> in which the daemon attempts to compensate for the drift and offset
>> inherent in cheap oscillators used in computer applications.
>>
>>
>> - Fellow nuts am I all wet here or have I missed a technique
>>
>> On Wed, Oct 1, 2008 at 8:07 PM, Steve Rooke <sar10538 at gmail.com> wrote:
>> > I'm wondering about the possibility of checking the frequency of my
>> > oscillator by using a NTP synced RT Linux system. What I'm thinking of
>> > doing is building a long chain of dividers feeding a standard freq
>> > counter in totallise mode such that I can count the number of cycled
>> > over a long time period. What I would then do is to gate this with the
>> > Linux system to measure the number of cycles over that period. I
>> > figure that although the exact point of gate switching would not be
>> > very accurate, due to clock jitter and uncertain delays in the OS,
>> > this error could be made insignificant, in terms of the possible
>> > stability of the oxco, when the sampling period is large. Even
>> > watching the NTP stats on my workstation, OpenSUSE 11, it seems to
>> > remain stable within a few ms, now that it has been stabilised for
>> > months, and on a dedicated real time Linux system I should be able to
>> > switch the gate within ms of the correct time so these errors should
>> > only affect the least significant bits of the counting chain. If I
>> > make the sampling period long, say hours, this should push those
>> > errors well down the ppm.
>> >
>> > Anyone have comments on this approach please? Feel free to blow holes in
>> it.
>> >
>> > Thanks,
>> > Steve
>> > --
>> > Steve Rooke - ZL3TUV & G8KVD
>> > Omnium finis imminet
>> >
>> > _______________________________________________
>> > time-nuts mailing list -- time-nuts at febo.com
>> > To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> > and follow the instructions there.
>> >
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>



-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From sar10538 at gmail.com  Thu Oct  2 01:49:28 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Thu, 2 Oct 2008 18:49:28 +1300
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: <1222923048.2558.6.camel@bg-desktop>
References: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>
	<c9ffea950810011748na42dcbbrb95041c13c608a6a@mail.gmail.com>
	<1222923048.2558.6.camel@bg-desktop>
Message-ID: <1231b6a80810012249p17db7cect1bc1e698e870f57@mail.gmail.com>

Your results are considerably better than mine but these are just off
my busy workstation taken as a snapshot. I have no local time standard
so dependant on the external servers. Perhaps I could do better on a
dedicated system running a RT Linux:-

ntpdc> peers
     remote           local      st poll reach  delay   offset    disp
=======================================================================
=LOCAL(0)        127.0.0.1       10   64  377 0.00000  0.000000 0.03079
=infinite-loop.n 192.168.0.2      2 1024  377 0.08951  0.010470 0.13661
*gen2.ihug.co.nz 192.168.0.2      2 1024  377 0.06548  0.008092 0.13657
=mu-relay2.masse 192.168.0.2      2 1024  377 0.10503  0.003384 0.13667
=ns2.compass.net 192.168.0.2      2 1024  377 0.06645 -0.007766 0.12173
ntpdc>

Over a long sampling time though, these errors should factor out to be
very small anyway.

Cheers,
Steve

2008/10/2 Bj?rn Gabrielsson <bg at lysator.liu.se>:
> You do not have to chose a bad NTP server. With better servers you can
> gain a few orders of magnitude.
>
> $ ntpq -p timehost.lysator.liu.se
>
>     remote           refid      st ...  delay   offset  jitter
> ================================================================
> *GENERIC(0)      .GPS.            0 ...   0.000    0.014   0.002
> +nissan.ifm.liu. .PPS.            1 ...   0.651    0.000   0.035
> +ntp1.sth.netnod .PPS.            1 ...   3.667   -0.018   0.052
> +ntp2.gbg.netnod .PPS.            1 ...  10.967   -0.010   0.014
> -ntp1.mmo.netnod .PPS.            1 ...  13.899   -0.077   0.061
>
> Also look at the NTP temperature compensation discussion at
>
>    http://www.ijs.si/time/temp-compensation/
>
>
> --
>
>    Bj?rn
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.



-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From brice at weaponeer.com  Thu Oct  2 01:56:43 2008
From: brice at weaponeer.com (brice at weaponeer.com)
Date: Thu, 02 Oct 2008 05:56:43 +0000
Subject: [time-nuts] Piezo Company OXCO pinouts/ Cheap clocks! (William
	Rice)
Message-ID: <W248033494248511222927003@webmail40>

 Thanks for all of the info, I do apologize, my posts/responses always seem to be somewhat off of the norm refering to the standards of Timenuts text.
I have not had a chance to test my Piezo Oscillator, Maybe tomorrow. I have delt with many HP 10833a surplus oscillators from 5328A counters etc.
I have had good luck with those units. I have bought several Trak IRIG units that work perfectly for a week or so, then catch on fire and burn out in a smoking blaze of glory. I am more concerned for the need of the fire department rather than some sort of patriotic statement.
What is the best bang for the buck? Maybe I am just on a bad streak. Have plenty of good test equipmentthat is accurate and healthy.
I am still looking for a HP 2509a Manual. I have one that has been running for about 3 years and 2 that need minor repair. 
I have plenty of RF stuff and can probably make any connections. I just do not have a college engineering background, but understand many RF basics.
I have other assorted FAA and other clocks that work or may need obsolete parts. (Quartz)
Thanks for any help, Bill

-----Original Message-----
From: time-nuts-request at febo.com [mailto:time-nuts-request at febo.com]
Sent: Wednesday, October 1, 2008 11:51 PM
To: time-nuts at febo.com
Subject: time-nuts Digest, Vol 51, Issue 1



From phk at phk.freebsd.dk  Thu Oct  2 03:02:31 2008
From: phk at phk.freebsd.dk (Poul-Henning Kamp)
Date: Thu, 02 Oct 2008 07:02:31 +0000
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: Your message of "Thu, 02 Oct 2008 18:18:04 +1300."
	<1231b6a80810012218t8f9b37y7395215c24229305@mail.gmail.com> 
Message-ID: <71846.1222930951@critter.freebsd.dk>

In message <1231b6a80810012218t8f9b37y7395215c24229305 at mail.gmail.com>, "Steve 
Rooke" writes:
>2008/10/2 Bruce Griffiths <bruce.griffiths at xtra.co.nz>:
>
>> Save yourself a counter and just divide the frequency down to about 1Hz
>> and time stamp the 1Hz transitions with the Linux box.
>> As long as you know the division factor its easy enough to calculate the
>> frequency.
>
>I'd planned on a simple interface to the PC via using the parallel,
>suitably strapped, as a basic output port. Now, I could use it as an
>input but I'd probably have to poll the port which would be somewhat
>inefficient [...]

Linux should have the PPS-API from RFC2783 so that should be piece
of cake to do.

I know that it works in FreeBSD (guess who wrote it :-) where you can
just:
	cd /usr/sc/tools/test/ppsapi
	make
	./ppsapitest /dev/lpt0



-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.


From hmurray at megapathdsl.net  Thu Oct  2 03:39:13 2008
From: hmurray at megapathdsl.net (Hal Murray)
Date: Thu, 02 Oct 2008 00:39:13 -0700
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: Message from "Steve Rooke" <sar10538@gmail.com> of "Thu,
	02 Oct 2008 18:18:04 +1300."
	<1231b6a80810012218t8f9b37y7395215c24229305@mail.gmail.com> 
Message-ID: <20081002073914.8788CBCD4@ip-64-139-1-69.sjc.megapath.net>


> I'd planned on a simple interface to the PC via using the parallel,
> suitably strapped, as a basic output port. Now, I could use it as an
> input but I'd probably have to poll the port which would be somewhat
> inefficient but an option I guess. Think I could just record the
> staring time of the sampling and then the ending time plus the number
> of cycles. 

Most *nix kernels have options available to grab the system time on 
interrupts from changes on the modem control lines.  This is what ntpd uses 
to take advantage of local reference clocks with a PPS line.

With NetBSD and FreeBSD it's included in the mainline sources.  You may have 
to recompile your kernel after turning on some option.  With Linux, it's a 
not in the official kernel sources.  There are normally patches available, 
but I've lost track of where to get them and/or which versions of the kernel 
are supported.

Some systems may have options to use a printer port rather than a modem 
control signal.


If I wanted to use ntp to measure frequency....

Start by running ntpd to stabilize the local clock.  With care and luck, that 
will get your local clock to somewhere between 0.1 ms to 10 ms.  Let's call 
it 1 ms since that makes the handwaving simpler.  You can do much better with 
a PPS signal from a local GPS unit. (under $100)

You can track temperature changes in the drift file.  The temperature changes 
depending upon what your PC is doing.  Without a local PPS, network traffic 
can screw things up.

Plan 1 would be to use the PPS stuff above.  Run a big divider to get down to 
roughly 1 PPS.  Wire that up to a serial port input.  Run another program to 
record the time stamps from the modem interrupts.  Collect a lot of data, 
then analyze it.

The PPS samples should be accurate to within a few microseconds.  You may 
have to run some filtering to discard the late samples.  I'd do something 
like graph the offset from the current second which should be a constant and 
then eyeball it to see what should get filtered out.


Plan 2 would be to use your clock to drive a PIC/AVR/whatever and use that to 
implement a big counter.  (details TBD)  A monitor program running on the PC 
would flap a modem control signal (outgoing, not incoming like the PPS) to 
poke the micro.  When it gets poked, the micro saves the value of the counter 
and sends it to the PC over an RS232 link.  The monitor program would log the 
time it did the poke and the value of the counter it received.

If you don't like programming micros, plan 3 would be to implement plan 2 in 
raw hardware.  It's just a big counter, a big shift register, and a bit of 
logic to load the shift register when poked.  (An FPGA would be fine but you 
can do it in DIPs.)  The RS232 start/stop bits are just constants loaded into 
the shift register.

So, if your system clock is within 1 ms and you run for 1000 seconds, the 
answer should be within 1 PPM.  (give or take a factor of 2 and some mumble 
about how you are going to verify that your system clock is really that good).



I don't quite know what your external counter can do.  Totalizer mode sounds 
like maybe it can latch a copy of the current count when you poke it and 
still keep counting until you poke it again.  If so, a monitoring program 
could grab the time, poke, read the counter, and log the values.  (No PPS 
kernel stuff needed.)  I think that's as good as you can get.  It's plan 2 
above implemented in an expensive box.  I'm assuming it will keep counting 
when it overflows or clear the counter on each poke.  You need to read it 
often enough where often enough depends upon how many bits the counter has.  
(The counter can overflow many times as long as you can tell N overflows from 
N+1.)

That won't work as well if your counter doesn't keep counting after each 
poke, Say you can start/stop it, but it doesn't have a shadow register that 
gets latched when you poke it and you can't read it while it's running.  You 
could, read the time, start it, wait a while, stop it, read the time, then 
read the counter.  That should give you good results.  The idea is ntp will 
keep your system clock ticking at the right rate.  ntp calls the correction 
"drift".  You don't care how far off your clock is as long as the rate is 
good.

One trick is that you want to read the time both before and after each poke.  
Subtracting the two can be used to detect the scheduler doing something nasty 
or an interrupt at an unlucky time or ...



If you have something like a TBolt, you can feed its 10 MHz output into the 
external clock of a counter and then tell the counter to count for a long 
time.  That gets NTP out of the critical parts of the loop.

My HP 4334B gives numbers like this:
  54741 22324.410 F +1.0000000004E+07 F  +9.999999999E+06
  54741 22624.490 F +1.0000000004E+07 F  +9.999999999E+06
  54741 22924.570 F +1.0000000004E+07 F +1.0000000000E+07

That's clocked from a HP Z3801A.  The 1.0...04E+07 column is a LPRO Rubidium 
brick.  The 999s column is a TBolt, collected over 60 seconds.  The LPRO 
column is rock solid.  The TBolt column is mostly 999s with an ocasional 
1.0...0 and a very occasional 1.000...001  Boring.

If you are measuring an OXCO rather than a GPSDO, counting for 60 seconds is 
long enough to watch it wander around.  I did that for a while, but I can't 
find the log files.

I'll set it up again if anybody is curious.


Another thing you could do with a TBolt is turn things inside out.  Feed the 
TBolt into your setup rather than the OXCO.  Now all the clock wander is in 
the measuring system so you can get an idea of how well this idea works.


-- 
These are my opinions, not necessarily my employer's.  I hate spam.





From sar10538 at gmail.com  Thu Oct  2 04:30:00 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Thu, 2 Oct 2008 21:30:00 +1300
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: <71846.1222930951@critter.freebsd.dk>
References: <1231b6a80810012218t8f9b37y7395215c24229305@mail.gmail.com>
	<71846.1222930951@critter.freebsd.dk>
Message-ID: <1231b6a80810020130i6b006c1drcf75353357bad93b@mail.gmail.com>

2008/10/2 Poul-Henning Kamp <phk at phk.freebsd.dk>:
> In message <1231b6a80810012218t8f9b37y7395215c24229305 at mail.gmail.com>, "Steve
> Rooke" writes:
>>2008/10/2 Bruce Griffiths <bruce.griffiths at xtra.co.nz>:
>>
>>> Save yourself a counter and just divide the frequency down to about 1Hz
>>> and time stamp the 1Hz transitions with the Linux box.
>>> As long as you know the division factor its easy enough to calculate the
>>> frequency.
>>
>>I'd planned on a simple interface to the PC via using the parallel,
>>suitably strapped, as a basic output port. Now, I could use it as an
>>input but I'd probably have to poll the port which would be somewhat
>>inefficient [...]
>
> Linux should have the PPS-API from RFC2783 so that should be piece
> of cake to do.
>
> I know that it works in FreeBSD (guess who wrote it :-) where you can
> just:
>        cd /usr/sc/tools/test/ppsapi
>        make
>        ./ppsapitest /dev/lpt0

OK, interesting idea but I'm really not planning to use the PC to
count pulses. I have a Fluke 1912A Multi Counter which can count
pulses to 7 digits and I can allow that to overflow to get more digits
by changing the pre-scaller I plan to use on the front end of this. It
would be easier to use Linux to control an input gate to this
pre-scaller with a known good period of time.  Besides which, my quick
scan for PPSAPI/KIT only showed patches for the 2.2 and 2.4 kernels,
still I suppose I could use an older distro or even FreeBSD for that
matter (it's all Unix to me).

Cheers,
Steve
UNIX since SVR0
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From sar10538 at gmail.com  Thu Oct  2 04:55:51 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Thu, 2 Oct 2008 21:55:51 +1300
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: <20081002073914.8788CBCD4@ip-64-139-1-69.sjc.megapath.net>
References: <sar10538@gmail.com>
	<1231b6a80810012218t8f9b37y7395215c24229305@mail.gmail.com>
	<20081002073914.8788CBCD4@ip-64-139-1-69.sjc.megapath.net>
Message-ID: <1231b6a80810020155w563e6b1k3ff9510b4480fba3@mail.gmail.com>

Scuse me for top posting.

Guess I'm going to do something a bit like plan 3 but mostly in
hardware. My plan for the PC is just to use it to gate the oxco output
into the pre-scalier divider chain for a specific time period. The
output of the pre-scalier will be a series of pulses which can be
counted (as in 1,2,3,... not frequency counted) by my Fluke 1912A
Multi Counter in Tot (Totalise) mode.

Say I divided the oxco to produce an exact PPS output from the divider
chain (not the easiest thing to do when starting from 10MHz). If I
count for exactly 10^7 seconds, as gated by the NTP disciplined Linux
system, I should see 10000000 on the counter. So this should give me
.1ppm accuracy, in theory, in the text book case. Now, if I change the
divider to give 10 PPS and sample for 10^7 seconds, the counter will
overflow, as it only has 7 digits, but I know the top digit will be a
1 and I'll be able to see the .01ppm accuracy, if you get my drift. I
could do this with various divider ratios, IE. 100 PPS, 1000 PPS, etc,
to get at more and more digits.

I'm not planning to use this oxco to sync the NTP on my PC, just using
NTP to check the frequency of my oxco so I can use it to calibrate my
counters, as a timebase and hence to allow me to lock amateur radio
transceivers to a precise frequency for QRP (very low power long
distance work). If your not spot on the frequency you can miss a
signal. If I know that I am bang on the frequency, I can use a very
narrow band filter to pull a signal from the noise floor but if my
frequency is even slightly off, the filter will just remove the signal
I am looking for.

Now don't shoot me as I'm not directly thinking of this project in a
true time-nuts way but your group has some interesting aspects for the
work I am doing.

73
Steve

2008/10/2 Hal Murray <hmurray at megapathdsl.net>:
>
>> I'd planned on a simple interface to the PC via using the parallel,
>> suitably strapped, as a basic output port. Now, I could use it as an
>> input but I'd probably have to poll the port which would be somewhat
>> inefficient but an option I guess. Think I could just record the
>> staring time of the sampling and then the ending time plus the number
>> of cycles.
>
> Most *nix kernels have options available to grab the system time on
> interrupts from changes on the modem control lines.  This is what ntpd uses
> to take advantage of local reference clocks with a PPS line.
>
> With NetBSD and FreeBSD it's included in the mainline sources.  You may have
> to recompile your kernel after turning on some option.  With Linux, it's a
> not in the official kernel sources.  There are normally patches available,
> but I've lost track of where to get them and/or which versions of the kernel
> are supported.
>
> Some systems may have options to use a printer port rather than a modem
> control signal.
>
>
> If I wanted to use ntp to measure frequency....
>
> Start by running ntpd to stabilize the local clock.  With care and luck, that
> will get your local clock to somewhere between 0.1 ms to 10 ms.  Let's call
> it 1 ms since that makes the handwaving simpler.  You can do much better with
> a PPS signal from a local GPS unit. (under $100)
>
> You can track temperature changes in the drift file.  The temperature changes
> depending upon what your PC is doing.  Without a local PPS, network traffic
> can screw things up.
>
> Plan 1 would be to use the PPS stuff above.  Run a big divider to get down to
> roughly 1 PPS.  Wire that up to a serial port input.  Run another program to
> record the time stamps from the modem interrupts.  Collect a lot of data,
> then analyze it.
>
> The PPS samples should be accurate to within a few microseconds.  You may
> have to run some filtering to discard the late samples.  I'd do something
> like graph the offset from the current second which should be a constant and
> then eyeball it to see what should get filtered out.
>
>
> Plan 2 would be to use your clock to drive a PIC/AVR/whatever and use that to
> implement a big counter.  (details TBD)  A monitor program running on the PC
> would flap a modem control signal (outgoing, not incoming like the PPS) to
> poke the micro.  When it gets poked, the micro saves the value of the counter
> and sends it to the PC over an RS232 link.  The monitor program would log the
> time it did the poke and the value of the counter it received.
>
> If you don't like programming micros, plan 3 would be to implement plan 2 in
> raw hardware.  It's just a big counter, a big shift register, and a bit of
> logic to load the shift register when poked.  (An FPGA would be fine but you
> can do it in DIPs.)  The RS232 start/stop bits are just constants loaded into
> the shift register.
>
> So, if your system clock is within 1 ms and you run for 1000 seconds, the
> answer should be within 1 PPM.  (give or take a factor of 2 and some mumble
> about how you are going to verify that your system clock is really that good).
>
>
>
> I don't quite know what your external counter can do.  Totalizer mode sounds
> like maybe it can latch a copy of the current count when you poke it and
> still keep counting until you poke it again.  If so, a monitoring program
> could grab the time, poke, read the counter, and log the values.  (No PPS
> kernel stuff needed.)  I think that's as good as you can get.  It's plan 2
> above implemented in an expensive box.  I'm assuming it will keep counting
> when it overflows or clear the counter on each poke.  You need to read it
> often enough where often enough depends upon how many bits the counter has.
> (The counter can overflow many times as long as you can tell N overflows from
> N+1.)
>
> That won't work as well if your counter doesn't keep counting after each
> poke, Say you can start/stop it, but it doesn't have a shadow register that
> gets latched when you poke it and you can't read it while it's running.  You
> could, read the time, start it, wait a while, stop it, read the time, then
> read the counter.  That should give you good results.  The idea is ntp will
> keep your system clock ticking at the right rate.  ntp calls the correction
> "drift".  You don't care how far off your clock is as long as the rate is
> good.
>
> One trick is that you want to read the time both before and after each poke.
> Subtracting the two can be used to detect the scheduler doing something nasty
> or an interrupt at an unlucky time or ...
>
>
>
> If you have something like a TBolt, you can feed its 10 MHz output into the
> external clock of a counter and then tell the counter to count for a long
> time.  That gets NTP out of the critical parts of the loop.
>
> My HP 4334B gives numbers like this:
>  54741 22324.410 F +1.0000000004E+07 F  +9.999999999E+06
>  54741 22624.490 F +1.0000000004E+07 F  +9.999999999E+06
>  54741 22924.570 F +1.0000000004E+07 F +1.0000000000E+07
>
> That's clocked from a HP Z3801A.  The 1.0...04E+07 column is a LPRO Rubidium
> brick.  The 999s column is a TBolt, collected over 60 seconds.  The LPRO
> column is rock solid.  The TBolt column is mostly 999s with an ocasional
> 1.0...0 and a very occasional 1.000...001  Boring.
>
> If you are measuring an OXCO rather than a GPSDO, counting for 60 seconds is
> long enough to watch it wander around.  I did that for a while, but I can't
> find the log files.
>
> I'll set it up again if anybody is curious.
>
>
> Another thing you could do with a TBolt is turn things inside out.  Feed the
> TBolt into your setup rather than the OXCO.  Now all the clock wander is in
> the measuring system so you can get an idea of how well this idea works.
>
>
> --
> These are my opinions, not necessarily my employer's.  I hate spam.
>
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>



-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From hmurray at megapathdsl.net  Thu Oct  2 06:15:14 2008
From: hmurray at megapathdsl.net (Hal Murray)
Date: Thu, 02 Oct 2008 03:15:14 -0700
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: Message from "Steve Rooke" <sar10538@gmail.com> of "Thu,
	02 Oct 2008 21:55:51 +1300."
	<1231b6a80810020155w563e6b1k3ff9510b4480fba3@mail.gmail.com> 
Message-ID: <20081002101515.6DCD8BCD4@ip-64-139-1-69.sjc.megapath.net>


> I'm not planning to use this oxco to sync the NTP on my PC, just using
> NTP to check the frequency of my oxco so I can use it to calibrate my
> counters, as a timebase and hence to allow me to lock amateur radio
> transceivers to a precise frequency for QRP (very low power long
> distance work). If your not spot on the frequency you can miss a
> signal. If I know that I am bang on the frequency, I can use a very
> narrow band filter to pull a signal from the noise floor but if my
> frequency is even slightly off, the filter will just remove the signal
> I am looking for. 

How accurately do you need to know the frequency?  (How much is "slightly"?)

Is your crystal stable enough?  Will it drift off frequency over 
time/temperature while you are listening?



> Say I divided the oxco to produce an exact PPS output from the divider
> chain (not the easiest thing to do when starting from 10MHz). If I
> count for exactly 10^7 seconds, as gated by the NTP disciplined Linux
> system, I should see 10000000 on the counter. So this should give me
> .1ppm accuracy, in theory, in the text book case. Now, if I change the
> divider to give 10 PPS and sample for 10^7 seconds, the counter will
> overflow, as it only has 7 digits, but I know the top digit will be a
> 1 and I'll be able to see the .01ppm accuracy, if you get my drift. I
> could do this with various divider ratios, IE. 100 PPS, 1000 PPS, etc,
> to get at more and more digits. 

I don't think you need the divider/prescaler.

The basic idea is that your counter only has N digits.  If you count for T 
seconds, you can get any N digits out of the actual count.  If it doesn't 
overflow, there isn't much into in 0s on the top.

If you use a prescaler, that moves the digits you read to the left so you 
just have to wait longer to fill up the counter.  (Binary vs decimal 
prescalers move things by fractional digits.  Let's ignore that mess.  You 
can't get any digits to the right of the decimal point.)

There is a slight advantage to throwing away low digits rather than high ones 
because there is some noise on when you turn things on/off and that goes into 
the low digits.  I expect that's sub microsecond.  1 microsecond of noise 
would be 1 digit at 10 MHz.  So the bottom digit is trash and you only have 6 
useful ones.  Getting another digit isn't worth messing with a prescaler.

If you want to measure your OCXO within 1E8, you need 8 good digits.  You 
have a 7 digit counter counting at 10 MHz.  That will overflow at 1 count per 
second.  The bottom digit is trash leaving 6.  You need 2 fake digits from 
overflow so you have to count for 100 seconds.

I'd probably count for 100.5 seconds so I didn't have to worry about whether 
the overflow was 99 or 100.  You aren't going to get the 1/2 accurate (or the 
0 if you count for 100.0), so you will have to divide the count by the actual 
time (roughly 100.5) rather than 100.

You can also measure at 1 second and 10 seconds to verify that the speed is 
close enough so that you will get the right number of overflows.  If it's way 
off, say 1E6. that still won't show up in 100 overflows.

If I was doing something like this, I'd probably set it up to loop, counting 
for 100 or 1000 seconds, and plot the data.  If they are consistent you 
probably have the right answer.

I'd also grab the OCXO with my fingers to change temperature and/or run some 
CPU intensive job on the PC to see what happens when its temperature changes.

You will probably have to plot it for a week or so to see if it is drifting 
over time.





-- 
These are my opinions, not necessarily my employer's.  I hate spam.





From df6jb at ulrich-bangert.de  Thu Oct  2 06:38:48 2008
From: df6jb at ulrich-bangert.de (Ulrich Bangert)
Date: Thu, 2 Oct 2008 12:38:48 +0200
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: <1231b6a80810012237y11625d66h986df3b5987ac8ec@mail.gmail.com>
Message-ID: <85684E7476FA4C6DA9CBD75BE387F11E@athlon>

Steve,

> Hmmm... If I measured a 10MHz oscillator for a 1/10 second, I 
> could achieve, at best, 1ppm accuracy. Now my measuring 
> system has a non accumulating error in the ms range, say <1s, 
> so this would be totally unworkable. If I sampled for 1s, 
> best would be .1ppm accuracy...

this is a common misbelieve but simply not true. You need not buy the
most advanced stuff. Even a moderate surplus counter like the RACAL DANA
1991/1992/1996 will get you < 1ppb (b, not m!) resolution @ 1 s. Since
more than 30 years counters do no more simply "count" but work with lots
clever electronic tricks inside!

73s de Ulrich, DF6JB 


> -----Ursprungliche Nachricht-----
> Von: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] Im Auftrag von Steve Rooke
> Gesendet: Donnerstag, 2. Oktober 2008 07:37
> An: Discussion of precise time and frequency measurement
> Betreff: Re: [time-nuts] Testing frequency using NTP
> 
> 
> Hmmm... If I measured a 10MHz oscillator for a 1/10 second, I 
> could achieve, at best, 1ppm accuracy. Now my measuring 
> system has a non accumulating error in the ms range, say <1s, 
> so this would be totally unworkable. If I sampled for 1s, 
> best would be .1ppm accuracy, but my measuring errors would 
> still swamp the result. To make my measuring errors small, I 
> could make the 1s overhead very small compared to the measing 
> time period by, say, sampling for 10^6s thereby making the 1s 
> error 1ppm. Now the 1s error is probably considerably smaller 
> than that, probably by the order of at least a decade or two. 
> If it was just .1s error, I could get a result to 1ppm in 
> about a day and better if I sample of a number of days.
> 
> Cheers,
> Steve
> 
> 2008/10/2 Scott McGrath <scmcgrath at gmail.com>:
> > It depends on how accurately you want to measure the oscillator 
> > frequency with your approach short term you probably would 
> not be able 
> > to measure the oscillator offset any better than a few 
> parts in 10-5 
> > longer term probably a few parts in 10-7 might be possible as you 
> > could compute the allen deviation and fit a curve through 
> the median 
> > values.
> >
> > NTP from a stratum 3 clock is only going to be precise to a few 
> > milliseconds and for meaningful accuracy you need another order of
> > magnitude.   This is part of the function of the drift file in xntpd
> > in which the daemon attempts to compensate for the drift and offset 
> > inherent in cheap oscillators used in computer applications.
> >
> >
> > - Fellow nuts am I all wet here or have I missed a technique
> 
> -- 
> Steve Rooke - ZL3TUV & G8KVD
> Omnium finis imminet
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-> bin/mailman/listinfo/time-nuts
> and 
> follow the instructions there.
> 



From bruce.griffiths at xtra.co.nz  Thu Oct  2 06:58:55 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Thu, 02 Oct 2008 23:58:55 +1300
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: <85684E7476FA4C6DA9CBD75BE387F11E@athlon>
References: <85684E7476FA4C6DA9CBD75BE387F11E@athlon>
Message-ID: <48E4A96F.2090401@xtra.co.nz>

Ulrich Bangert wrote:
> Steve,
>
>   
>> Hmmm... If I measured a 10MHz oscillator for a 1/10 second, I 
>> could achieve, at best, 1ppm accuracy. Now my measuring 
>> system has a non accumulating error in the ms range, say <1s, 
>> so this would be totally unworkable. If I sampled for 1s, 
>> best would be .1ppm accuracy...
>>     
>
> this is a common misbelieve but simply not true. You need not buy the
> most advanced stuff. Even a moderate surplus counter like the RACAL DANA
> 1991/1992/1996 will get you < 1ppb (b, not m!) resolution @ 1 s. Since
> more than 30 years counters do no more simply "count" but work with lots
> clever electronic tricks inside!
>
> 73s de Ulrich, DF6JB 
>
>   
This belief also appears to widespread in the musical instrument making 
community.
ie a counter is useless for measuring the frequency of a plucked string 
because the sound doesnt last long enough for accurate measurement.
With a reciprocal counter and time interval interpolators its is 
possible to make more accurate measurements than a naive analysis would 
suggest.
However careful design of the signal conditioning is required to ensure 
that the counter input circuit noise doesn't degrade the measurement noise.
In the particular case of a source like a plucked string it is perhaps 
more effective and informative to use a sound card for the measurement.

For precision frequency comparisons NIST divide the frequencies to be 
compared down to about 1Hz and time stamp the resultant signal 
transitions and the leading edge of the PPS output of a GPS timing 
receiver with a resolution of a few picosec. The resultant timestamps 
are then processed (along with measurements taken with a similar system 
that time stamps the transitions of a 1Hz signal s derived from one or 
more of their frequency standards) to derive the frequencies of the 
various sources.

Bruce



From w3kl at w3kl.com  Thu Oct  2 09:05:10 2008
From: w3kl at w3kl.com (Jeffrey Okamitsu)
Date: Thu, 2 Oct 2008 06:05:10 -0700 (PDT)
Subject: [time-nuts] AC Connector On HP 5061B
Message-ID: <728480.33864.qm@web35405.mail.mud.yahoo.com>

I recently acquired an HP 5061B (Options 3 and 4).? The system came without an AC cable.
?
I can easily make a replacement cable for the system.? However, I need to know the pin assignments.? I can open the unit to look, but if someone has the answer it would save me the hassle.
?
Each of the pins on the jack at are assigned a letter. "G", "A", and "B" (I think).
?
"G" is ground as it is connected to chassis (confirmed with am ohmmeter).
?
Does anyone know which of the other two pins is AC hot and which is AC neutral?
?
Thanks in advance.
?
Jeff

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

From w3kl at w3kl.com  Thu Oct  2 09:18:46 2008
From: w3kl at w3kl.com (Jeffrey Okamitsu)
Date: Thu, 2 Oct 2008 06:18:46 -0700 (PDT)
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <728480.33864.qm@web35405.mail.mud.yahoo.com>
Message-ID: <40777.59990.qm@web35406.mail.mud.yahoo.com>

By the way...I know that for single phase AC the assignment of "hot" and "neutral" technically doesn't matter...but I'm a purist...
?
Thanks.
?
Jeff

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

--- On Thu, 10/2/08, Jeffrey Okamitsu <w3kl at w3kl.com> wrote:

From: Jeffrey Okamitsu <w3kl at w3kl.com>
Subject: [time-nuts] AC Connector On HP 5061B
To: time-nuts at febo.com
Date: Thursday, October 2, 2008, 9:05 AM

I recently acquired an HP 5061B (Options 3 and 4).? The system came without an
AC cable.
?
I can easily make a replacement cable for the system.? However, I need to know
the pin assignments.? I can open the unit to look, but if someone has the
answer it would save me the hassle.
?
Each of the pins on the jack at are assigned a letter. "G",
"A", and "B" (I think).
?
"G" is ground as it is connected to chassis (confirmed with am
ohmmeter).
?
Does anyone know which of the other two pins is AC hot and which is AC neutral?
?
Thanks in advance.
?
Jeff

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402
_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

From james.p.lux at jpl.nasa.gov  Thu Oct  2 09:39:49 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Thu, 2 Oct 2008 06:39:49 -0700
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: <1231b6a80810012218t8f9b37y7395215c24229305@mail.gmail.com>
Message-ID: <C50A1D35.158F%James.P.Lux@jpl.nasa.gov>




On 10/1/08 10:18 PM, "Steve Rooke" <sar10538 at gmail.com> wrote:

> 2008/10/2 Bruce Griffiths <bruce.griffiths at xtra.co.nz>:
>
>> Save yourself a counter and just divide the frequency down to about 1Hz
>> and time stamp the 1Hz transitions with the Linux box.
>> As long as you know the division factor its easy enough to calculate the
>> frequency.
>
> I'd planned on a simple interface to the PC via using the parallel,
> suitably strapped, as a basic output port. Now, I could use it as an
> input but I'd probably have to poll the port which would be somewhat
> inefficient but an option I guess. Think I could just record the
> staring time of the sampling and then the ending time plus the number
> of cycles.

If you're hacking some ASM code... Hook the input to one of the printer port
lines that can generate and IRQ. Make your ISR just latch a counter and
return.  Then, your non-real time program just has to periodically read the
counter and write it to a file.



From tvb at LeapSecond.com  Thu Oct  2 09:56:56 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Thu, 2 Oct 2008 06:56:56 -0700
Subject: [time-nuts] AC Connector On HP 5061B
References: <728480.33864.qm@web35405.mail.mud.yahoo.com>
Message-ID: <002901c92496$bf682e60$0300a8c0@pc52>

> I recently acquired an HP 5061B (Options 3 and 4). The system
> came without an AC cable.
>
> I can easily make a replacement cable for the system. However,
> I need to know the pin assignments. I can open the unit to look,
> but if someone has the answer it would save me the hassle.

You just got a 5061B and you don't want to open it? It is so cool
looking inside, how can you resist?

See the pin assignments in the 5061 manual:
http://www.leapsecond.com/museum/hp5061a/5061a.pdf

But, NEVER, make a power cord for something as precious as a
5061 without actually checking pins from the inside. On some
models 5065/5061 that I have HP switched the pin assignments.
See, for example,

http://www.leapsecond.com/museum/hp5065a/conn.htm

> Each of the pins on the jack at are assigned a letter. "G", "A", and "B" (I think).
> "G" is ground as it is connected to chassis (confirmed with am ohmmeter).
> Does anyone know which of the other two pins is AC hot and which is AC neutral?

The other way to check it is pull the fuse and measure which pin
is connected to the ends of the fuse holder.

/tvb



From XDE-L2G3 at myamail.com  Thu Oct  2 10:02:53 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Thu, 02 Oct 2008 10:02:53 -0400
Subject: [time-nuts] Testing frequency using NTP
References: <mailman.195.1222952732.2205.time-nuts@febo.com>
Message-ID: <mailman.5.1222956218.2202.time-nuts@febo.com>

  >Date: Thu, 02 Oct 2008 23:58:55 +1300
  >From: Bruce Griffiths
  >Subject: Re: [time-nuts] Testing frequency using NTP

  [...]

  > For precision frequency comparisons NIST divide the frequencies to
  > be compared down to about 1Hz and time stamp the  resultant signal
  > transitions and the leading edge of the PPS output of a GPS timing
  > receiver with a resolution of a few picosec.

  > The  resultant   timestamps   are   then   processed   (along with
  > measurements taken  with  a similar system  that  time  stamps the
  > transitions of  a  1Hz signal derived from one  or  more  of their
  > frequency standards)  to  derive the  frequencies  of  the various
  > sources.

  >  Bruce

  Hello Bruce,

  This is my first attempt to post so I'm not sure if it will work.

  I have been researching the forum archive and find it is by  far the
  best resource  on time and frequency available anywhere.  Also, your
  posts are extremely helpful to a newcomer. Thanks!

  I am  curious  about  the  NIST   GPS  timing  receiver  that  has a
  resolution of a few ps. It doesn't seem possible to get that kind of
  precision with conventional GPS methods that produce a 1pps signal.

  Can you  describe  more how this is done, and do  you  have  any web
  links that give more information?

  Thanks,

  Mike Monett


From scmcgrath at gmail.com  Thu Oct  2 10:29:25 2008
From: scmcgrath at gmail.com (Scott McGrath)
Date: Thu, 2 Oct 2008 10:29:25 -0400
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <002901c92496$bf682e60$0300a8c0@pc52>
References: <728480.33864.qm@web35405.mail.mud.yahoo.com>
	<002901c92496$bf682e60$0300a8c0@pc52>
Message-ID: <c9ffea950810020729s46e386ccn2de1cb40ad935db7@mail.gmail.com>

Was this the pretty one on Ebay?  - you really, really need to open it
up at least to ensure nothing came adrift in shipping, I'll second Tom
on the sheer coolness of the 5061B but also remember most of the
components in a Cesium beam fall under the category of "Unobtainium"
so you will want to ensure everything is as it should be.

You will want to follow the preoperation checklist which can be found here

http://www.home.agilent.com/agilent/facet.jspx?cc=US&lc=eng&t=80091.k.3&no=150

On Thu, Oct 2, 2008 at 9:56 AM, Tom Van Baak <tvb at leapsecond.com> wrote:
>> I recently acquired an HP 5061B (Options 3 and 4). The system
>> came without an AC cable.
>>
>> I can easily make a replacement cable for the system. However,
>> I need to know the pin assignments. I can open the unit to look,
>> but if someone has the answer it would save me the hassle.
>
> You just got a 5061B and you don't want to open it? It is so cool
> looking inside, how can you resist?
>
> See the pin assignments in the 5061 manual:
> http://www.leapsecond.com/museum/hp5061a/5061a.pdf
>
> But, NEVER, make a power cord for something as precious as a
> 5061 without actually checking pins from the inside. On some
> models 5065/5061 that I have HP switched the pin assignments.
> See, for example,
>
> http://www.leapsecond.com/museum/hp5065a/conn.htm
>
>> Each of the pins on the jack at are assigned a letter. "G", "A", and "B" (I think).
>> "G" is ground as it is connected to chassis (confirmed with am ohmmeter).
>> Does anyone know which of the other two pins is AC hot and which is AC neutral?
>
> The other way to check it is pull the fuse and measure which pin
> is connected to the ends of the fuse holder.
>
> /tvb
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>


From w3kl at w3kl.com  Thu Oct  2 11:09:51 2008
From: w3kl at w3kl.com (Jeffrey Okamitsu)
Date: Thu, 2 Oct 2008 08:09:51 -0700 (PDT)
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <c9ffea950810020729s46e386ccn2de1cb40ad935db7@mail.gmail.com>
Message-ID: <136543.33396.qm@web35405.mail.mud.yahoo.com>

Scott, Tom.? Thanks for your input.? I am sure the unit was working before hand.? I will probably pop the top cover off and have a look.
?
The schematic helps.? Thanks.
?
Yes, this was the one on e-bay.? Was I bidding against you?
?
Jeff

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

--- On Thu, 10/2/08, Scott McGrath <scmcgrath at gmail.com> wrote:

From: Scott McGrath <scmcgrath at gmail.com>
Subject: Re: [time-nuts] AC Connector On HP 5061B
To: "Tom Van Baak" <tvb at leapsecond.com>, "Discussion of precise time and frequency measurement" <time-nuts at febo.com>
Date: Thursday, October 2, 2008, 10:29 AM

Was this the pretty one on Ebay?  - you really, really need to open it
up at least to ensure nothing came adrift in shipping, I'll second Tom
on the sheer coolness of the 5061B but also remember most of the
components in a Cesium beam fall under the category of "Unobtainium"
so you will want to ensure everything is as it should be.

You will want to follow the preoperation checklist which can be found here

http://www.home.agilent.com/agilent/facet.jspx?cc=US&lc=eng&t=80091.k.3&no=150

On Thu, Oct 2, 2008 at 9:56 AM, Tom Van Baak <tvb at leapsecond.com> wrote:
>> I recently acquired an HP 5061B (Options 3 and 4). The system
>> came without an AC cable.
>>
>> I can easily make a replacement cable for the system. However,
>> I need to know the pin assignments. I can open the unit to look,
>> but if someone has the answer it would save me the hassle.
>
> You just got a 5061B and you don't want to open it? It is so cool
> looking inside, how can you resist?
>
> See the pin assignments in the 5061 manual:
> http://www.leapsecond.com/museum/hp5061a/5061a.pdf
>
> But, NEVER, make a power cord for something as precious as a
> 5061 without actually checking pins from the inside. On some
> models 5065/5061 that I have HP switched the pin assignments.
> See, for example,
>
> http://www.leapsecond.com/museum/hp5065a/conn.htm
>
>> Each of the pins on the jack at are assigned a letter. "G",
"A", and "B" (I think).
>> "G" is ground as it is connected to chassis (confirmed with
am ohmmeter).
>> Does anyone know which of the other two pins is AC hot and which is AC
neutral?
>
> The other way to check it is pull the fuse and measure which pin
> is connected to the ends of the fuse holder.
>
> /tvb
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

From david.partridge at dsl.pipex.com  Thu Oct  2 12:31:00 2008
From: david.partridge at dsl.pipex.com (David C. Partridge)
Date: Thu, 2 Oct 2008 17:31:00 +0100
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <40777.59990.qm@web35406.mail.mud.yahoo.com>
References: <728480.33864.qm@web35405.mail.mud.yahoo.com>
	<40777.59990.qm@web35406.mail.mud.yahoo.com>
Message-ID: <34144257F8BF4D59B25BE9A5B0248FAD@APOLLO>

That critically depends what country you are in.

In the UK you can normally safely connect yourself between neutral and
earth, as neutral is "always" bonded to earth at the sub-station.   There
may be a few volts on neutral due to phase imbalance in the three phase
supply and how far you are from the sub-station, but normally that's not a
problem.   I really wouldn't like to connect myself between live (nominal
230V over here) and neutral though!

I don't know the wiring rules in US well enough to determine how "safe" this
would "over there".

Dave

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Jeffrey Okamitsu
Sent: 02 October 2008 14:19
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] AC Connector On HP 5061B

By the way...I know that for single phase AC the assignment of "hot" and
"neutral" technically doesn't matter...but I'm a purist...
?
Thanks.
?
Jeff

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402



From w3kl at w3kl.com  Thu Oct  2 13:36:17 2008
From: w3kl at w3kl.com (Jeffrey Okamitsu)
Date: Thu, 2 Oct 2008 10:36:17 -0700 (PDT)
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <34144257F8BF4D59B25BE9A5B0248FAD@APOLLO>
Message-ID: <296989.72875.qm@web35408.mail.mud.yahoo.com>

US is similar regarding the lashing together of earth and ground for single phase power. However, current US electric code is very specific about which terminal of the AC plug is wired to "hot" and which is wired to "neutral".
?
Jeff

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

--- On Thu, 10/2/08, David C. Partridge <david.partridge at dsl.pipex.com> wrote:

From: David C. Partridge <david.partridge at dsl.pipex.com>
Subject: Re: [time-nuts] AC Connector On HP 5061B
To: "'Discussion of precise time and frequency measurement'" <time-nuts at febo.com>
Date: Thursday, October 2, 2008, 12:31 PM

That critically depends what country you are in.

In the UK you can normally safely connect yourself between neutral and
earth, as neutral is "always" bonded to earth at the sub-station.  
There
may be a few volts on neutral due to phase imbalance in the three phase
supply and how far you are from the sub-station, but normally that's not a
problem.   I really wouldn't like to connect myself between live (nominal
230V over here) and neutral though!

I don't know the wiring rules in US well enough to determine how
"safe" this
would "over there".

Dave

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Jeffrey Okamitsu
Sent: 02 October 2008 14:19
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] AC Connector On HP 5061B

By the way...I know that for single phase AC the assignment of "hot"
and
"neutral" technically doesn't matter...but I'm a purist...
?
Thanks.
?
Jeff

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402


_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

From hmurray at megapathdsl.net  Thu Oct  2 13:56:45 2008
From: hmurray at megapathdsl.net (Hal Murray)
Date: Thu, 02 Oct 2008 10:56:45 -0700
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: Message from Jeffrey Okamitsu <w3kl@w3kl.com> of "Thu,
	02 Oct 2008 10:36:17 PDT."
	<296989.72875.qm@web35408.mail.mud.yahoo.com> 
Message-ID: <20081002175646.6855BBCD4@ip-64-139-1-69.sjc.megapath.net>


> US is similar regarding the lashing together of earth and ground for
> single phase power. However, current US electric code is very specific
> about which terminal of the AC plug is wired to "hot" and which is
> wired to "neutral". 

It used to matter back in the tube days when cheap radios/TVs didn't have a 
power transformer.  The neutral was connected to the chassis and the B+ was 
derived from the hot line.  That gives you a hot chassis if you swap the 
power wires.  (The chassis was all hidden in plastic, at least in theory.)


What happens to a 5061 if I swap the power wires?  I can imagine some second 
order considerations that would depend on how the power transformer is 
constructed.





-- 
These are my opinions, not necessarily my employer's.  I hate spam.





From aa8k at comcast.net  Thu Oct  2 14:10:43 2008
From: aa8k at comcast.net (Mike Naruta AA8K)
Date: Thu, 02 Oct 2008 14:10:43 -0400
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <34144257F8BF4D59B25BE9A5B0248FAD@APOLLO>
References: <728480.33864.qm@web35405.mail.mud.yahoo.com>	<40777.59990.qm@web35406.mail.mud.yahoo.com>
	<34144257F8BF4D59B25BE9A5B0248FAD@APOLLO>
Message-ID: <48E50EA3.3030001@comcast.net>

Basically, we get ours from a 230 Volt,
center-tapped transformer secondary.
The center tap is also earthed.  We can
connect 115 Volt appliances between either
end of the transformer and center-tap "neutral".
Higher-current appliances connect to both
ends to get the full 230 Volts.

The neutral is bonded to the earth connection
at the mains panel.

Ground Fault Interrupters (GFI) monitor
the current flow in the "hot" and neutral
conductors.  Any imbalance indicates a
current flow on the earth conductor and
the GFI disconnects the circuit to remove
a shock hazard.


Interesting things happen when the neutral
conductor between the mains panel and the
utility transformer secondary has high
resistance.  Instead of the voltage being
the same on both "hot" leads, the voltage
is divided proportionately to the load
resistance.  One "hot" lead can be at,
say, 30 Volts, while the other "hot" lead
is at 200 Volts.  This can be exciting.


Mike - AA8K



David C. Partridge wrote:
> That critically depends what country you are in.
> 
> In the UK you can normally safely connect yourself between neutral and
> earth, as neutral is "always" bonded to earth at the sub-station.   There
> may be a few volts on neutral due to phase imbalance in the three phase
> supply and how far you are from the sub-station, but normally that's not a
> problem.   I really wouldn't like to connect myself between live (nominal
> 230V over here) and neutral though!
> 
> I don't know the wiring rules in US well enough to determine how "safe" this
> would "over there".
> 
> Dave
> 


From scmcgrath at gmail.com  Thu Oct  2 14:11:07 2008
From: scmcgrath at gmail.com (Scott McGrath)
Date: Thu, 2 Oct 2008 14:11:07 -0400
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <136543.33396.qm@web35405.mail.mud.yahoo.com>
References: <c9ffea950810020729s46e386ccn2de1cb40ad935db7@mail.gmail.com>
	<136543.33396.qm@web35405.mail.mud.yahoo.com>
Message-ID: <c9ffea950810021111s3e3096f1y897ccdc439e7b512@mail.gmail.com>

No I bought a 5061A a few weeks before unfortunately it has issues
some of which are traceable to improper packing.   I'm surprised you
did not buy the power cord (i did) on ebay.   The Cannon connectors
are expensive but they can be had from Powell Electronics here in
Massachusetts.

I think someone here knows the part #

The reason Parts are Unobtainium is Agilent sold the Time and
Frequency divsion to Symmetricom and while some parts stock is still
available from Agilent most of the people have moved on plus the 5061
is a 20+ year old design and it was superceded by the microprocessor
controlled 5071A which is an even better Cs device which is a couple
of orders of magnitude better than our 5061x's.    On the other hand
the 5061 is approachable by someone with a well equipped lab.

But still we own devices which at one time were the exclusive domain
of Govenments, national laboratories and aerospace firms.

Welcome to the club!

On Thu, Oct 2, 2008 at 11:09 AM, Jeffrey Okamitsu <w3kl at w3kl.com> wrote:
> Scott, Tom.  Thanks for your input.  I am sure the unit was working before hand.  I will probably pop the top cover off and have a look.
>
> The schematic helps.  Thanks.
>
> Yes, this was the one on e-bay.  Was I bidding against you?
>
> Jeff
>
> Jeffrey K. Okamitsu, PhD, MBA
> +1-609-638-5402
>
> --- On Thu, 10/2/08, Scott McGrath <scmcgrath at gmail.com> wrote:
>
> From: Scott McGrath <scmcgrath at gmail.com>
> Subject: Re: [time-nuts] AC Connector On HP 5061B
> To: "Tom Van Baak" <tvb at leapsecond.com>, "Discussion of precise time and frequency measurement" <time-nuts at febo.com>
> Date: Thursday, October 2, 2008, 10:29 AM
>
> Was this the pretty one on Ebay?  - you really, really need to open it
> up at least to ensure nothing came adrift in shipping, I'll second Tom
> on the sheer coolness of the 5061B but also remember most of the
> components in a Cesium beam fall under the category of "Unobtainium"
> so you will want to ensure everything is as it should be.
>
> You will want to follow the preoperation checklist which can be found here
>
> http://www.home.agilent.com/agilent/facet.jspx?cc=US&lc=eng&t=80091.k.3&no=150
>
> On Thu, Oct 2, 2008 at 9:56 AM, Tom Van Baak <tvb at leapsecond.com> wrote:
>>> I recently acquired an HP 5061B (Options 3 and 4). The system
>>> came without an AC cable.
>>>
>>> I can easily make a replacement cable for the system. However,
>>> I need to know the pin assignments. I can open the unit to look,
>>> but if someone has the answer it would save me the hassle.
>>
>> You just got a 5061B and you don't want to open it? It is so cool
>> looking inside, how can you resist?
>>
>> See the pin assignments in the 5061 manual:
>> http://www.leapsecond.com/museum/hp5061a/5061a.pdf
>>
>> But, NEVER, make a power cord for something as precious as a
>> 5061 without actually checking pins from the inside. On some
>> models 5065/5061 that I have HP switched the pin assignments.
>> See, for example,
>>
>> http://www.leapsecond.com/museum/hp5065a/conn.htm
>>
>>> Each of the pins on the jack at are assigned a letter. "G",
> "A", and "B" (I think).
>>> "G" is ground as it is connected to chassis (confirmed with
> am ohmmeter).
>>> Does anyone know which of the other two pins is AC hot and which is AC
> neutral?
>>
>> The other way to check it is pull the fuse and measure which pin
>> is connected to the ends of the fuse holder.
>>
>> /tvb
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>


From james.p.lux at jpl.nasa.gov  Thu Oct  2 14:41:22 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Thu, 2 Oct 2008 11:41:22 -0700
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <34144257F8BF4D59B25BE9A5B0248FAD@APOLLO>
References: <728480.33864.qm@web35405.mail.mud.yahoo.com>
	<40777.59990.qm@web35406.mail.mud.yahoo.com>
	<34144257F8BF4D59B25BE9A5B0248FAD@APOLLO>
Message-ID: <ECE7A93BD093E1439C20020FBE87C47FEB52281F25@ALTPHYEMBEVSP20.RES.AD.JPL>

> -----Original Message-----
> From: time-nuts-bounces at febo.com
> [mailto:time-nuts-bounces at febo.com] On Behalf Of David C. Partridge
> Sent: Thursday, October 02, 2008 9:31 AM
> To: 'Discussion of precise time and frequency measurement'
> Subject: Re: [time-nuts] AC Connector On HP 5061B
>
> That critically depends what country you are in.
>
> In the UK you can normally safely connect yourself between neutral and
> earth, as neutral is "always" bonded to earth at the
> sub-station.   There
> may be a few volts on neutral due to phase imbalance in the
> three phase supply and how far you are from the sub-station,
> but normally that's not a
> problem.   I really wouldn't like to connect myself between
> live (nominal
> 230V over here) and neutral though!
>
> I don't know the wiring rules in US well enough to determine
> how "safe" this would "over there".
>
> Dave
>
In the U.S., depending on where the installation is (residential vs industrial), the neutral ("groundED conductor") is bonded (code-speak for permanently connected) to the earth ground at the service entrance panel. The safety ground ("groundING conductor" aka green-wire ground) runs separately from that point.

If you have a 15A receptacle (NEMA 5-15R, for instance), there is a rule about which slot connects to neutral and which to line (wider is closer to earth ground, e.g. neutral).  And, on screw in light fixtures, the neutral must be connected to the shell (so that if some of the male thread is exposed, it's at lower voltage relative to the grounded fixture.

There are lots of configurations possible (including, for instance, balanced 120V, where each side is 60V relative to earth ground) still using the NEMA 5-15R configuration.

And, there's a lot of stuff when you're running off an isolated power source (e.g. a generator or UPS).

And, if you're in an industrial or office environment, fed with 3 phase power, there's all kinds of strange configurations possible (e.g. delta, with the midpoint of one phase winding grounded, or Wye/Star with the neutral bonded through a high impedance to ground).

But.. Bear in mind that NEC allows 2% voltage drop at the end of the run from the panel, so 2% of 120V is 2.4V, so the neutral *should* be about 1.2V above earth ground.


From brooke at pacific.net  Thu Oct  2 14:45:46 2008
From: brooke at pacific.net (Brooke Clarke)
Date: Thu, 02 Oct 2008 11:45:46 -0700
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <48E50EA3.3030001@comcast.net>
References: <728480.33864.qm@web35405.mail.mud.yahoo.com>	<40777.59990.qm@web35406.mail.mud.yahoo.com>	<34144257F8BF4D59B25BE9A5B0248FAD@APOLLO>
	<48E50EA3.3030001@comcast.net>
Message-ID: <48E516DA.1000402@pacific.net>

Hi Mike:

The reason for the center tapped transformer on the pole pig is to protect the 
house occupants from a primary to secondary short in the pole pig transformer. 
  That would put 4KV into your house.

It's not clear to me how 230 VAC countries handle that problem?  If they also 
use the same transformer but only bring in the 230 VAC then neither side of the 
line is near ground potential.

Have Fun,

Brooke Clarke
http://www.prc68.com/P/Prod.html  Products I make and sell
http://www.prc68.com/Alpha.shtml  All my web pages listed based on html name
http://www.PRC68.com
http://www.precisionclock.com
http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Web Cam

Mike Naruta AA8K wrote:
> Basically, we get ours from a 230 Volt,
> center-tapped transformer secondary.
> The center tap is also earthed.  We can
> connect 115 Volt appliances between either
> end of the transformer and center-tap "neutral".
> Higher-current appliances connect to both
> ends to get the full 230 Volts.
> 
> The neutral is bonded to the earth connection
> at the mains panel.
> 
> Ground Fault Interrupters (GFI) monitor
> the current flow in the "hot" and neutral
> conductors.  Any imbalance indicates a
> current flow on the earth conductor and
> the GFI disconnects the circuit to remove
> a shock hazard.
> 
> 
> Interesting things happen when the neutral
> conductor between the mains panel and the
> utility transformer secondary has high
> resistance.  Instead of the voltage being
> the same on both "hot" leads, the voltage
> is divided proportionately to the load
> resistance.  One "hot" lead can be at,
> say, 30 Volts, while the other "hot" lead
> is at 200 Volts.  This can be exciting.
> 
> 
> Mike - AA8K
> 
> 
> 
> David C. Partridge wrote:
>> That critically depends what country you are in.
>>
>> In the UK you can normally safely connect yourself between neutral and
>> earth, as neutral is "always" bonded to earth at the sub-station.   There
>> may be a few volts on neutral due to phase imbalance in the three phase
>> supply and how far you are from the sub-station, but normally that's not a
>> problem.   I really wouldn't like to connect myself between live (nominal
>> 230V over here) and neutral though!
>>
>> I don't know the wiring rules in US well enough to determine how "safe" this
>> would "over there".
>>
>> Dave
>>
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 


From w3kl at w3kl.com  Thu Oct  2 14:56:51 2008
From: w3kl at w3kl.com (Jeffrey Okamitsu)
Date: Thu, 2 Oct 2008 11:56:51 -0700 (PDT)
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <20081002175646.6855BBCD4@ip-64-139-1-69.sjc.megapath.net>
Message-ID: <953814.52042.qm@web35402.mail.mud.yahoo.com>

"What happens to a 5061 if I swap the power wires?? I can imagine some second 
order considerations that would depend on how the power transformer is 
constructed."
?
This is my concern.? Hence, I want to get it right in the beginning.
?
Jeff


Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

--- On Thu, 10/2/08, Hal Murray <hmurray at megapathdsl.net> wrote:

From: Hal Murray <hmurray at megapathdsl.net>
Subject: Re: [time-nuts] AC Connector On HP 5061B
To: "Discussion of precise time and frequency measurement" <time-nuts at febo.com>
Date: Thursday, October 2, 2008, 1:56 PM

> US is similar regarding the lashing together of earth and ground for
> single phase power. However, current US electric code is very specific
> about which terminal of the AC plug is wired to "hot" and which
is
> wired to "neutral". 

It used to matter back in the tube days when cheap radios/TVs didn't have a

power transformer.  The neutral was connected to the chassis and the B+ was 
derived from the hot line.  That gives you a hot chassis if you swap the 
power wires.  (The chassis was all hidden in plastic, at least in theory.)


What happens to a 5061 if I swap the power wires?  I can imagine some second 
order considerations that would depend on how the power transformer is 
constructed.





-- 
These are my opinions, not necessarily my employer's.  I hate spam.




_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

From sar10538 at gmail.com  Thu Oct  2 15:02:27 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Fri, 3 Oct 2008 08:02:27 +1300
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <48E516DA.1000402@pacific.net>
References: <728480.33864.qm@web35405.mail.mud.yahoo.com>
	<40777.59990.qm@web35406.mail.mud.yahoo.com>
	<34144257F8BF4D59B25BE9A5B0248FAD@APOLLO>
	<48E50EA3.3030001@comcast.net> <48E516DA.1000402@pacific.net>
Message-ID: <1231b6a80810021202h8878c14obc39c2600f1996c4@mail.gmail.com>

2008/10/3 Brooke Clarke <brooke at pacific.net>:
> It's not clear to me how 230 VAC countries handle that problem?  If they also
> use the same transformer but only bring in the 230 VAC then neither side of the
> line is near ground potential.

In 230/240 VAC the neutral side of the transformer output is earthed
at the transformer end. So breakdowns in the transformer go direct to
earth at the distribution transformer itself. At the customer end you
will find a small voltage at the neutral terminal due to the current
running down the resistance of the conductor back to the transformer.
As this is not a balanced supply, outlets have specific connections to
each pole of the mains and earth. The earth connection is made
locally, usually bonded to the incoming water main.

73
Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From w3kl at w3kl.com  Thu Oct  2 15:04:33 2008
From: w3kl at w3kl.com (Jeffrey Okamitsu)
Date: Thu, 2 Oct 2008 12:04:33 -0700 (PDT)
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <c9ffea950810021111s3e3096f1y897ccdc439e7b512@mail.gmail.com>
Message-ID: <290391.71932.qm@web35406.mail.mud.yahoo.com>

Scott.? Thanks for the information.? Tsuchiya-san provided the part number for the connector and I have already ordered one from Powell.
?
I am looking forward to getting the unit up and running and providing a stable 10 MHz from which I will lock all of my frequency sensitive test equipment. (spectrum analyzer, network analyzer, synthesized signal generator, and frequency counter).
?

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

--- On Thu, 10/2/08, Scott McGrath <scmcgrath at gmail.com> wrote:

From: Scott McGrath <scmcgrath at gmail.com>
Subject: Re: [time-nuts] AC Connector On HP 5061B
To: "Discussion of precise time and frequency measurement" <time-nuts at febo.com>
Date: Thursday, October 2, 2008, 2:11 PM

No I bought a 5061A a few weeks before unfortunately it has issues
some of which are traceable to improper packing.   I'm surprised you
did not buy the power cord (i did) on ebay.   The Cannon connectors
are expensive but they can be had from Powell Electronics here in
Massachusetts.

I think someone here knows the part #

The reason Parts are Unobtainium is Agilent sold the Time and
Frequency divsion to Symmetricom and while some parts stock is still
available from Agilent most of the people have moved on plus the 5061
is a 20+ year old design and it was superceded by the microprocessor
controlled 5071A which is an even better Cs device which is a couple
of orders of magnitude better than our 5061x's.    On the other hand
the 5061 is approachable by someone with a well equipped lab.

But still we own devices which at one time were the exclusive domain
of Govenments, national laboratories and aerospace firms.

Welcome to the club!

On Thu, Oct 2, 2008 at 11:09 AM, Jeffrey Okamitsu <w3kl at w3kl.com> wrote:
> Scott, Tom.  Thanks for your input.  I am sure the unit was working before
hand.  I will probably pop the top cover off and have a look.
>
> The schematic helps.  Thanks.
>
> Yes, this was the one on e-bay.  Was I bidding against you?
>
> Jeff
>
> Jeffrey K. Okamitsu, PhD, MBA
> +1-609-638-5402
>
> --- On Thu, 10/2/08, Scott McGrath <scmcgrath at gmail.com> wrote:
>
> From: Scott McGrath <scmcgrath at gmail.com>
> Subject: Re: [time-nuts] AC Connector On HP 5061B
> To: "Tom Van Baak" <tvb at leapsecond.com>, "Discussion
of precise time and frequency measurement" <time-nuts at febo.com>
> Date: Thursday, October 2, 2008, 10:29 AM
>
> Was this the pretty one on Ebay?  - you really, really need to open it
> up at least to ensure nothing came adrift in shipping, I'll second Tom
> on the sheer coolness of the 5061B but also remember most of the
> components in a Cesium beam fall under the category of
"Unobtainium"
> so you will want to ensure everything is as it should be.
>
> You will want to follow the preoperation checklist which can be found here
>
>
http://www.home.agilent.com/agilent/facet.jspx?cc=US&lc=eng&t=80091.k.3&no=150
>
> On Thu, Oct 2, 2008 at 9:56 AM, Tom Van Baak <tvb at leapsecond.com>
wrote:
>>> I recently acquired an HP 5061B (Options 3 and 4). The system
>>> came without an AC cable.
>>>
>>> I can easily make a replacement cable for the system. However,
>>> I need to know the pin assignments. I can open the unit to look,
>>> but if someone has the answer it would save me the hassle.
>>
>> You just got a 5061B and you don't want to open it? It is so cool
>> looking inside, how can you resist?
>>
>> See the pin assignments in the 5061 manual:
>> http://www.leapsecond.com/museum/hp5061a/5061a.pdf
>>
>> But, NEVER, make a power cord for something as precious as a
>> 5061 without actually checking pins from the inside. On some
>> models 5065/5061 that I have HP switched the pin assignments.
>> See, for example,
>>
>> http://www.leapsecond.com/museum/hp5065a/conn.htm
>>
>>> Each of the pins on the jack at are assigned a letter.
"G",
> "A", and "B" (I think).
>>> "G" is ground as it is connected to chassis (confirmed
with
> am ohmmeter).
>>> Does anyone know which of the other two pins is AC hot and which
is AC
> neutral?
>>
>> The other way to check it is pull the fuse and measure which pin
>> is connected to the ends of the fuse holder.
>>
>> /tvb
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

From ian.sheffield1 at tesco.net  Thu Oct  2 15:09:29 2008
From: ian.sheffield1 at tesco.net (Ian Sheffield)
Date: Thu, 2 Oct 2008 20:09:29 +0100
Subject: [time-nuts] AC Connector On HP 5061B
References: <953814.52042.qm@web35402.mail.mud.yahoo.com>
Message-ID: <012801c924c2$68352ae0$0300000a@cookie>

Similar to what another poster suggested, but more direct -
assuming the schematic shows that only the live side is fuse protected 
inside the HP, then if you take out the fuse
on the rear panel, and see which prong on the connector connects to it, that 
should tell you.

 - unless both sides are fused :-(

Ian.

----- Original Message ----- 
From: "Jeffrey Okamitsu" <w3kl at w3kl.com>
To: "Discussion of precise time and frequency measurement" 
<time-nuts at febo.com>
Sent: Thursday, October 02, 2008 7:56 PM
Subject: Re: [time-nuts] AC Connector On HP 5061B


"What happens to a 5061 if I swap the power wires? I can imagine some second
order considerations that would depend on how the power transformer is
constructed."

This is my concern. Hence, I want to get it right in the beginning.

Jeff


Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

--- On Thu, 10/2/08, Hal Murray <hmurray at megapathdsl.net> wrote:

From: Hal Murray <hmurray at megapathdsl.net>
Subject: Re: [time-nuts] AC Connector On HP 5061B
To: "Discussion of precise time and frequency measurement" 
<time-nuts at febo.com>
Date: Thursday, October 2, 2008, 1:56 PM

> US is similar regarding the lashing together of earth and ground for
> single phase power. However, current US electric code is very specific
> about which terminal of the AC plug is wired to "hot" and which
is
> wired to "neutral".

It used to matter back in the tube days when cheap radios/TVs didn't have a

power transformer.  The neutral was connected to the chassis and the B+ was
derived from the hot line.  That gives you a hot chassis if you swap the
power wires.  (The chassis was all hidden in plastic, at least in theory.)


What happens to a 5061 if I swap the power wires?  I can imagine some second
order considerations that would depend on how the power transformer is
constructed.





-- 
These are my opinions, not necessarily my employer's.  I hate spam.




_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to 
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to 
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.


--------------------------------------------------------------------------------



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07:46



From tvb at LeapSecond.com  Thu Oct  2 15:15:31 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Thu, 2 Oct 2008 12:15:31 -0700
Subject: [time-nuts] AC Connector On HP 5061B
References: <20081002175646.6855BBCD4@ip-64-139-1-69.sjc.megapath.net>
Message-ID: <001f01c924c3$3f0b7d30$0300a8c0@pc52>

> What happens to a 5061 if I swap the power wires?  I can imagine some second 
> order considerations that would depend on how the power transformer is 
> constructed.

The transformer is symmetrical so no worries there. The only
difference is the fuse. Black (hot) is fused, white (neutral) isn't.
See the 5061A ac input schematic from figure 8-6 here:

http://www.leapsecond.com/museum/hp5061a/ac-power-pins.gif

/tvb



From tvb at LeapSecond.com  Thu Oct  2 15:43:28 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Thu, 2 Oct 2008 12:43:28 -0700
Subject: [time-nuts] Testing frequency using NTP
References: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>
Message-ID: <000301c924c7$26073c30$0300a8c0@pc52>

> I'm wondering about the possibility of checking the frequency of my
> oscillator by using a NTP synced RT Linux system. What I'm thinking of

An "all-PC" frequency counter is a great idea. True, the
performance is limited compared to GPS time sources and
hardware frequency counters, but there's something to be
said for an all (or almost all) software approach.

Time-stamping from an external pin transition should work fine.

Consider also using the sound card as a time comparator.
If you put your divided down UUT the left channel and an
NTP sync'd parallel or serial port tick into the right channel
you can compare the relative phase by looking at the stereo
input data. Phase change over time gives you frequency error.

The instability of the sound card's own LO drops out of the
equation. With 44.1 kHz sampling you could handle tick rates
of 1 kHz without any problem. This should be quite a bit more
accurate than 1 Hz sampling, so you might have to wait less
for your goal of 1 ppm resolution. If the limiting factor is the
quality of your NTP connection, then you've done a good job.

/tvb



From w3kl at w3kl.com  Thu Oct  2 15:51:58 2008
From: w3kl at w3kl.com (Jeffrey Okamitsu)
Date: Thu, 2 Oct 2008 12:51:58 -0700 (PDT)
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <012801c924c2$68352ae0$0300000a@cookie>
Message-ID: <855496.47849.qm@web35404.mail.mud.yahoo.com>

According to the circuit diagram, only one side is fused and it is identified on the schematic as the "hot" side.
?
Jeff

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

--- On Thu, 10/2/08, Ian Sheffield <ian.sheffield1 at tesco.net> wrote:

From: Ian Sheffield <ian.sheffield1 at tesco.net>
Subject: Re: [time-nuts] AC Connector On HP 5061B
To: "Discussion of precise time and frequency measurement" <time-nuts at febo.com>
Date: Thursday, October 2, 2008, 3:09 PM

Similar to what another poster suggested, but more direct -
assuming the schematic shows that only the live side is fuse protected 
inside the HP, then if you take out the fuse
on the rear panel, and see which prong on the connector connects to it, that 
should tell you.

 - unless both sides are fused :-(

Ian.

----- Original Message ----- 
From: "Jeffrey Okamitsu" <w3kl at w3kl.com>
To: "Discussion of precise time and frequency measurement" 
<time-nuts at febo.com>
Sent: Thursday, October 02, 2008 7:56 PM
Subject: Re: [time-nuts] AC Connector On HP 5061B


"What happens to a 5061 if I swap the power wires? I can imagine some
second
order considerations that would depend on how the power transformer is
constructed."

This is my concern. Hence, I want to get it right in the beginning.

Jeff


Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

--- On Thu, 10/2/08, Hal Murray <hmurray at megapathdsl.net> wrote:

From: Hal Murray <hmurray at megapathdsl.net>
Subject: Re: [time-nuts] AC Connector On HP 5061B
To: "Discussion of precise time and frequency measurement" 
<time-nuts at febo.com>
Date: Thursday, October 2, 2008, 1:56 PM

> US is similar regarding the lashing together of earth and ground for
> single phase power. However, current US electric code is very specific
> about which terminal of the AC plug is wired to "hot" and which
is
> wired to "neutral".

It used to matter back in the tube days when cheap radios/TVs didn't have a

power transformer.  The neutral was connected to the chassis and the B+ was
derived from the hot line.  That gives you a hot chassis if you swap the
power wires.  (The chassis was all hidden in plastic, at least in theory.)


What happens to a 5061 if I swap the power wires?  I can imagine some second
order considerations that would depend on how the power transformer is
constructed.





-- 
These are my opinions, not necessarily my employer's.  I hate spam.




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From bruce.griffiths at xtra.co.nz  Thu Oct  2 16:28:56 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Fri, 03 Oct 2008 09:28:56 +1300
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: <E1KlOmJ-0007rp-88@febo.com>
References: <mailman.195.1222952732.2205.time-nuts@febo.com>
	<E1KlOmJ-0007rp-88@febo.com>
Message-ID: <48E52F08.8070400@xtra.co.nz>

Mike Monett wrote:
>   Hello Bruce,
>
>   This is my first attempt to post so I'm not sure if it will work.
>
>   I have been researching the forum archive and find it is by  far the
>   best resource  on time and frequency available anywhere.  Also, your
>   posts are extremely helpful to a newcomer. Thanks!
>
>   I am  curious  about  the  NIST   GPS  timing  receiver  that  has a
>   resolution of a few ps. It doesn't seem possible to get that kind of
>   precision with conventional GPS methods that produce a 1pps signal.
>
>   Can you  describe  more how this is done, and do  you  have  any web
>   links that give more information?
>
>   Thanks,
>
>   Mike Monett
>
>   
Mike

They actually use an augmented form of GPS common view for which the GPS 
PPS signal and its timing variations are largely common to both 
locations and thus largely cancel when comparing the frequencies at the 
customer site with the standards at NIST.
With a good timing receiver (and antenna location) the sawtooth 
corrected PPS signal timing noise can be as low as a few nanosec.
The "all in view" technique will reduce the noise contribution to the 
comparison somewhat.

The timestamp resolution of better than 30ps or so ensures that time 
stamp quantisation noise is negligible.
It also allows, in principle at least, standalone 3 cornered hat 
comparisons of the frequency instabilities of the 3 sources connected to 
the customer instrument.

For more detail see:
http://tf.nist.gov/timefreq/service/fms.htm

Only carrier phase GPS techniques are potentially capable of picosecond 
noise levels.
However there are a large number of effects that have to be taken into 
account and data reduction and correction is very complex.

Bruce


From bruce.griffiths at xtra.co.nz  Thu Oct  2 16:41:18 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Fri, 03 Oct 2008 09:41:18 +1300
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: <000301c924c7$26073c30$0300a8c0@pc52>
References: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>
	<000301c924c7$26073c30$0300a8c0@pc52>
Message-ID: <48E531EE.5090505@xtra.co.nz>

Tom Van Baak wrote:
>> I'm wondering about the possibility of checking the frequency of my
>> oscillator by using a NTP synced RT Linux system. What I'm thinking of
>>     
>
> An "all-PC" frequency counter is a great idea. True, the
> performance is limited compared to GPS time sources and
> hardware frequency counters, but there's something to be
> said for an all (or almost all) software approach.
>
> Time-stamping from an external pin transition should work fine.
>
> Consider also using the sound card as a time comparator.
> If you put your divided down UUT the left channel and an
> NTP sync'd parallel or serial port tick into the right channel
> you can compare the relative phase by looking at the stereo
> input data. Phase change over time gives you frequency error.
>
> The instability of the sound card's own LO drops out of the
> equation. With 44.1 kHz sampling you could handle tick rates
> of 1 kHz without any problem. This should be quite a bit more
> accurate than 1 Hz sampling, so you might have to wait less
> for your goal of 1 ppm resolution. If the limiting factor is the
> quality of your NTP connection, then you've done a good job.
>
> /tvb
>
>
>   
Tom

When using a sound card for frequency comparisons the zero crossing time 
stamp resolution is improved if the slew rate of the input signal is 
slow enough that several (3 or more) samples are taken in the vicinity 
of the zero crossing. One can then make use of  WKS (Whittaker, 
Kotelnikov, Shannon) interpolation to accurately calculate a high 
resolution zero crossing time stamp.
The instability of the sound card LO isnt completely cancelled if the 
zero crossings of the the 2 signals aren't coincident.

Bruce



From tvb at LeapSecond.com  Thu Oct  2 17:09:34 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Thu, 2 Oct 2008 14:09:34 -0700
Subject: [time-nuts] Testing frequency using NTP
References: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>
	<000301c924c7$26073c30$0300a8c0@pc52> <48E531EE.5090505@xtra.co.nz>
Message-ID: <000c01c924d3$2c9e21b0$0300a8c0@pc52>

> When using a sound card for frequency comparisons the zero crossing time 
> stamp resolution is improved if the slew rate of the input signal is 
> slow enough that several (3 or more) samples are taken in the vicinity 
> of the zero crossing. One can then make use of  WKS (Whittaker, 
> Kotelnikov, Shannon) interpolation to accurately calculate a high 
> resolution zero crossing time stamp.

Clever.

> The instability of the sound card LO isnt completely cancelled if the 
> zero crossings of the the 2 signals aren't coincident.

That seems right for absolute event timing with a stereo sound card
but I think for a frequency measurement the delay, if any, between
channels would also cancel out (as long as the delay itself stays
relatively fixed). We'll know for sure when someone actually tries it.

A sound card timing experiment, vaguely related to this, is here:
http://www.leapsecond.com/pages/sound-1pps/

There I used a sound card to generate a 1 PPS and measured its
ADEV. Note that this is unrelated to NTP (NTP disciplines the CPU
or system bus clock, which is typically not the same oscillator as
the sound card clock).

Win32 source code: http://www.leapsecond.com/tools/1hz.c

/tvb
http://www.LeapSecond.com




From cfharris at erols.com  Thu Oct  2 17:18:24 2008
From: cfharris at erols.com (Chuck Harris)
Date: Thu, 02 Oct 2008 17:18:24 -0400
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <ECE7A93BD093E1439C20020FBE87C47FEB52281F25@ALTPHYEMBEVSP20.RES.AD.JPL>
References: <728480.33864.qm@web35405.mail.mud.yahoo.com>	<40777.59990.qm@web35406.mail.mud.yahoo.com>	<34144257F8BF4D59B25BE9A5B0248FAD@APOLLO>
	<ECE7A93BD093E1439C20020FBE87C47FEB52281F25@ALTPHYEMBEVSP20.RES.AD.JPL>
Message-ID: <48E53AA0.6030700@erols.com>

Lux, James P wrote:

> In the U.S., depending on where the installation is (residential vs industrial), the neutral ("groundED conductor")
> is bonded (code-speak for permanently connected) to the earth ground at the service entrance panel. The safety ground
> ("groundING conductor" aka green-wire ground) runs separately from that point.

That is true on 120V 15 or 20A circuits, whether you are industrial,
or residential.

> If you have a 15A receptacle (NEMA 5-15R, for instance), there is a rule about which slot connects to neutral and
> which to line (wider is closer to earth ground, e.g. neutral).  And, on screw in light fixtures, the neutral must be
> connected to the shell (so that if some of the male thread is exposed, it's at lower voltage relative to the grounded
> fixture.
> 
> There are lots of configurations possible (including, for instance, balanced 120V, where each side is 60V relative to
> earth ground) still using the NEMA 5-15R configuration.

To the best of my knowledge, that configuration is only found in marine applications.
NEC doesn't allow it on shore.

> And, there's a lot of stuff when you're running off an isolated power source (e.g. a generator or UPS).
> 
> And, if you're in an industrial or office environment, fed with 3 phase power, there's all kinds of strange
> configurations possible (e.g. delta, with the midpoint of one phase winding grounded, or Wye/Star with the neutral
> bonded through a high impedance to ground).

True, but they all end up the same as the residential 120V circuit, with the
black wire hot, and the white (or grey) neutral bonded to the service panel.

-Chuck Harris



From bruce.griffiths at xtra.co.nz  Thu Oct  2 17:29:21 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Fri, 03 Oct 2008 10:29:21 +1300
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: <000c01c924d3$2c9e21b0$0300a8c0@pc52>
References: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>	<000301c924c7$26073c30$0300a8c0@pc52>
	<48E531EE.5090505@xtra.co.nz> <000c01c924d3$2c9e21b0$0300a8c0@pc52>
Message-ID: <48E53D31.8090706@xtra.co.nz>

Tom Van Baak wrote:
>> When using a sound card for frequency comparisons the zero crossing time 
>> stamp resolution is improved if the slew rate of the input signal is 
>> slow enough that several (3 or more) samples are taken in the vicinity 
>> of the zero crossing. One can then make use of  WKS (Whittaker, 
>> Kotelnikov, Shannon) interpolation to accurately calculate a high 
>> resolution zero crossing time stamp.
>>     
>
> Clever.
>
>   
>> The instability of the sound card LO isnt completely cancelled if the 
>> zero crossings of the the 2 signals aren't coincident.
>>     
>
> That seems right for absolute event timing with a stereo sound card
> but I think for a frequency measurement the delay, if any, between
> channels would also cancel out (as long as the delay itself stays
> relatively fixed). We'll know for sure when someone actually tries it.
>
> A sound card timing experiment, vaguely related to this, is here:
> http://www.leapsecond.com/pages/sound-1pps/
>
> There I used a sound card to generate a 1 PPS and measured its
> ADEV. Note that this is unrelated to NTP (NTP disciplines the CPU
> or system bus clock, which is typically not the same oscillator as
> the sound card clock).
>
> Win32 source code: http://www.leapsecond.com/tools/1hz.c
>
> /tvb
> http://www.LeapSecond.com
>
>   

Tom

The short term phase instabilities of the sound card LO that occur 
during the finite interval between the zero crossing times for one 
channel and the zero crossing time for the other channel can be 
significant. Also even with a zero noise sound card LO the 2 zero 
crossings occur at different times so that some correction for the 
additional phase instability of the 2 sources over this time interval is 
needed in exactly the same way as for a dual mixer time difference 
system when the 2 zero crossings aren't nearly coincident in time.
Such variations are substantially reduced when the input frequencies are 
increased.

If the input signal SNR is sufficiently high the zero crossing time 
stamp jitter noise may be as low as a few ns for a 1khz input frequency.

Bruce


From phk at phk.freebsd.dk  Thu Oct  2 17:31:55 2008
From: phk at phk.freebsd.dk (Poul-Henning Kamp)
Date: Thu, 02 Oct 2008 21:31:55 +0000
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: Your message of "Thu, 02 Oct 2008 12:43:28 MST."
	<000301c924c7$26073c30$0300a8c0@pc52> 
Message-ID: <1774.1222983115@critter.freebsd.dk>

In message <000301c924c7$26073c30$0300a8c0 at pc52>, "Tom Van Baak" writes:
>> I'm wondering about the possibility of checking the frequency of my
>> oscillator by using a NTP synced RT Linux system. What I'm thinking of
>
>An "all-PC" frequency counter is a great idea. 

Actually, the best hardware for the job is the Soekris NET4501
which can timestamp a signal to a quarter microsecond.

That's why we use it for NTP servers in the first place.

All the software you need is in the FreeBSD kernel, and there
is a handy userland program to get the measurments into ascii
format (the earlier mentioned ppsapitest program).

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.


From bruce.griffiths at xtra.co.nz  Thu Oct  2 17:59:21 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Fri, 03 Oct 2008 10:59:21 +1300
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: <000c01c924d3$2c9e21b0$0300a8c0@pc52>
References: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>	<000301c924c7$26073c30$0300a8c0@pc52>
	<48E531EE.5090505@xtra.co.nz> <000c01c924d3$2c9e21b0$0300a8c0@pc52>
Message-ID: <48E54439.8030001@xtra.co.nz>

Tom Van Baak wrote:
>> The instability of the sound card LO isnt completely cancelled if the 
>> zero crossings of the the 2 signals aren't coincident.
>>     
>
> That seems right for absolute event timing with a stereo sound card
> but I think for a frequency measurement the delay, if any, between
> channels would also cancel out (as long as the delay itself stays
> relatively fixed). We'll know for sure when someone actually tries it.
>
> A sound card timing experiment, vaguely related to this, is here:
> http://www.leapsecond.com/pages/sound-1pps/
>
> There I used a sound card to generate a 1 PPS and measured its
> ADEV. Note that this is unrelated to NTP (NTP disciplines the CPU
> or system bus clock, which is typically not the same oscillator as
> the sound card clock).
>
> Win32 source code: http://www.leapsecond.com/tools/1hz.c
>
> /tvb
> http://www.LeapSecond.com
>   
Tom

With  a high end sound card one can lock the LO to a synthesized SPDIF 
source with a stable frequency reference which should minimise long term 
sound card LO frequency variations when these are significant.

The major source of interchannel phase shift instability will be the 
phase shift instabilities of the sound card input RC coupling network 
particularly if electrolytic capacitors are used and the input 
frequencies are too close to the high pass RC filter 3dB frequency. 
Amplifier phase shift instabilities are much smaller and the 
interchannel group delay mismatch will be relatively small as the group 
delay for each channel is determined by the digital filters used by the ADC.

With a high end (24 bit) sound card it is relatively easy to achieve a 
measurement noise comparable to that of the traditional zero crossing 
detector used in a dual mixer sytem.

Bruce



From wje at quackers.net  Thu Oct  2 18:09:21 2008
From: wje at quackers.net (wje)
Date: Thu, 02 Oct 2008 18:09:21 -0400
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <012801c924c2$68352ae0$0300000a@cookie>
References: <953814.52042.qm@web35402.mail.mud.yahoo.com>
	<012801c924c2$68352ae0$0300000a@cookie>
Message-ID: <48E54691.7030107@quackers.net>

   And this is another reason you should pay attention to hot and neutral.
   The hot side is usually where the fuse is, as is the case in the 5061.
   If you swap them, you no longer have any protection against an internal
   hot-to-ground AC fault.
Bill Ezell
----------
They said 'Windows or better'
so I used Linux.

   Ian Sheffield wrote:

Similar to what another poster suggested, but more direct -
assuming the schematic shows that only the live side is fuse protected
inside the HP, then if you take out the fuse
on the rear panel, and see which prong on the connector connects to it, that
should tell you.

 - unless both sides are fused :-(

Ian.

----- Original Message -----
From: "Jeffrey Okamitsu" [1]<w3kl at w3kl.com>
To: "Discussion of precise time and frequency measurement"
[2]<time-nuts at febo.com>
Sent: Thursday, October 02, 2008 7:56 PM
Subject: Re: [time-nuts] AC Connector On HP 5061B


"What happens to a 5061 if I swap the power wires? I can imagine some second
order considerations that would depend on how the power transformer is
constructed."

This is my concern. Hence, I want to get it right in the beginning.

Jeff


Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

--- On Thu, 10/2/08, Hal Murray [3]<hmurray at megapathdsl.net> wrote:

From: Hal Murray [4]<hmurray at megapathdsl.net>
Subject: Re: [time-nuts] AC Connector On HP 5061B
To: "Discussion of precise time and frequency measurement"
[5]<time-nuts at febo.com>
Date: Thursday, October 2, 2008, 1:56 PM


US is similar regarding the lashing together of earth and ground for
single phase power. However, current US electric code is very specific
about which terminal of the AC plug is wired to "hot" and which

is

wired to "neutral".

It used to matter back in the tube days when cheap radios/TVs didn't have a

power transformer.  The neutral was connected to the chassis and the B+ was
derived from the hot line.  That gives you a hot chassis if you swap the
power wires.  (The chassis was all hidden in plastic, at least in theory.)


What happens to a 5061 if I swap the power wires?  I can imagine some second
order considerations that would depend on how the power transformer is
constructed.

References

   1. mailto:w3kl at w3kl.com
   2. mailto:time-nuts at febo.com
   3. mailto:hmurray at megapathdsl.net
   4. mailto:hmurray at megapathdsl.net
   5. mailto:time-nuts at febo.com

From james.p.lux at jpl.nasa.gov  Thu Oct  2 19:27:04 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Thu, 2 Oct 2008 16:27:04 -0700
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <48E53AA0.6030700@erols.com>
References: <728480.33864.qm@web35405.mail.mud.yahoo.com>
	<40777.59990.qm@web35406.mail.mud.yahoo.com>
	<34144257F8BF4D59B25BE9A5B0248FAD@APOLLO>
	<ECE7A93BD093E1439C20020FBE87C47FEB52281F25@ALTPHYEMBEVSP20.RES.AD.JPL>
	<48E53AA0.6030700@erols.com>
Message-ID: <ECE7A93BD093E1439C20020FBE87C47FEB52281F36@ALTPHYEMBEVSP20.RES.AD.JPL>

>
> Lux, James P wrote:
>
> > In the U.S., depending on where the installation is (residential vs
> > industrial), the neutral ("groundED conductor") is bonded
> (code-speak
> > for permanently connected) to the earth ground at the
> service entrance panel. The safety ground ("groundING
> conductor" aka green-wire ground) runs separately from that point.
>
> That is true on 120V 15 or 20A circuits, whether you are
> industrial, or residential.

One can have isolated circuits that have no connection (i.e. no "grounded conductor") (used for systems where there are humans connected to test equipment, for instance) and there's that high impedance bonding thing in industrial applications (although I think that ONLY applies to 3 phase loads..don't have the code here in front of me to check.)

>
> > If you have a 15A receptacle (NEMA 5-15R, for instance), there is a
> > rule about which slot connects to neutral and which to line
> (wider is
> > closer to earth ground, e.g. neutral).  And, on screw in light
> > fixtures, the neutral must be connected to the shell (so
> that if some of the male thread is exposed, it's at lower
> voltage relative to the grounded fixture.
> >
> > There are lots of configurations possible (including, for instance,
> > balanced 120V, where each side is 60V relative to earth
> ground) still using the NEMA 5-15R configuration.
>
> To the best of my knowledge, that configuration is only found
> in marine applications.
> NEC doesn't allow it on shore.

Actually, it does allow it (art 647, I think). It's used in recording studios, for instance (old NEC art 530). There's some wording about use under supervision of qualified personnel, but if you're smart enough to hook up balanced AC power for your rack of oscillators, you're probably qualified to use it.  Just don't do it to wire your whole house that way. Might have to do some careful talking if it comes up.. But your time-nuts lab is probably an industrial occupancy, eh?

Of course, if the thing is all contained within a big cabinet or rack, and you're not wiring up wall sockets, then the whole rack is the "utilization equipment" and what's inside doesn't necessarily have to follow NEC.

>
> > And, there's a lot of stuff when you're running off an
> isolated power source (e.g. a generator or UPS).
> >
> > And, if you're in an industrial or office environment, fed with 3
> > phase power, there's all kinds of strange configurations possible
> > (e.g. delta, with the midpoint of one phase winding
> grounded, or Wye/Star with the neutral bonded through a high
> impedance to ground).
>
> True, but they all end up the same as the residential 120V
> circuit, with the black wire hot, and the white (or grey)
> neutral bonded to the service panel.

Delta with midpoint ground might not even have a neutral, even though it's a separately derived "grounded system". You'd have a 240V receptacle with 2 hots and a ground. I'm not sure if you could legally put a single phase receptacle between the high phase and one of the two low phases.
But true if it's a 120V circuit.. The midpoint would be the neutral.


From tvb at LeapSecond.com  Thu Oct  2 20:32:10 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Thu, 2 Oct 2008 17:32:10 -0700
Subject: [time-nuts] Testing frequency using NTP
References: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>	<000301c924c7$26073c30$0300a8c0@pc52>
	<48E531EE.5090505@xtra.co.nz> <000c01c924d3$2c9e21b0$0300a8c0@pc52>
	<48E53D31.8090706@xtra.co.nz>
Message-ID: <002701c924ef$7c755de0$0300a8c0@pc52>

> Tom
> 
> The short term phase instabilities of the sound card LO that occur 
> during the finite interval between the zero crossing times for one 
> channel and the zero crossing time for the other channel can be 
> significant.
> ...

Bruce,

I'm all ears for details about the phase stability of sounds cards.
But you need to define "significant" here. Give me real numbers
and I'll believe it.

Bear in mind that we're talking about a PC-based application with
a couple of milliseconds of expected NTP time jitter, and a modest
goal of measuring frequency to ppm levels even if it takes hours
to achieve that level.

/tvb



From sar10538 at gmail.com  Thu Oct  2 20:41:52 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Fri, 3 Oct 2008 13:41:52 +1300
Subject: [time-nuts] And, for my next trick, 50Hz
Message-ID: <1231b6a80810021741i64d779bj13948680658be749@mail.gmail.com>

Call me crazy but I wonder if my accurate relative period of time
could be derived from the 230VAC 50Hz mains supply over here. Now,
before you yell at me, consider this, I have a couple of mains driven
clocks in the house and only seem to need to change the time on them
when we go from Standard Time to Daylight Saving Time. Agreed, the
instantaneous frequency of the mains is not always spot on but the
long term average seems to be kept pretty accurate or we would all
have to keep changing our mains timed clocks. If I knew the standard
deviation of the mains, I could probably calculate the period of time
I'd have to gate my breadboard "frequency counter" to achieve a
certain accuracy.

73, Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From tvb at LeapSecond.com  Thu Oct  2 20:52:26 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Thu, 2 Oct 2008 17:52:26 -0700
Subject: [time-nuts] And, for my next trick, 50Hz
References: <1231b6a80810021741i64d779bj13948680658be749@mail.gmail.com>
Message-ID: <001301c924f2$511ed330$0300a8c0@pc52>

> Call me crazy but I wonder if my accurate relative period of time
> could be derived from the 230VAC 50Hz mains supply over here. Now,
> before you yell at me, consider this, I have a couple of mains driven
> clocks in the house and only seem to need to change the time on them
> when we go from Standard Time to Daylight Saving Time. Agreed, the
> instantaneous frequency of the mains is not always spot on but the
> long term average seems to be kept pretty accurate or we would all
> have to keep changing our mains timed clocks. If I knew the standard
> deviation of the mains, I could probably calculate the period of time
> I'd have to gate my breadboard "frequency counter" to achieve a
> certain accuracy.
> 
> 73, Steve

For standard (or Allan) deviation of mains frequencies, see:

<Accuracy and stability of the 50 Hz mains frequency>
http://wwwhome.cs.utwente.nl/~ptdeboer/misc/mains.html

<60 Hz AC Mains Frequency Accuracy Measurement>
http://www.leapsecond.com/pages/mains/

/tvb



From dforbes at dakotacom.net  Thu Oct  2 21:14:18 2008
From: dforbes at dakotacom.net (David Forbes)
Date: Thu, 2 Oct 2008 18:14:18 -0700
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: <002701c924ef$7c755de0$0300a8c0@pc52>
References: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>
	<000301c924c7$26073c30$0300a8c0@pc52>	<48E531EE.5090505@xtra.co.nz>
	<000c01c924d3$2c9e21b0$0300a8c0@pc52>	<48E53D31.8090706@xtra.co.nz>
	<002701c924ef$7c755de0$0300a8c0@pc52>
Message-ID: <a06240506c50b1f94e273@[192.168.0.24]>

At 5:32 PM -0700 10/2/08, Tom Van Baak wrote:
>>  Tom
>>
>>  The short term phase instabilities of the sound card LO that occur
>>  during the finite interval between the zero crossing times for one
>>  channel and the zero crossing time for the other channel can be
>>  significant.
>>  ...
>
>Bruce,
>
>I'm all ears for details about the phase stability of sounds cards.
>But you need to define "significant" here. Give me real numbers
>and I'll believe it.
>
>Bear in mind that we're talking about a PC-based application with
>a couple of milliseconds of expected NTP time jitter, and a modest
>goal of measuring frequency to ppm levels even if it takes hours
>to achieve that level.
>
>/tvb

Tom,

I expect that the answer is highly dependent on what sort of PLL they 
use on the sound card to generate the sampling clock from the 
oscillator. PLLs used on digital cards can be very lousy with regard 
to jitter.

I remember designing a VMEbus card about 10 years ago that used a 
little 20-pin IC Works PLL chip to double the clock. When I looked 
closely, I saw that that chip was responsible for generating a 
nanosecond of jitter on a 66 MHz clock. That is one crappy PLL!

But a nanosecond is much smaller than the millisecond NTP jitter, so 
you'd have to compare the sound card's clock jitter to that of the 
NTP server averaged over millions of 1 KHz clock input edges to see 
the effects of the PLL.

A sound card that uses a directly divided crystal oscillator, if such 
things exist, should be several orders of magnitude better.

Curiously, the icworks.com domain name is now available for purchase.
-- 

--David Forbes, Tucson, AZ
http://www.cathodecorner.com/


From bruce.griffiths at xtra.co.nz  Thu Oct  2 21:34:28 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Fri, 03 Oct 2008 14:34:28 +1300
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: <002701c924ef$7c755de0$0300a8c0@pc52>
References: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>	<000301c924c7$26073c30$0300a8c0@pc52>	<48E531EE.5090505@xtra.co.nz>
	<000c01c924d3$2c9e21b0$0300a8c0@pc52>	<48E53D31.8090706@xtra.co.nz>
	<002701c924ef$7c755de0$0300a8c0@pc52>
Message-ID: <48E576A4.7000309@xtra.co.nz>

Tom Van Baak wrote:
>> Tom
>>
>> The short term phase instabilities of the sound card LO that occur 
>> during the finite interval between the zero crossing times for one 
>> channel and the zero crossing time for the other channel can be 
>> significant.
>> ...
>>     
>
> Bruce,
>
> I'm all ears for details about the phase stability of sounds cards.
> But you need to define "significant" here. Give me real numbers
> and I'll believe it.
>
> Bear in mind that we're talking about a PC-based application with
> a couple of milliseconds of expected NTP time jitter, and a modest
> goal of measuring frequency to ppm levels even if it takes hours
> to achieve that level.
>
> /tvb
>
>   
Tom

When compared to a few milliseconds of NTP jitter the phase instability 
of a sound card LO is usually insignificant, particularly if it is 
sampling at a frequency directly derived from a crystal oscillator via 
division either explicit or implicit.

For the more demanding task of comparing a couple of reasonably stable 
sources such phase instabilities appear to be relatively small 
(subnanosecond with a high end card).
The simplest way to evaluate this for a particular sound card is to 
divide down the output of a low noise OCXO, low pass filter the 
resultant signal and drive both sound card channels with the same signal.

A stable phase shift between the channels can be produced by driving the 
L and R channels in antiphase.
The simplest way to do this with a stable phase shift between the 2 
signals, at least with a quasi sinusoidal signal, is to use an audio 
transformer with a centre tapped secondary.
With a high end sound card that has balanced inputs it is even simpler 
to drive the 2 channels 180 degrees out of phase.
This allows the measurement noise to be evaluated as a function of the 
time interval between the zero crossings for each channel by varying the 
signal frequency.
To minimise the contribution from sound card input noise (or at least 
maintain this constant) the signal transition times should remain fixed 
as the signal frequency is varied.
It is also essential to use a low phase noise signal or the signal phase 
instability for an averaging time of 1/2 the signal period will dominate.

With an input signal having a finite slew rate at the zero crossing 
sound card noise will produce zero crossing time stamp jitter that 
exceeds any contribution from the LO.
For example, a full scale 1 kHz input signal will have a zero crossing 
time stamp jitter of 1.6ns if the sound card rms noise is 10ppm of full 
scale.
Only a few sound cards are this quiet.
This can be reduced by digital filtering which lowers the effective 
bandwidth.
This isn't so different from the low pass filtering of the mixer IF 
output used in classical dual mixer time difference systems or in such 
instruments as the TS5120A.

It would be useful if the phase stability data for different sound cards 
could be obtained.
I only have a relatively high end card with balanced inputs except for 
motherboard sound systems most of which appear to be rather noisy - lots 
of extraneous signals present in the ADC output spectrum.

Bruce


From w3kl at w3kl.com  Thu Oct  2 22:01:38 2008
From: w3kl at w3kl.com (Jeffrey Okamitsu)
Date: Thu, 2 Oct 2008 19:01:38 -0700 (PDT)
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <48E54691.7030107@quackers.net>
Message-ID: <435424.38503.qm@web35407.mail.mud.yahoo.com>

Good point.
?
BTW.? I confirmed the schematic - B is "hot", A is "neutral".
?
Jeff

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

--- On Thu, 10/2/08, wje <wje at quackers.net> wrote:

From: wje <wje at quackers.net>
Subject: Re: [time-nuts] AC Connector On HP 5061B
To: "Discussion of precise time and frequency measurement" <time-nuts at febo.com>
Date: Thursday, October 2, 2008, 6:09 PM

   And this is another reason you should pay attention to hot and neutral.
   The hot side is usually where the fuse is, as is the case in the 5061.
   If you swap them, you no longer have any protection against an internal
   hot-to-ground AC fault.
Bill Ezell
----------
They said 'Windows or better'
so I used Linux.

   Ian Sheffield wrote:

Similar to what another poster suggested, but more direct -
assuming the schematic shows that only the live side is fuse protected
inside the HP, then if you take out the fuse
on the rear panel, and see which prong on the connector connects to it, that
should tell you.

 - unless both sides are fused :-(

Ian.

----- Original Message -----
From: "Jeffrey Okamitsu" [1]<w3kl at w3kl.com>
To: "Discussion of precise time and frequency measurement"
[2]<time-nuts at febo.com>
Sent: Thursday, October 02, 2008 7:56 PM
Subject: Re: [time-nuts] AC Connector On HP 5061B


"What happens to a 5061 if I swap the power wires? I can imagine some
second
order considerations that would depend on how the power transformer is
constructed."

This is my concern. Hence, I want to get it right in the beginning.

Jeff


Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

--- On Thu, 10/2/08, Hal Murray [3]<hmurray at megapathdsl.net> wrote:

From: Hal Murray [4]<hmurray at megapathdsl.net>
Subject: Re: [time-nuts] AC Connector On HP 5061B
To: "Discussion of precise time and frequency measurement"
[5]<time-nuts at febo.com>
Date: Thursday, October 2, 2008, 1:56 PM


US is similar regarding the lashing together of earth and ground for
single phase power. However, current US electric code is very specific
about which terminal of the AC plug is wired to "hot" and which

is

wired to "neutral".

It used to matter back in the tube days when cheap radios/TVs didn't have a

power transformer.  The neutral was connected to the chassis and the B+ was
derived from the hot line.  That gives you a hot chassis if you swap the
power wires.  (The chassis was all hidden in plastic, at least in theory.)


What happens to a 5061 if I swap the power wires?  I can imagine some second
order considerations that would depend on how the power transformer is
constructed.

References

   1. mailto:w3kl at w3kl.com
   2. mailto:time-nuts at febo.com
   3. mailto:hmurray at megapathdsl.net
   4. mailto:hmurray at megapathdsl.net
   5. mailto:time-nuts at febo.com
_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

From bruce.griffiths at xtra.co.nz  Thu Oct  2 22:09:03 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Fri, 03 Oct 2008 15:09:03 +1300
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: <48E54439.8030001@xtra.co.nz>
References: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>	<000301c924c7$26073c30$0300a8c0@pc52>	<48E531EE.5090505@xtra.co.nz>
	<000c01c924d3$2c9e21b0$0300a8c0@pc52> <48E54439.8030001@xtra.co.nz>
Message-ID: <48E57EBF.7050503@xtra.co.nz>


> Tom
>
>
> The major source of interchannel phase shift instability will be the 
> phase shift instabilities of the sound card input RC coupling network 
> particularly if electrolytic capacitors are used and the input 
> frequencies are too close to the high pass RC filter 3dB frequency. 
> Amplifier phase shift instabilities are much smaller and the 
> interchannel group delay mismatch will be relatively small as the group 
> delay for each channel is determined by the digital filters used by the ADC.
>
>   
For temperatures around 20C a wet electrolytic cap has a tempco of aroun 
+500ppm/C or so.
With a 0.5dBinput frequency of 20Hz a typical sound card has a high pass 
filter input time constant of about 33ms.
At 1kHz the corresponding phase shift is about 800ns with a tempco of 
about 0.4ns/C.

Bruce


From bruce.griffiths at xtra.co.nz  Thu Oct  2 22:37:52 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Fri, 03 Oct 2008 15:37:52 +1300
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: <48E57EBF.7050503@xtra.co.nz>
References: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>	<000301c924c7$26073c30$0300a8c0@pc52>	<48E531EE.5090505@xtra.co.nz>	<000c01c924d3$2c9e21b0$0300a8c0@pc52>
	<48E54439.8030001@xtra.co.nz> <48E57EBF.7050503@xtra.co.nz>
Message-ID: <48E58580.30205@xtra.co.nz>

Bruce Griffiths wrote:
>> Tom
>>
>>
>> The major source of interchannel phase shift instability will be the 
>> phase shift instabilities of the sound card input RC coupling network 
>> particularly if electrolytic capacitors are used and the input 
>> frequencies are too close to the high pass RC filter 3dB frequency. 
>> Amplifier phase shift instabilities are much smaller and the 
>> interchannel group delay mismatch will be relatively small as the group 
>> delay for each channel is determined by the digital filters used by the ADC.
>>
>>   
>>     
> For temperatures around 20C a wet electrolytic cap has a tempco of aroun 
> +500ppm/C or so.
> With a 0.5dBinput frequency of 20Hz a typical sound card has a high pass 
> filter input time constant of about 33ms.
> At 1kHz the corresponding phase shift is about 800ns with a tempco of 
> about 0.4ns/C.
>
> Bruce
>   
Correction:
The time constant should have been 22ms and the phase shift 1.16us with 
a tempco of 580ps/C.
Since both channels have the same nominal low frequency cutoff the 
differential phase shift tempco will be somewhat smaller.

Bruce



From didier at cox.net  Thu Oct  2 22:43:55 2008
From: didier at cox.net (Didier Juges)
Date: Thu, 2 Oct 2008 21:43:55 -0500
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <1231b6a80810021202h8878c14obc39c2600f1996c4@mail.gmail.com>
References: <728480.33864.qm@web35405.mail.mud.yahoo.com><40777.59990.qm@web35406.mail.mud.yahoo.com><34144257F8BF4D59B25BE9A5B0248FAD@APOLLO><48E50EA3.3030001@comcast.net>
	<48E516DA.1000402@pacific.net>
	<1231b6a80810021202h8878c14obc39c2600f1996c4@mail.gmail.com>
Message-ID: <E1553FBD71B04D988080753A7ED7B67F@didierhp>

> -----Original Message-----
> From: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Steve Rooke
> Sent: Thursday, October 02, 2008 2:02 PM
> To: brooke at pacific.net; Discussion of precise time and 
> frequency measurement
> Subject: Re: [time-nuts] AC Connector On HP 5061B
> 
> 2008/10/3 Brooke Clarke <brooke at pacific.net>:
> > It's not clear to me how 230 VAC countries handle that problem?  If 
> > they also use the same transformer but only bring in the 
> 230 VAC then 
> > neither side of the line is near ground potential.
> 
> In 230/240 VAC the neutral side of the transformer output is 
> earthed at the transformer end. So breakdowns in the 
> transformer go direct to earth at the distribution 
> transformer itself. At the customer end you will find a small 
> voltage at the neutral terminal due to the current running 
> down the resistance of the conductor back to the transformer.
> As this is not a balanced supply, outlets have specific 
> connections to each pole of the mains and earth. The earth 
> connection is made locally, usually bonded to the incoming water main.
> 
> 73
> Steve
> --
> Steve Rooke - ZL3TUV & G8KVD
> Omnium finis imminet
> 

In France, power distribution is typically via 3 phase 220/380, so each 220
phase has one side at neutral. I am not sure where it is grounded.  Usually,
the three phases drive separate areas of the house in an attempt to balance
the load. Few houses used to have all electric heating, even though that
trend has increased substantially in the last 20 years. High power consumers
(such as house heating) use the three phase directly (that's the case in my
dad's house.) 

There is no pole-pig in France, each neighborhood has a larger transformer
in a small building at the end of the street feeding a significant number of
houses. Distribution to the transformer is at high voltage (6kV I think, but
I may be off).

Since over 80% of electrical power in France comes from nuclear power
plants, the effect of gas prices on electricity prices has not been very
significant yet.

Didier KO4BB



From sar10538 at gmail.com  Thu Oct  2 23:29:19 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Fri, 3 Oct 2008 16:29:19 +1300
Subject: [time-nuts] And, for my next trick, 50Hz
In-Reply-To: <001301c924f2$511ed330$0300a8c0@pc52>
References: <1231b6a80810021741i64d779bj13948680658be749@mail.gmail.com>
	<001301c924f2$511ed330$0300a8c0@pc52>
Message-ID: <1231b6a80810022029t676bdcb7k1479ef0ad195ee1d@mail.gmail.com>

Hi Tom,

2008/10/3 Tom Van Baak <tvb at leapsecond.com>:

> For standard (or Allan) deviation of mains frequencies, see:
>
> <Accuracy and stability of the 50 Hz mains frequency>
> http://wwwhome.cs.utwente.nl/~ptdeboer/misc/mains.html
>
> <60 Hz AC Mains Frequency Accuracy Measurement>
> http://www.leapsecond.com/pages/mains/

Many thanks for these pointers, very interesting and useful work. This
does show that for a long sampling time, quite a high degree of
accuracy could be obtained. The downsides are that the sampling period
would have to be very long and could easily be affected by power cuts
causing failure to my proposed testing method. So theory proved but
impractical. Looks like I'll have to bite the bullet and go with a GPS
disciplined ocxo to make a good frequency standard.

Cheers,
Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From tvb at LeapSecond.com  Thu Oct  2 23:29:25 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Thu, 2 Oct 2008 20:29:25 -0700
Subject: [time-nuts] Testing frequency using NTP
References: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>	<000301c924c7$26073c30$0300a8c0@pc52>	<48E531EE.5090505@xtra.co.nz>	<000c01c924d3$2c9e21b0$0300a8c0@pc52><48E54439.8030001@xtra.co.nz>
	<48E57EBF.7050503@xtra.co.nz> <48E58580.30205@xtra.co.nz>
Message-ID: <001501c92508$3f672460$0300a8c0@pc52>

> The time constant should have been 22ms and the phase shift 1.16us with 
> a tempco of 580ps/C.
> Since both channels have the same nominal low frequency cutoff the 
> differential phase shift tempco will be somewhat smaller.

Thanks for the calculations. So it's probably safe to say the
differential phase shift stability is many orders of magnitude
less than NTP jitter. Good.

Anyway, I think it would make a fun project to see how well a
typical PC sound card actually does as a 1PPS or LF phase
comparator and frequency counter. I wouldn't expect better
results than a $50 surplus eBay time interval counter, but it
would be interesting to see just how bad or even how good it
might be. There are, after all, many timing applications where
nanosecond and picosecond resolution isn't required.

/tvb



From bruce.griffiths at xtra.co.nz  Thu Oct  2 23:53:57 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Fri, 03 Oct 2008 16:53:57 +1300
Subject: [time-nuts] Testing frequency using NTP
In-Reply-To: <001501c92508$3f672460$0300a8c0@pc52>
References: <1231b6a80810011707q5d4a2295ne757716317fbc807@mail.gmail.com>	<000301c924c7$26073c30$0300a8c0@pc52>	<48E531EE.5090505@xtra.co.nz>	<000c01c924d3$2c9e21b0$0300a8c0@pc52><48E54439.8030001@xtra.co.nz>	<48E57EBF.7050503@xtra.co.nz>
	<48E58580.30205@xtra.co.nz> <001501c92508$3f672460$0300a8c0@pc52>
Message-ID: <48E59755.4070909@xtra.co.nz>

Tom Van Baak wrote:
> Anyway, I think it would make a fun project to see how well a
> typical PC sound card actually does as a 1PPS or LF phase
> comparator and frequency counter. I wouldn't expect better
> results than a $50 surplus eBay time interval counter, but it
> would be interesting to see just how bad or even how good it
> might be. There are, after all, many timing applications where
> nanosecond and picosecond resolution isn't required.
>
> /tvb
>
>   
Tom

If one has a frequency counter with say 100uV rms equivalent input noise 
and a 1V peak 1kHz sinewave input signal the trigger jitter will be 
about 16ns rms.
Some frequency counter trigger circuits will be noisier than this.

Thus a good sound card can be expected to have somewhat lower noise than 
this when comparing 2 ~ 1kHz sinewave signals.

To improve the low frequency trigger noise of a counter a carefully 
designed zero crossing detector is required to drive the counter.
Such a zero crossing detector will be limited to a narrow range of 
frequencies unless the various filter time constants etc can be adjusted 
to optimise the zero crossing detector to suit the input frequency of 
interest.

Thus the performance of a sound card for comparison low frequency 
sinewave signals will exceed that of a $50 or even $10,000 counter 
unless suitable ZCDs are used to drive the counter inputs.

If the signal zero crossing slew rates are large enough a good counter 
may outperform a sound card even with low frequency signals.

Bruce


From tvb at LeapSecond.com  Fri Oct  3 00:21:03 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Thu, 2 Oct 2008 21:21:03 -0700
Subject: [time-nuts] And, for my next trick, 50Hz
References: <1231b6a80810021741i64d779bj13948680658be749@mail.gmail.com>
	<001301c924f2$511ed330$0300a8c0@pc52>
	<1231b6a80810022029t676bdcb7k1479ef0ad195ee1d@mail.gmail.com>
Message-ID: <002401c9250f$76694f40$0300a8c0@pc52>

> Many thanks for these pointers, very interesting and useful work. This
> does show that for a long sampling time, quite a high degree of
> accuracy could be obtained. The downsides are that the sampling period
> would have to be very long and could easily be affected by power cuts
> causing failure to my proposed testing method. So theory proved but
> impractical. Looks like I'll have to bite the bullet and go with a GPS
> disciplined ocxo to make a good frequency standard.
> 
> Cheers,
> Steve

Ah, if you are a time-nut of course you will bite the bullet and
get a GPSDO. But you should also not give up on the PC idea.
If it works it will be a great gift to many people (OK, maybe not
the pico- and nanosecond crowd, but to regular millisecond
kind of folks).

And, I no longer think long sample times are required.

Consider the following. Assume you can get NTP to give you
ms or sub-millisecond accurate time-stamps. Also assume you
divide down your UUT to something like 1 kHz and feed that
into one channel of your sound card (and as Bruce pointed
out, maybe the slower the rise time the better in this case).

Now, collect 16-bits of waveform data at 44.1 kHz. First, note
that it's not exactly 44.100000 kHz -- but over time, as your
circular input buffers fill up, you can use NTP time-stamps to
calculate what the sampling rate precisely was/is.

Then, looking at your highly oversampled waveform data, you
can calculate the phase of your UUT frequency relative to the
now precisely known sound card sampling rate. Over time you
will see the phase drift, which then directly gives you the UUT
frequency error.

So what you end up doing is using the sound card like a high
resolution vernier between NTP timekeeping on the inside and
your UUT on the outside. I bet you a Thunderbolt that you can
measure to 1 ppm within ten seconds.

/tvb
http://www.LeapSecond.com

p.s. For extra credit, tee your UUT into both channels, do twice
the math, and see if you can measure both differential phase,
and differential phase drift between them.



From bruce.griffiths at xtra.co.nz  Fri Oct  3 00:38:25 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Fri, 03 Oct 2008 17:38:25 +1300
Subject: [time-nuts] And, for my next trick, 50Hz
In-Reply-To: <002401c9250f$76694f40$0300a8c0@pc52>
References: <1231b6a80810021741i64d779bj13948680658be749@mail.gmail.com>	<001301c924f2$511ed330$0300a8c0@pc52>	<1231b6a80810022029t676bdcb7k1479ef0ad195ee1d@mail.gmail.com>
	<002401c9250f$76694f40$0300a8c0@pc52>
Message-ID: <48E5A1C1.7090702@xtra.co.nz>

Tom Van Baak wrote:
> measure to 1 ppm within ten seconds.
>
> /tvb
> http://www.LeapSecond.com
>
> p.s. For extra credit, tee your UUT into both channels, do twice
> the math, and see if you can measure both differential phase,
> and differential phase drift between them.
>
>
>   
Tom

A better way may be to drive both sound card input channels in phase 
quadrature with a pair of sinewave signals.
One can then any variations in calculated phase (arctan (L/R)) will be 
due to differences phase variations between the L and R channels and 
variations in the phase shift between the 2 signals.
Since 250us of delay line is somewhat inconvenient, will have high 
attenuation and will be very expensive some other means of generating 
the 2 signals in phase quadrature is required.

Corrections would need to be made for the effect of amplitude and 
quadrature phase errors.

Bruce



From chris.cheney at tesco.net  Fri Oct  3 04:31:29 2008
From: chris.cheney at tesco.net (Chris Cheney)
Date: Fri, 03 Oct 2008 09:31:29 +0100
Subject: [time-nuts] And, for my next trick, 50Hz
In-Reply-To: <1231b6a80810021741i64d779bj13948680658be749@mail.gmail.com>
References: <1231b6a80810021741i64d779bj13948680658be749@mail.gmail.com>
Message-ID: <48E5E671.9736.29558B@chris.cheney.tesco.net>

On 3 Oct 2008 at 13:41, Steve Rooke wrote:

> Call me crazy but I wonder if my accurate relative period of time
> could be derived from the 230VAC 50Hz mains supply over here. Now,
> before you yell at me, consider this, I have a couple of mains driven
> clocks in the house and only seem to need to change the time on them when
> we go from Standard Time to Daylight Saving Time. Agreed, the
> instantaneous frequency of the mains is not always spot on but the long
> term average seems to be kept pretty accurate or we would all have to keep
> changing our mains timed clocks. If I knew the standard deviation of the
> mains, I could probably calculate the period of time I'd have to gate my
> breadboard "frequency counter" to achieve a certain accuracy.

A bit of Googling finds:

Frequency: "a variation not exceeding 1 per cent above or below the 
declared frequency;"
(http://www.statutelaw.gov.uk/content.aspx?LegType=All+Legislation&title=e
lectricity+safety+quality+continuity&searchEnacted=0&extentMatchOnly=0&con
fersPower=0&blanketAmendment=0&sortAlpha=0&TYPE=QS&PageNumber=1&NavFrom=0&
parentActiveTextDocId=1590332&ActiveTextDocId=1590368&filesize=4590 - 
section 27(3)(a))

Electric clock time: "NGET will endeavour (in so far as it is able) to 
control electric clock time to within plus or minus 10 seconds"
(http://www.nationalgrid.com/NR/rdonlyres/4894C7AA-DCD2-4835-9986-
57338C31C86A/9922/BC3_i3r18.pdf - section BC3.4.3)

BTW wrt earthing via the incoming water main - in the UK, plastic pipe is 
commonly used for incoming water mains these days.

73
Chris
G3RSE


From d.seiter at comcast.net  Fri Oct  3 04:43:24 2008
From: d.seiter at comcast.net (d.seiter at comcast.net)
Date: Fri, 03 Oct 2008 08:43:24 +0000
Subject: [time-nuts] Need a simple ID for some gear
Message-ID: <100320080843.26745.48E5DB2C00086EF10000687922007340769D0A9B070A9CD20B@comcast.net>

I don't know a whole bunch about microwave gear, so I need a little help.  I came across a small box in a pile this evening and I don't have a clue what it is.

It's a T construct, with SMAs at both ends of the horizontal.  The vertical end looks like it's terminated to gnd.  Internal construction in a plate which connects all three terminals.  Above and below the plate is a ceramic triangle with a circular black insert.  Each plate of the outer case has a circular magnet the same size as the black insert on the ceramic plates, on the external side, and there is a U shaped steel clamp which covers the entire assembly.  

This is probably a really easy question for some of you out there....what is it?

I also came across some K&L filters from my time at Cylink, but the website gave me no joy.  When the sample says S/N 1, I don't expect much...  I suppose I could just feed a signal through them and see where the outputs occur....  both series have 5787.5 embedded n the part number, so I'm thinking that's the center or cutoff frequency.

-Dave


From t_list_1_only at braw.co.uk  Fri Oct  3 04:57:01 2008
From: t_list_1_only at braw.co.uk (David )
Date: Fri, 3 Oct 2008 09:57:01 +0100
Subject: [time-nuts] Need a simple ID for some gear
In-Reply-To: <mailman.224.1223023415.2205.time-nuts@febo.com>
Message-ID: <E5D457BB0D9E41CE971CC66EE297C5C0@sun02h26m>


> I don't know a whole bunch about microwave gear, so I need a 
> little help.  I came across a small box in a pile this 
> evening and I don't have a clue what it is.
> 
> It's a T construct, with SMAs at both ends of the horizontal. 
>  The vertical end looks like it's terminated to gnd.  
> Internal construction in a plate which connects all three 
> terminals.  Above and below the plate is a ceramic triangle 
> with a circular black insert.  Each plate of the outer case 
> has a circular magnet the same size as the black insert on 
> the ceramic plates, on the external side, and there is a U 
> shaped steel clamp which covers the entire assembly.  
> 
> This is probably a really easy question for some of you out 
> there....what is it?


Opening guess- a microwave isolator, the third port being a 50 ohm load
rather than a short to ground? 
http://en.wikipedia.org/wiki/Circulator
Problem is they tend to be relatively narrow band (say 5%) so I have an
expanding junk box that never quite has the one that would be useful !

Cheers




From stanw1le at verizon.net  Fri Oct  3 09:08:33 2008
From: stanw1le at verizon.net (Stan W1LE)
Date: Fri, 03 Oct 2008 09:08:33 -0400
Subject: [time-nuts] Need a simple ID for some gear
In-Reply-To: <100320080843.26745.48E5DB2C00086EF10000687922007340769D0A9B070A9CD20B@comcast.net>
References: <100320080843.26745.48E5DB2C00086EF10000687922007340769D0A9B070A9CD20B@comcast.net>
Message-ID: <48E61951.3000102@verizon.net>

Sounds like a isolator, a passive ferrite device.

Stan, W1LE    Cape Cod


d.seiter at comcast.net wrote:
> I don't know a whole bunch about microwave gear, so I need a little help.  I came across a small box in a pile this evening and I don't have a clue what it is.
>
> It's a T construct, with SMAs at both ends of the horizontal.  The vertical end looks like it's terminated to gnd.  Internal construction in a plate which connects all three terminals.  Above and below the plate is a ceramic triangle with a circular black insert.  Each plate of the outer case has a circular magnet the same size as the black insert on the ceramic plates, on the external side, and there is a U shaped steel clamp which covers the entire assembly.  
>
> This is probably a really easy question for some of you out there....what is it?
>
> I also came across some K&L filters from my time at Cylink, but the website gave me no joy.  When the sample says S/N 1, I don't expect much...  I suppose I could just feed a signal through them and see where the outputs occur....  both series have 5787.5 embedded n the part number, so I'm thinking that's the center or cutoff frequency.
>
> -Dave
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>   



From james.p.lux at jpl.nasa.gov  Fri Oct  3 09:19:29 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Fri, 3 Oct 2008 06:19:29 -0700
Subject: [time-nuts] Need a simple ID for some gear
In-Reply-To: <100320080843.26745.48E5DB2C00086EF10000687922007340769D0A9B070A9CD20B@comcast.net>
Message-ID: <C50B69F1.1639%James.P.Lux@jpl.nasa.gov>

Ferrite circulator.
Black insert is ferrite
If one of the three ports is terminated, it?s hooked up as an isolator.

Jim


On 10/3/08 1:43 AM, "d.seiter at comcast.net" <d.seiter at comcast.net> wrote:

> I don't know a whole bunch about microwave gear, so I need a little help.  I
> came across a small box in a pile this evening and I don't have a clue what it
> is.
>
> It's a T construct, with SMAs at both ends of the horizontal.  The vertical
> end looks like it's terminated to gnd.  Internal construction in a plate which
> connects all three terminals.  Above and below the plate is a ceramic triangle
> with a circular black insert.  Each plate of the outer case has a circular
> magnet the same size as the black insert on the ceramic plates, on the
> external side, and there is a U shaped steel clamp which covers the entire
> assembly.
>
> This is probably a really easy question for some of you out there....what is
> it?
>
> I also came across some K&L filters from my time at Cylink, but the website
> gave me no joy.  When the sample says S/N 1, I don't expect much...  I suppose
> I could just feed a signal through them and see where the outputs occur....
> both series have 5787.5 embedded n the part number, so I'm thinking that's the
> center or cutoff frequency.
>



From scmcgrath at gmail.com  Fri Oct  3 10:02:49 2008
From: scmcgrath at gmail.com (Scott McGrath)
Date: Fri, 3 Oct 2008 10:02:49 -0400
Subject: [time-nuts] Noisy output on Austron 2100T
Message-ID: <c9ffea950810030702s176e55b5y43a5dfb2f64e742d@mail.gmail.com>

My Austron 2100T outputs have significant noise on the peaks of pulses
and square wave output,    Is this normal or is this a fault I need to
correct other than that it works quite nicely and I am usually locked
to Nantucket MA or Seneca NY if Nantucket is out of service

Thanks Scott N1JIN


From scmcgrath at gmail.com  Fri Oct  3 10:09:02 2008
From: scmcgrath at gmail.com (Scott McGrath)
Date: Fri, 3 Oct 2008 10:09:02 -0400
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <290391.71932.qm@web35406.mail.mud.yahoo.com>
References: <c9ffea950810021111s3e3096f1y897ccdc439e7b512@mail.gmail.com>
	<290391.71932.qm@web35406.mail.mud.yahoo.com>
Message-ID: <c9ffea950810030709v722c5d91v5939ebc6848afe13@mail.gmail.com>

You need one other piece of gear then.   A dIstribution amplifier if
you do not already have one - they come up pretty frequently on ebay
and there is a thread on building the NIST reference design ongoing
the thread title is "homebrew 13 dBm distribution amplifier based on
NIST design 5 to 100 MHz"

On the DA you will want to ensure all your output cables are of
identical length as this will ensure that all signals are in phase at
the timebase input(s).   It's a small thing really a fraction of a
picosecond but it's there and easily compensated for.


On Thu, Oct 2, 2008 at 3:04 PM, Jeffrey Okamitsu <w3kl at w3kl.com> wrote:
> Scott.  Thanks for the information.  Tsuchiya-san provided the part number for the connector and I have already ordered one from Powell.
>
> I am looking forward to getting the unit up and running and providing a stable 10 MHz from which I will lock all of my frequency sensitive test equipment. (spectrum analyzer, network analyzer, synthesized signal generator, and frequency counter).
>
>
> Jeffrey K. Okamitsu, PhD, MBA
> +1-609-638-5402
>
> --- On Thu, 10/2/08, Scott McGrath <scmcgrath at gmail.com> wrote:
>
> From: Scott McGrath <scmcgrath at gmail.com>
> Subject: Re: [time-nuts] AC Connector On HP 5061B
> To: "Discussion of precise time and frequency measurement" <time-nuts at febo.com>
> Date: Thursday, October 2, 2008, 2:11 PM
>
> No I bought a 5061A a few weeks before unfortunately it has issues
> some of which are traceable to improper packing.   I'm surprised you
> did not buy the power cord (i did) on ebay.   The Cannon connectors
> are expensive but they can be had from Powell Electronics here in
> Massachusetts.
>
> I think someone here knows the part #
>
> The reason Parts are Unobtainium is Agilent sold the Time and
> Frequency divsion to Symmetricom and while some parts stock is still
> available from Agilent most of the people have moved on plus the 5061
> is a 20+ year old design and it was superceded by the microprocessor
> controlled 5071A which is an even better Cs device which is a couple
> of orders of magnitude better than our 5061x's.    On the other hand
> the 5061 is approachable by someone with a well equipped lab.
>
> But still we own devices which at one time were the exclusive domain
> of Govenments, national laboratories and aerospace firms.
>
> Welcome to the club!
>
> On Thu, Oct 2, 2008 at 11:09 AM, Jeffrey Okamitsu <w3kl at w3kl.com> wrote:
>> Scott, Tom.  Thanks for your input.  I am sure the unit was working before
> hand.  I will probably pop the top cover off and have a look.
>>
>> The schematic helps.  Thanks.
>>
>> Yes, this was the one on e-bay.  Was I bidding against you?
>>
>> Jeff
>>
>> Jeffrey K. Okamitsu, PhD, MBA
>> +1-609-638-5402
>>
>> --- On Thu, 10/2/08, Scott McGrath <scmcgrath at gmail.com> wrote:
>>
>> From: Scott McGrath <scmcgrath at gmail.com>
>> Subject: Re: [time-nuts] AC Connector On HP 5061B
>> To: "Tom Van Baak" <tvb at leapsecond.com>, "Discussion
> of precise time and frequency measurement" <time-nuts at febo.com>
>> Date: Thursday, October 2, 2008, 10:29 AM
>>
>> Was this the pretty one on Ebay?  - you really, really need to open it
>> up at least to ensure nothing came adrift in shipping, I'll second Tom
>> on the sheer coolness of the 5061B but also remember most of the
>> components in a Cesium beam fall under the category of
> "Unobtainium"
>> so you will want to ensure everything is as it should be.
>>
>> You will want to follow the preoperation checklist which can be found here
>>
>>
> http://www.home.agilent.com/agilent/facet.jspx?cc=US&lc=eng&t=80091.k.3&no=150
>>
>> On Thu, Oct 2, 2008 at 9:56 AM, Tom Van Baak <tvb at leapsecond.com>
> wrote:
>>>> I recently acquired an HP 5061B (Options 3 and 4). The system
>>>> came without an AC cable.
>>>>
>>>> I can easily make a replacement cable for the system. However,
>>>> I need to know the pin assignments. I can open the unit to look,
>>>> but if someone has the answer it would save me the hassle.
>>>
>>> You just got a 5061B and you don't want to open it? It is so cool
>>> looking inside, how can you resist?
>>>
>>> See the pin assignments in the 5061 manual:
>>> http://www.leapsecond.com/museum/hp5061a/5061a.pdf
>>>
>>> But, NEVER, make a power cord for something as precious as a
>>> 5061 without actually checking pins from the inside. On some
>>> models 5065/5061 that I have HP switched the pin assignments.
>>> See, for example,
>>>
>>> http://www.leapsecond.com/museum/hp5065a/conn.htm
>>>
>>>> Each of the pins on the jack at are assigned a letter.
> "G",
>> "A", and "B" (I think).
>>>> "G" is ground as it is connected to chassis (confirmed
> with
>> am ohmmeter).
>>>> Does anyone know which of the other two pins is AC hot and which
> is AC
>> neutral?
>>>
>>> The other way to check it is pull the fuse and measure which pin
>>> is connected to the ends of the fuse holder.
>>>
>>> /tvb
>>>
>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>


From sar10538 at gmail.com  Fri Oct  3 11:52:06 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Sat, 4 Oct 2008 04:52:06 +1300
Subject: [time-nuts] And, for my next trick, 50Hz
In-Reply-To: <48E5E671.9736.29558B@chris.cheney.tesco.net>
References: <1231b6a80810021741i64d779bj13948680658be749@mail.gmail.com>
	<48E5E671.9736.29558B@chris.cheney.tesco.net>
Message-ID: <1231b6a80810030852jd1d5fdexb9658afbee8c3390@mail.gmail.com>

Hi Chris,

2008/10/3 Chris Cheney <chris.cheney at tesco.net>:

> A bit of Googling finds:
>
> Frequency: "a variation not exceeding 1 per cent above or below the
> declared frequency;"
> (http://www.statutelaw.gov.uk/content.aspx?LegType=All+Legislation&title=e
> lectricity+safety+quality+continuity&searchEnacted=0&extentMatchOnly=0&con
> fersPower=0&blanketAmendment=0&sortAlpha=0&TYPE=QS&PageNumber=1&NavFrom=0&
> parentActiveTextDocId=1590332&ActiveTextDocId=1590368&filesize=4590 -
> section 27(3)(a))

Hmmm... that would make a mockery of keeping time on the large number
of  mains timed clocks in the UK. They would be out by a minute about
every hour and a half or a quarter of an hour each day, which would be
hopeless!

> Electric clock time: "NGET will endeavour (in so far as it is able) to
> control electric clock time to within plus or minus 10 seconds"
> (http://www.nationalgrid.com/NR/rdonlyres/4894C7AA-DCD2-4835-9986-
> 57338C31C86A/9922/BC3_i3r18.pdf - section BC3.4.3)

For some reason I could not get this link down, it just keeps stopping
about a third of the way through. The title does not give an idea of
the nature of the period for which the 10 seconds drift is acceptable.

> BTW wrt earthing via the incoming water main - in the UK, plastic pipe is
> commonly used for incoming water mains these days.

That is probably the case now so I guess they must put a local earth
spike instead. What I was trying to convey was that there was a local
earth at each house.

73
Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From w3kl at w3kl.com  Fri Oct  3 12:35:03 2008
From: w3kl at w3kl.com (Jeffrey Okamitsu)
Date: Fri, 3 Oct 2008 09:35:03 -0700 (PDT)
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <c9ffea950810030709v722c5d91v5939ebc6848afe13@mail.gmail.com>
Message-ID: <779066.76212.qm@web35401.mail.mud.yahoo.com>

Scott.? Yes, I'm working on acquiring a DA.? I'm also considering homebrewing one.? I've been watching the thread on the NIST design.
?
Jeff

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

--- On Fri, 10/3/08, Scott McGrath <scmcgrath at gmail.com> wrote:

From: Scott McGrath <scmcgrath at gmail.com>
Subject: Re: [time-nuts] AC Connector On HP 5061B
To: "Discussion of precise time and frequency measurement" <time-nuts at febo.com>
Date: Friday, October 3, 2008, 10:09 AM

You need one other piece of gear then.   A dIstribution amplifier if
you do not already have one - they come up pretty frequently on ebay
and there is a thread on building the NIST reference design ongoing
the thread title is "homebrew 13 dBm distribution amplifier based on
NIST design 5 to 100 MHz"

On the DA you will want to ensure all your output cables are of
identical length as this will ensure that all signals are in phase at
the timebase input(s).   It's a small thing really a fraction of a
picosecond but it's there and easily compensated for.


On Thu, Oct 2, 2008 at 3:04 PM, Jeffrey Okamitsu <w3kl at w3kl.com> wrote:
> Scott.  Thanks for the information.  Tsuchiya-san provided the part number
for the connector and I have already ordered one from Powell.
>
> I am looking forward to getting the unit up and running and providing a
stable 10 MHz from which I will lock all of my frequency sensitive test
equipment. (spectrum analyzer, network analyzer, synthesized signal generator,
and frequency counter).
>
>
> Jeffrey K. Okamitsu, PhD, MBA
> +1-609-638-5402
>
> --- On Thu, 10/2/08, Scott McGrath <scmcgrath at gmail.com> wrote:
>
> From: Scott McGrath <scmcgrath at gmail.com>
> Subject: Re: [time-nuts] AC Connector On HP 5061B
> To: "Discussion of precise time and frequency measurement"
<time-nuts at febo.com>
> Date: Thursday, October 2, 2008, 2:11 PM
>
> No I bought a 5061A a few weeks before unfortunately it has issues
> some of which are traceable to improper packing.   I'm surprised you
> did not buy the power cord (i did) on ebay.   The Cannon connectors
> are expensive but they can be had from Powell Electronics here in
> Massachusetts.
>
> I think someone here knows the part #
>
> The reason Parts are Unobtainium is Agilent sold the Time and
> Frequency divsion to Symmetricom and while some parts stock is still
> available from Agilent most of the people have moved on plus the 5061
> is a 20+ year old design and it was superceded by the microprocessor
> controlled 5071A which is an even better Cs device which is a couple
> of orders of magnitude better than our 5061x's.    On the other hand
> the 5061 is approachable by someone with a well equipped lab.
>
> But still we own devices which at one time were the exclusive domain
> of Govenments, national laboratories and aerospace firms.
>
> Welcome to the club!
>
> On Thu, Oct 2, 2008 at 11:09 AM, Jeffrey Okamitsu <w3kl at w3kl.com>
wrote:
>> Scott, Tom.  Thanks for your input.  I am sure the unit was working
before
> hand.  I will probably pop the top cover off and have a look.
>>
>> The schematic helps.  Thanks.
>>
>> Yes, this was the one on e-bay.  Was I bidding against you?
>>
>> Jeff
>>
>> Jeffrey K. Okamitsu, PhD, MBA
>> +1-609-638-5402
>>
>> --- On Thu, 10/2/08, Scott McGrath <scmcgrath at gmail.com> wrote:
>>
>> From: Scott McGrath <scmcgrath at gmail.com>
>> Subject: Re: [time-nuts] AC Connector On HP 5061B
>> To: "Tom Van Baak" <tvb at leapsecond.com>,
"Discussion
> of precise time and frequency measurement" <time-nuts at febo.com>
>> Date: Thursday, October 2, 2008, 10:29 AM
>>
>> Was this the pretty one on Ebay?  - you really, really need to open it
>> up at least to ensure nothing came adrift in shipping, I'll second
Tom
>> on the sheer coolness of the 5061B but also remember most of the
>> components in a Cesium beam fall under the category of
> "Unobtainium"
>> so you will want to ensure everything is as it should be.
>>
>> You will want to follow the preoperation checklist which can be found
here
>>
>>
>
http://www.home.agilent.com/agilent/facet.jspx?cc=US&lc=eng&t=80091.k.3&no=150
>>
>> On Thu, Oct 2, 2008 at 9:56 AM, Tom Van Baak
<tvb at leapsecond.com>
> wrote:
>>>> I recently acquired an HP 5061B (Options 3 and 4). The system
>>>> came without an AC cable.
>>>>
>>>> I can easily make a replacement cable for the system. However,
>>>> I need to know the pin assignments. I can open the unit to
look,
>>>> but if someone has the answer it would save me the hassle.
>>>
>>> You just got a 5061B and you don't want to open it? It is so
cool
>>> looking inside, how can you resist?
>>>
>>> See the pin assignments in the 5061 manual:
>>> http://www.leapsecond.com/museum/hp5061a/5061a.pdf
>>>
>>> But, NEVER, make a power cord for something as precious as a
>>> 5061 without actually checking pins from the inside. On some
>>> models 5065/5061 that I have HP switched the pin assignments.
>>> See, for example,
>>>
>>> http://www.leapsecond.com/museum/hp5065a/conn.htm
>>>
>>>> Each of the pins on the jack at are assigned a letter.
> "G",
>> "A", and "B" (I think).
>>>> "G" is ground as it is connected to chassis
(confirmed
> with
>> am ohmmeter).
>>>> Does anyone know which of the other two pins is AC hot and
which
> is AC
>> neutral?
>>>
>>> The other way to check it is pull the fuse and measure which pin
>>> is connected to the ends of the fuse holder.
>>>
>>> /tvb
>>>
>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

From sar10538 at gmail.com  Fri Oct  3 12:52:03 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Sat, 4 Oct 2008 05:52:03 +1300
Subject: [time-nuts] And, for my next trick, 50Hz
In-Reply-To: <002401c9250f$76694f40$0300a8c0@pc52>
References: <1231b6a80810021741i64d779bj13948680658be749@mail.gmail.com>
	<001301c924f2$511ed330$0300a8c0@pc52>
	<1231b6a80810022029t676bdcb7k1479ef0ad195ee1d@mail.gmail.com>
	<002401c9250f$76694f40$0300a8c0@pc52>
Message-ID: <1231b6a80810030952o2f33a8a6ubf9d5bdb108668a7@mail.gmail.com>

Tom,

2008/10/3 Tom Van Baak <tvb at leapsecond.com>:
> Ah, if you are a time-nut of course you will bite the bullet and
> get a GPSDO. But you should also not give up on the PC idea.
> If it works it will be a great gift to many people (OK, maybe not
> the pico- and nanosecond crowd, but to regular millisecond
> kind of folks).

Well, that's the way I plan to go now but as you say there is indeed
some merit in continuing with the idea of using NTP to check the
frequency of an oscillator as per my original idea. Certainly I
believe that figures in the milisecond area are probably achievable
without too much trouble.

> And, I no longer think long sample times are required.
>
> Consider the following. Assume you can get NTP to give you
> ms or sub-millisecond accurate time-stamps. Also assume you
> divide down your UUT to something like 1 kHz and feed that
> into one channel of your sound card (and as Bruce pointed
> out, maybe the slower the rise time the better in this case).
>
> Now, collect 16-bits of waveform data at 44.1 kHz. First, note
> that it's not exactly 44.100000 kHz -- but over time, as your
> circular input buffers fill up, you can use NTP time-stamps to
> calculate what the sampling rate precisely was/is.

This would produce a lot of data and be quite intensive in processor
time. Sampling the input waveform is easy as it's done in hardware on
the sound card but if we are time-stamping each sample with an
accurate wall time value that is going to be a lot of system calls and
I wonder if this may come out of sync at times.

> Then, looking at your highly oversampled waveform data, you
> can calculate the phase of your UUT frequency relative to the
> now precisely known sound card sampling rate. Over time you
> will see the phase drift, which then directly gives you the UUT
> frequency error.

It's a very interesting idea and I may have a go at this one.

> So what you end up doing is using the sound card like a high
> resolution vernier between NTP timekeeping on the inside and
> your UUT on the outside. I bet you a Thunderbolt that you can
> measure to 1 ppm within ten seconds.

Lets see, phase shift of 1ppm in 10 seconds at a sampling rate of
44KHz. So our error is 10^-6 so over 10 seconds becomes a 10^-5
change. Now 44KHz is a rate of 4.4x10^4 or 0.44x10^5. So that looks
like we would come up a bit short on data to verify the 1ppm
difference, IE. only 0.44 sample to indicate the error which would not
show up. at 10ppm we would have 4.4 samples to show the difference
which would be more workable. Is my logic wrong here or when do I get
my Thunderbolt?

> p.s. For extra credit, tee your UUT into both channels, do twice
> the math, and see if you can measure both differential phase,
> and differential phase drift between them.

This would really just check the phase difference between samples for
the two channels of the sound card and I would expect that to remain
fairly constant. It's an interesting point though, I wonder if both
channels are sampled simultaneously or in a serial fashion. If that
was the case, and assuming that the samples were equally spaced
between the two channels, you may get the equivalent of an 88KHz
sampling rate which would just push the ability of this system to
measure a 1ppm difference. I guess it depends on if the sound card
uses two A2D converter or just one and switches this between channels.
I think that switching it between channels may be a bit of a messy
affair due to the settling time needed before the sample is taken on
each channel.

So do I get two Thunderbolts now.

73, Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From sar10538 at gmail.com  Fri Oct  3 13:18:46 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Sat, 4 Oct 2008 06:18:46 +1300
Subject: [time-nuts] And, for my next trick, 50Hz
In-Reply-To: <1231b6a80810030952o2f33a8a6ubf9d5bdb108668a7@mail.gmail.com>
References: <1231b6a80810021741i64d779bj13948680658be749@mail.gmail.com>
	<001301c924f2$511ed330$0300a8c0@pc52>
	<1231b6a80810022029t676bdcb7k1479ef0ad195ee1d@mail.gmail.com>
	<002401c9250f$76694f40$0300a8c0@pc52>
	<1231b6a80810030952o2f33a8a6ubf9d5bdb108668a7@mail.gmail.com>
Message-ID: <1231b6a80810031018i2f8b005ah1045fa7547db1524@mail.gmail.com>

Tom,

Sorry to post in response to my previous post but perhaps this system
could work if the input signal did have a quite a slow rise time. I
was thinking more of coupling the output of the proposed 1KHz divider
through quite a small amount of low-pass filtration. If the 1KHz was
passed through a low-pass filter at the fundamental we would get a
sine-wave with a relatively slow rise time and the ability to get more
samples around the zero crossing point. Taking it a stage further, we
could pass our square wave though an integrator to produce a linear
sawtooth which would provide the best way to measure any phase shift.
Now I think this could work to gauge 1ppm in 10 seconds but you would
really need a short-term stable NTP disciplined clock to do it. I
wonder what the average allan variance would be for this setup over a
10 second period.

73, Steve

2008/10/4 Steve Rooke <sar10538 at gmail.com>:
> Tom,
>
> 2008/10/3 Tom Van Baak <tvb at leapsecond.com>:
>> Ah, if you are a time-nut of course you will bite the bullet and
>> get a GPSDO. But you should also not give up on the PC idea.
>> If it works it will be a great gift to many people (OK, maybe not
>> the pico- and nanosecond crowd, but to regular millisecond
>> kind of folks).
>
> Well, that's the way I plan to go now but as you say there is indeed
> some merit in continuing with the idea of using NTP to check the
> frequency of an oscillator as per my original idea. Certainly I
> believe that figures in the milisecond area are probably achievable
> without too much trouble.
>
>> And, I no longer think long sample times are required.
>>
>> Consider the following. Assume you can get NTP to give you
>> ms or sub-millisecond accurate time-stamps. Also assume you
>> divide down your UUT to something like 1 kHz and feed that
>> into one channel of your sound card (and as Bruce pointed
>> out, maybe the slower the rise time the better in this case).
>>
>> Now, collect 16-bits of waveform data at 44.1 kHz. First, note
>> that it's not exactly 44.100000 kHz -- but over time, as your
>> circular input buffers fill up, you can use NTP time-stamps to
>> calculate what the sampling rate precisely was/is.
>
> This would produce a lot of data and be quite intensive in processor
> time. Sampling the input waveform is easy as it's done in hardware on
> the sound card but if we are time-stamping each sample with an
> accurate wall time value that is going to be a lot of system calls and
> I wonder if this may come out of sync at times.
>
>> Then, looking at your highly oversampled waveform data, you
>> can calculate the phase of your UUT frequency relative to the
>> now precisely known sound card sampling rate. Over time you
>> will see the phase drift, which then directly gives you the UUT
>> frequency error.
>
> It's a very interesting idea and I may have a go at this one.
>
>> So what you end up doing is using the sound card like a high
>> resolution vernier between NTP timekeeping on the inside and
>> your UUT on the outside. I bet you a Thunderbolt that you can
>> measure to 1 ppm within ten seconds.
>
> Lets see, phase shift of 1ppm in 10 seconds at a sampling rate of
> 44KHz. So our error is 10^-6 so over 10 seconds becomes a 10^-5
> change. Now 44KHz is a rate of 4.4x10^4 or 0.44x10^5. So that looks
> like we would come up a bit short on data to verify the 1ppm
> difference, IE. only 0.44 sample to indicate the error which would not
> show up. at 10ppm we would have 4.4 samples to show the difference
> which would be more workable. Is my logic wrong here or when do I get
> my Thunderbolt?
>
>> p.s. For extra credit, tee your UUT into both channels, do twice
>> the math, and see if you can measure both differential phase,
>> and differential phase drift between them.
>
> This would really just check the phase difference between samples for
> the two channels of the sound card and I would expect that to remain
> fairly constant. It's an interesting point though, I wonder if both
> channels are sampled simultaneously or in a serial fashion. If that
> was the case, and assuming that the samples were equally spaced
> between the two channels, you may get the equivalent of an 88KHz
> sampling rate which would just push the ability of this system to
> measure a 1ppm difference. I guess it depends on if the sound card
> uses two A2D converter or just one and switches this between channels.
> I think that switching it between channels may be a bit of a messy
> affair due to the settling time needed before the sample is taken on
> each channel.
>
> So do I get two Thunderbolts now.
>
> 73, Steve
> --
> Steve Rooke - ZL3TUV & G8KVD
> Omnium finis imminet
>



-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From hmurray at megapathdsl.net  Fri Oct  3 13:51:47 2008
From: hmurray at megapathdsl.net (Hal Murray)
Date: Fri, 03 Oct 2008 10:51:47 -0700
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: Message from "Scott McGrath" <scmcgrath@gmail.com> of "Fri,
	03 Oct 2008 10:09:02 EDT."
	<c9ffea950810030709v722c5d91v5939ebc6848afe13@mail.gmail.com> 
Message-ID: <20081003175148.E1A5ABCD5@ip-64-139-1-69.sjc.megapath.net>


> On the DA you will want to ensure all your output cables are of
> identical length as this will ensure that all signals are in phase at
> the timebase input(s).   It's a small thing really a fraction of a
> picosecond but it's there and easily compensated for. 

If you are after picoseconds, you have to match cable lengths very carefully.

The rule of thumb is a foot per nanosecond.  Coax is slower: roughly 1/2 for 
junk but faster for good (low loss) coax.

The way I remember the number for fibers (and good coax) is that 1 ft/ns 
would be 5 microseconds per mile.  Fiber is 5 microseconds per kilometer.

All you need to calculate the speed of light is the dielectric constant.  
(I'd have to dig out a book to find the formula.  It's probably k/squt(e))  
Good coax is mostly air which reduces the dielectric constant and speeds up 
light.  Similarly, traces on the outside layers of a PCB (half air if you 
neglect the solder mask) are faster than traces on inside layers.

Good coax uses foam rather than solid dielectric.  It's mostly air which 
reduces the dielectric constant.




-- 
These are my opinions, not necessarily my employer's.  I hate spam.





From w3kl at w3kl.com  Fri Oct  3 14:01:43 2008
From: w3kl at w3kl.com (Jeffrey Okamitsu)
Date: Fri, 3 Oct 2008 11:01:43 -0700 (PDT)
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <20081003175148.E1A5ABCD5@ip-64-139-1-69.sjc.megapath.net>
Message-ID: <308300.65077.qm@web35402.mail.mud.yahoo.com>

A better way to cut coax to the right delay lengths is to use a network analyzer.
?

From tvb at LeapSecond.com  Fri Oct  3 14:19:36 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Fri, 3 Oct 2008 11:19:36 -0700
Subject: [time-nuts] AC Connector On HP 5061B
References: <c9ffea950810021111s3e3096f1y897ccdc439e7b512@mail.gmail.com><290391.71932.qm@web35406.mail.mud.yahoo.com>
	<c9ffea950810030709v722c5d91v5939ebc6848afe13@mail.gmail.com>
Message-ID: <002f01c92584$97dc0760$0300a8c0@pc52>

> On the DA you will want to ensure all your output cables are of
> identical length as this will ensure that all signals are in phase at
> the timebase input(s).   It's a small thing really a fraction of a
> picosecond but it's there and easily compensated for.

When does the phase of the timebase input mean anything?
Most test equipment is happy to have a stable external frequency
input; the phase is immaterial, no? Can someone give me an
example when relative phase among various random pieces of
test equipment is important?

/tvb



From david.partridge at dsl.pipex.com  Fri Oct  3 14:32:12 2008
From: david.partridge at dsl.pipex.com (David C. Partridge)
Date: Fri, 3 Oct 2008 19:32:12 +0100
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <308300.65077.qm@web35402.mail.mud.yahoo.com>
References: <20081003175148.E1A5ABCD5@ip-64-139-1-69.sjc.megapath.net>
	<308300.65077.qm@web35402.mail.mud.yahoo.com>
Message-ID: <7FBAF7A76AD042279F5F8A7AB6934669@APOLLO>

Or use a TDR like the Tektronix 7S12.

RG400 (solid PTFE dielectrice IIRC) in my experience typically comes out at
about 8.6" per nS which is slightly at odds with the published propogation
speed of .69 which would suggest 8.28".   The 5nS cables I made up not long
back are almost exactly 43" long.

RG58 has a published propogation velocity of .66 (8" per nS) but tends to
vary rather more in characteristics (electrical length versus measured
length).

Dave 

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Jeffrey Okamitsu
Sent: 03 October 2008 19:02
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] AC Connector On HP 5061B

A better way to cut coax to the right delay lengths is to use a network
analyzer.
?



From tvb at LeapSecond.com  Fri Oct  3 14:33:11 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Fri, 3 Oct 2008 11:33:11 -0700
Subject: [time-nuts] And, for my next trick, 50Hz
References: <1231b6a80810021741i64d779bj13948680658be749@mail.gmail.com>
	<001301c924f2$511ed330$0300a8c0@pc52>
	<1231b6a80810022029t676bdcb7k1479ef0ad195ee1d@mail.gmail.com>
	<002401c9250f$76694f40$0300a8c0@pc52>
	<1231b6a80810030952o2f33a8a6ubf9d5bdb108668a7@mail.gmail.com>
Message-ID: <003401c92586$7dacc5d0$0300a8c0@pc52>

> This would produce a lot of data and be quite intensive in processor
> time. Sampling the input waveform is easy as it's done in hardware on

There's no need to time-stamp each sample (and I'm not sure
this is even possible with sound card API's). What I meant is to
time-stamp each sound card input buffer completion interrupt.

For example, a 512 byte buffer would give you 86.1 interrupts
per second which should be plenty of time-stamps to precisely
determine the relative clock rates of NTP vs. the sound card
without creating much overhead.

You could play with the trade-off of buffer size and the number
of circular buffers to achieve both the desired precision and the
desired reliability. Your precision goal is to know the frequency
offset of the sound card to 1ppm vs. NTP. Your reliability goal is
zero input buffer data loss.

> Lets see, phase shift of 1ppm in 10 seconds at a sampling rate of
> 44KHz. So our error is 10^-6 so over 10 seconds becomes a 10^-5
> change. Now 44KHz is a rate of 4.4x10^4 or 0.44x10^5. So that looks
> like we would come up a bit short on data to verify the 1ppm
> difference, IE. only 0.44 sample to indicate the error which would not
> show up. at 10ppm we would have 4.4 samples to show the difference
> which would be more workable. Is my logic wrong here or when do I get
> my Thunderbolt?

My calculations were -- a frequency error of 1 ppm is a 1 us per
second phase drift. Since you are sampling at 44.1 kHz (which
is one sample every 22.67 us) the leading edge (or the peak, or
centroid, or whatever) of the sampled UUT waveform will drift by
one "quantum" (a sample bucket) in just 22 seconds. I think we
are on the same page so far.

Now, with not much math, and because you see 1000 waveforms
per second, you should be able to nail down the *average* phase
of the UUT to less than one bucket; depending on the noise level,
maybe way less than one bucket. But if even half a bucket, you'd
detect 1ppm in 10 seconds. At least that was my hunch.

Note that since the UUT frequency (nominally 1 kHz) is not exactly
synchronized with the sound card sampling frequency (nominally
44.1 kHz) the saw-tooth like effect you will see is also to your
great advantage.

In addition, any modest jitter in the sound card or in your UUT will
further make your phase measurements average down better than
one bucket.

Watching the std dev of your edge detect measurements would
be a good indication of how long you actually need to continue
sampling in order to meet a 1 ppm resolution goal. Clearly, if
you can't nail down the UUT waveform to even within ten 44.1 kHz
samples, you're talking a frequency measurement duration of
minutes rather than seconds.

/tvb
http://www.LeapSecond.com




From chris.cheney at tesco.net  Fri Oct  3 15:10:20 2008
From: chris.cheney at tesco.net (Chris Cheney)
Date: Fri, 03 Oct 2008 20:10:20 +0100
Subject: [time-nuts] And, for my next trick, 50Hz
In-Reply-To: <1231b6a80810030852jd1d5fdexb9658afbee8c3390@mail.gmail.com>
References: <1231b6a80810021741i64d779bj13948680658be749@mail.gmail.com>,
	<48E5E671.9736.29558B@chris.cheney.tesco.net>,
	<1231b6a80810030852jd1d5fdexb9658afbee8c3390@mail.gmail.com>
Message-ID: <48E67C2C.17795.2723E4C@chris.cheney.tesco.net>

> > Electric clock time: "NGET will endeavour (in so far as it is able) to
> > control electric clock time to within plus or minus 10 seconds"
> > (http://www.nationalgrid.com/NR/rdonlyres/4894C7AA-DCD2-4835-9986-
> > 57338C31C86A/9922/BC3_i3r18.pdf - section BC3.4.3)
> 
> For some reason I could not get this link down, it just keeps stopping
> about a third of the way through. The title does not give an idea of the
> nature of the period for which the 10 seconds drift is acceptable.

I don't have a problem with the page (using either Firefox or IE). FWIW 
here is the whole of the relevant paragraph

BC3.4.3 Electric Time
NGET will endeavour (in so far as it is able) to control electric clock 
time to within
plus or minus 10 seconds by specifying changes to Target Frequency, by
accepting bids and offers in the Balancing Mechanism. Errors greater than 
plus
or minus 10 seconds may be temporarily accepted at NGET's reasonable
discretion.

I believe that they are saying that the accumulated phase error will 
normally be less than 10 seconds worth, but that amount of phase error 
may exist indefinitely.

73
Chris
G3RSE


From holrum at hotmail.com  Fri Oct  3 15:12:55 2008
From: holrum at hotmail.com (Mark Sims)
Date: Fri, 3 Oct 2008 19:12:55 +0000
Subject: [time-nuts] HP 5371A problem
In-Reply-To: <mailman.238.1223057986.2205.time-nuts@febo.com>
References: <mailman.238.1223057986.2205.time-nuts@febo.com>
Message-ID: <BLU125-W34A993D0BA7B9A5C36A969CE3C0@phx.gbl>


I have an HP5371A with a problem.  It fails the Input Amplifier test.
The error message says Bad Comparator: Result A: stuck low.

If you do a auto trigger level set,  channel A gives flakey readings.
When measuring the internal timebase signal (patching the back 
panel BNC to the input pods) "auto trigger" on channel A
sets the threshold around -1.2V,  channel B gives around -26 mV.

If you manually set the channel A trigger level it seems to work fine.
Changing the "A" threshold a few percent will give good readings.  This
makes me suspect that  the comparator hybrid may not be at fault.

Any ideas of what is going on or how to fix it? I did swap the card 
with another machine and the problem is with the A2 card.

Or does anybody have a spare A2 input amp card for a 5371A?  
----------------------------------------

_________________________________________________________________
Get more out of the Web. Learn 10 hidden secrets of Windows Live.
http://windowslive.com/connect/post/jamiethomson.spaces.live.com-Blog-cns!550F681DAD532637!5295.entry?ocid=TXT_TAGLM_WL_domore_092008

From wb6bnq at cox.net  Fri Oct  3 15:21:30 2008
From: wb6bnq at cox.net (WB6BNQ)
Date: Fri, 03 Oct 2008 12:21:30 -0700
Subject: [time-nuts] AC Connector On HP 5061B
References: <c9ffea950810021111s3e3096f1y897ccdc439e7b512@mail.gmail.com><290391.71932.qm@web35406.mail.mud.yahoo.com>
	<c9ffea950810030709v722c5d91v5939ebc6848afe13@mail.gmail.com>
	<002f01c92584$97dc0760$0300a8c0@pc52>
Message-ID: <48E670BA.DEDBB045@cox.net>

Tom Van Baak wrote:

> > On the DA you will want to ensure all your output cables are of
> > identical length as this will ensure that all signals are in phase at
> > the timebase input(s).   It's a small thing really a fraction of a
> > picosecond but it's there and easily compensated for.
>
> When does the phase of the timebase input mean anything?
> Most test equipment is happy to have a stable external frequency
> input; the phase is immaterial, no? Can someone give me an
> example when relative phase among various random pieces of
> test equipment is important?
>
> /tvb

Hi Tom,

Your absolutely right.  The only two places that I can think of, off hand, would
be televison and RADAR (systems with multiple terminals).

Bill....WB6BNQ




From dforbes at dakotacom.net  Fri Oct  3 15:26:40 2008
From: dforbes at dakotacom.net (David Forbes)
Date: Fri, 03 Oct 2008 12:26:40 -0700
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <48E670BA.DEDBB045@cox.net>
References: <c9ffea950810021111s3e3096f1y897ccdc439e7b512@mail.gmail.com><290391.71932.qm@web35406.mail.mud.yahoo.com>	<c9ffea950810030709v722c5d91v5939ebc6848afe13@mail.gmail.com>	<002f01c92584$97dc0760$0300a8c0@pc52>
	<48E670BA.DEDBB045@cox.net>
Message-ID: <48E671F0.8050407@dakotacom.net>

WB6BNQ wrote:
> Tom Van Baak wrote:
> 
>>> On the DA you will want to ensure all your output cables are of
>>> identical length as this will ensure that all signals are in phase at
>>> the timebase input(s).   It's a small thing really a fraction of a
>>> picosecond but it's there and easily compensated for.
>> When does the phase of the timebase input mean anything?
>> Most test equipment is happy to have a stable external frequency
>> input; the phase is immaterial, no? Can someone give me an
>> example when relative phase among various random pieces of
>> test equipment is important?
>>
>> /tvb
> 
> Hi Tom,
> 
> Your absolutely right.  The only two places that I can think of, off hand, would
> be televison and RADAR (systems with multiple terminals).
> 
> Bill....WB6BNQ

A counterexample would be a sampling system, in which it is required that the 
sample clock be free-running relative to the signal clock. Otherwise all samples 
will be at the same few points in the input waveform!


From bruce.griffiths at xtra.co.nz  Fri Oct  3 15:58:26 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Sat, 04 Oct 2008 08:58:26 +1300
Subject: [time-nuts] And, for my next trick, 50Hz
In-Reply-To: <1231b6a80810030952o2f33a8a6ubf9d5bdb108668a7@mail.gmail.com>
References: <1231b6a80810021741i64d779bj13948680658be749@mail.gmail.com>	<001301c924f2$511ed330$0300a8c0@pc52>	<1231b6a80810022029t676bdcb7k1479ef0ad195ee1d@mail.gmail.com>	<002401c9250f$76694f40$0300a8c0@pc52>
	<1231b6a80810030952o2f33a8a6ubf9d5bdb108668a7@mail.gmail.com>
Message-ID: <48E67962.5000908@xtra.co.nz>

Steve
>> So what you end up doing is using the sound card like a high
>> resolution vernier between NTP timekeeping on the inside and
>> your UUT on the outside. I bet you a Thunderbolt that you can
>> measure to 1 ppm within ten seconds.
>>     
>
> Lets see, phase shift of 1ppm in 10 seconds at a sampling rate of
> 44KHz. So our error is 10^-6 so over 10 seconds becomes a 10^-5
> change. Now 44KHz is a rate of 4.4x10^4 or 0.44x10^5. So that looks
> like we would come up a bit short on data to verify the 1ppm
> difference, IE. only 0.44 sample to indicate the error which would not
> show up. at 10ppm we would have 4.4 samples to show the difference
> which would be more workable. Is my logic wrong here or when do I get
> my Thunderbolt?
>
>   
Try WKS interpolation (or even linear interpolation if you have enough 
samples of the signal transitions) to achieve sub sampling period 
resolution.
All the information required to do this is contained within the sample 
stream.
This is how jitter is measured with a digital oscilloscope with ps or 
even sub ps resolution even though no digital oscilloscope yet has a 
sample rate anywhere near 1 THz.
>> p.s. For extra credit, tee your UUT into both channels, do twice
>> the math, and see if you can measure both differential phase,
>> and differential phase drift between them.
>>     
>
> This would really just check the phase difference between samples for
> the two channels of the sound card and I would expect that to remain
> fairly constant. It's an interesting point though, I wonder if both
> channels are sampled simultaneously or in a serial fashion. If that
> was the case, and assuming that the samples were equally spaced
> between the two channels, you may get the equivalent of an 88KHz
> sampling rate which would just push the ability of this system to
> measure a 1ppm difference. I guess it depends on if the sound card
> uses two A2D converter or just one and switches this between channels.
> I think that switching it between channels may be a bit of a messy
> affair due to the settling time needed before the sample is taken on
> each channel.
>
>   
All sound cards of any use have separate ADCs (usually on the same 
chip), one ADC for the L channel and one for the R channel.
Since they tend to use sigma delta ADCs and don't use incremental form, 
switching an ADC dynamically between channels is impractical due to the 
long group delay of the associated digital filters.
The point of such a measurement is to measure the internal measurement 
noise of the sound card system.
> So do I get two Thunderbolts now.
>
> 73, Steve
>   

Bruce



From bruce.griffiths at xtra.co.nz  Fri Oct  3 16:01:14 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Sat, 04 Oct 2008 09:01:14 +1300
Subject: [time-nuts] And, for my next trick, 50Hz
In-Reply-To: <1231b6a80810031018i2f8b005ah1045fa7547db1524@mail.gmail.com>
References: <1231b6a80810021741i64d779bj13948680658be749@mail.gmail.com>	<001301c924f2$511ed330$0300a8c0@pc52>	<1231b6a80810022029t676bdcb7k1479ef0ad195ee1d@mail.gmail.com>	<002401c9250f$76694f40$0300a8c0@pc52>	<1231b6a80810030952o2f33a8a6ubf9d5bdb108668a7@mail.gmail.com>
	<1231b6a80810031018i2f8b005ah1045fa7547db1524@mail.gmail.com>
Message-ID: <48E67A0A.5090303@xtra.co.nz>

Steve Rooke wrote:
> Tom,
>
> Sorry to post in response to my previous post but perhaps this system
> could work if the input signal did have a quite a slow rise time. I
> was thinking more of coupling the output of the proposed 1KHz divider
> through quite a small amount of low-pass filtration. If the 1KHz was
> passed through a low-pass filter at the fundamental we would get a
> sine-wave with a relatively slow rise time and the ability to get more
> samples around the zero crossing point. Taking it a stage further, we
> could pass our square wave though an integrator to produce a linear
> sawtooth which would provide the best way to measure any phase shift.
> Now I think this could work to gauge 1ppm in 10 seconds but you would
> really need a short-term stable NTP disciplined clock to do it. I
> wonder what the average allan variance would be for this setup over a
> 10 second period.
>
> 73, Steve
>
>   
Steve

With interpolation you dont need to slow the signal transitions too much.
A transition suficient to allow 3 or 4 samples to be taken during the 
transition is adequate.
If the signal slew rate is too slow sound card input noise and the 
finite ADC resolution will increase the measuremnet noise.

Bruce


From scmcgrath at gmail.com  Fri Oct  3 16:21:25 2008
From: scmcgrath at gmail.com (Scott McGrath)
Date: Fri, 3 Oct 2008 16:21:25 -0400
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <002f01c92584$97dc0760$0300a8c0@pc52>
References: <c9ffea950810021111s3e3096f1y897ccdc439e7b512@mail.gmail.com>
	<290391.71932.qm@web35406.mail.mud.yahoo.com>
	<c9ffea950810030709v722c5d91v5939ebc6848afe13@mail.gmail.com>
	<002f01c92584$97dc0760$0300a8c0@pc52>
Message-ID: <c9ffea950810031321h5bee1811g62860b0255978e0a@mail.gmail.com>

Tom,

You are correct - I let my college years buidling coincidence
detectors in college for the GRO-COMPTEL   as well as  television
broadcast engineering.  in both applications  it mattered whether all
instruments used were in precisely defined phase relationships and I
have been letting this influence my thinking for too many years.

I had just never stopped to think about it before I've just been
happily building cables mesured with excruciating precision and
building cables for projects using the same spool of cable to ensure
consistent delays thinking this was important but in reality is is
not.



On Fri, Oct 3, 2008 at 2:19 PM, Tom Van Baak <tvb at leapsecond.com> wrote:
>> On the DA you will want to ensure all your output cables are of
>> identical length as this will ensure that all signals are in phase at
>> the timebase input(s).   It's a small thing really a fraction of a
>> picosecond but it's there and easily compensated for.
>
> When does the phase of the timebase input mean anything?
> Most test equipment is happy to have a stable external frequency
> input; the phase is immaterial, no? Can someone give me an
> example when relative phase among various random pieces of
> test equipment is important?
>
> /tvb
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>


From james.p.lux at jpl.nasa.gov  Fri Oct  3 16:50:24 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Fri, 3 Oct 2008 13:50:24 -0700
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <48E670BA.DEDBB045@cox.net>
References: <c9ffea950810021111s3e3096f1y897ccdc439e7b512@mail.gmail.com><290391.71932.qm@web35406.mail.mud.yahoo.com>
	<c9ffea950810030709v722c5d91v5939ebc6848afe13@mail.gmail.com>
	<002f01c92584$97dc0760$0300a8c0@pc52> <48E670BA.DEDBB045@cox.net>
Message-ID: <ECE7A93BD093E1439C20020FBE87C47FEB52281F3F@ALTPHYEMBEVSP20.RES.AD.JPL>


> > When does the phase of the timebase input mean anything?
> > Most test equipment is happy to have a stable external frequency
> > input; the phase is immaterial, no? Can someone give me an example
> > when relative phase among various random pieces of test
> equipment is
> > important?
> >
> > /tvb
>
> Hi Tom,
>
> Your absolutely right.  The only two places that I can think
> of, off hand, would be televison and RADAR (systems with
> multiple terminals).
>
> Bill....WB6BNQ
>
>

Interferometers are another.


From bruce.griffiths at xtra.co.nz  Fri Oct  3 16:50:26 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Sat, 04 Oct 2008 09:50:26 +1300
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <002f01c92584$97dc0760$0300a8c0@pc52>
References: <c9ffea950810021111s3e3096f1y897ccdc439e7b512@mail.gmail.com><290391.71932.qm@web35406.mail.mud.yahoo.com>	<c9ffea950810030709v722c5d91v5939ebc6848afe13@mail.gmail.com>
	<002f01c92584$97dc0760$0300a8c0@pc52>
Message-ID: <48E68592.7070509@xtra.co.nz>

Tom Van Baak wrote:
>> On the DA you will want to ensure all your output cables are of
>> identical length as this will ensure that all signals are in phase at
>> the timebase input(s).   It's a small thing really a fraction of a
>> picosecond but it's there and easily compensated for.
>>     
>
> When does the phase of the timebase input mean anything?
> Most test equipment is happy to have a stable external frequency
> input; the phase is immaterial, no? Can someone give me an
> example when relative phase among various random pieces of
> test equipment is important?
>
> /tvb
>
>   
Tom

The relative phase between 2 inputs to an interferometer (bridge) is 
important as is the relative phase between the LO and RF inputs of a 
mixer when measuring the internal noise by driving the LO and RF ports 
from the same source.

Bruce



From bruce.griffiths at xtra.co.nz  Fri Oct  3 16:58:58 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Sat, 04 Oct 2008 09:58:58 +1300
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <002f01c92584$97dc0760$0300a8c0@pc52>
References: <c9ffea950810021111s3e3096f1y897ccdc439e7b512@mail.gmail.com><290391.71932.qm@web35406.mail.mud.yahoo.com>	<c9ffea950810030709v722c5d91v5939ebc6848afe13@mail.gmail.com>
	<002f01c92584$97dc0760$0300a8c0@pc52>
Message-ID: <48E68792.3020300@xtra.co.nz>

Tom Van Baak wrote:
>> On the DA you will want to ensure all your output cables are of
>> identical length as this will ensure that all signals are in phase at
>> the timebase input(s).   It's a small thing really a fraction of a
>> picosecond but it's there and easily compensated for.
>>     
>
> When does the phase of the timebase input mean anything?
> Most test equipment is happy to have a stable external frequency
> input; the phase is immaterial, no? Can someone give me an
> example when relative phase among various random pieces of
> test equipment is important?
>
> /tvb
>
>   
Tom

Another example of a case where the electrical length of a cable can be 
important is in precision frequency distribution systems.
Trimming the cable to the right length (one way propagation delay equal 
to an odd multiple of half the signal period) for the frequency in use 
minimises the effect of load and source mismatch.

Bruce


From rvassar at rob-vassar.com  Fri Oct  3 17:39:31 2008
From: rvassar at rob-vassar.com (Robert Vassar)
Date: Fri, 3 Oct 2008 16:39:31 -0500
Subject: [time-nuts] GPS, NTP, and Cisco routers...
Message-ID: <3C932D37-8120-4833-81D8-9AC8C1E73434@rob-vassar.com>




I've been fiddling around with an old Cisco router here at the house  
to brush up.  We have an IPv6 project going at work, and our WAN  
provider provides no native transit, so I'm looking at doing some  
tunneling.  Anyhow... I discovered IOS 12.1 and above have native NTP  
capability.  I don't have the exhaustive IOS command reference, and I  
suspect it's a limited NTP implementation. I'm wondering if it's  
possible to tie a GPS unit to a router serial port and gain a stratum  
0 refclock.


Any Cisco guru's on the list?  :-)



Cheers,

Rob 
  


From w3kl at w3kl.com  Fri Oct  3 17:44:25 2008
From: w3kl at w3kl.com (Jeffrey Okamitsu)
Date: Fri, 3 Oct 2008 14:44:25 -0700 (PDT)
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <48E68792.3020300@xtra.co.nz>
Message-ID: <913340.18113.qm@web35408.mail.mud.yahoo.com>

In this case, cable quality is critical and controlling cable characteristics (as a function of temperature, humidity, etc.) is also critical.
?
Jeff

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

--- On Fri, 10/3/08, Bruce Griffiths <bruce.griffiths at xtra.co.nz> wrote:

From: Bruce Griffiths <bruce.griffiths at xtra.co.nz>
Subject: Re: [time-nuts] AC Connector On HP 5061B
To: "Tom Van Baak" <tvb at leapsecond.com>, "Discussion of precise time and frequency measurement" <time-nuts at febo.com>
Date: Friday, October 3, 2008, 4:58 PM

Tom Van Baak wrote:
>> On the DA you will want to ensure all your output cables are of
>> identical length as this will ensure that all signals are in phase at
>> the timebase input(s).   It's a small thing really a fraction of a
>> picosecond but it's there and easily compensated for.
>>     
>
> When does the phase of the timebase input mean anything?
> Most test equipment is happy to have a stable external frequency
> input; the phase is immaterial, no? Can someone give me an
> example when relative phase among various random pieces of
> test equipment is important?
>
> /tvb
>
>   
Tom

Another example of a case where the electrical length of a cable can be 
important is in precision frequency distribution systems.
Trimming the cable to the right length (one way propagation delay equal 
to an odd multiple of half the signal period) for the frequency in use 
minimises the effect of load and source mismatch.

Bruce

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

From w3kl at w3kl.com  Fri Oct  3 17:45:42 2008
From: w3kl at w3kl.com (Jeffrey Okamitsu)
Date: Fri, 3 Oct 2008 14:45:42 -0700 (PDT)
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <ECE7A93BD093E1439C20020FBE87C47FEB52281F3F@ALTPHYEMBEVSP20.RES.AD.JPL>
Message-ID: <284286.56741.qm@web35405.mail.mud.yahoo.com>

For an interferometric application, isn't it sufficient to maintain constant phase difference?
?
Jeff

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

--- On Fri, 10/3/08, Lux, James P <james.p.lux at jpl.nasa.gov> wrote:

From: Lux, James P <james.p.lux at jpl.nasa.gov>
Subject: Re: [time-nuts] AC Connector On HP 5061B
To: "Discussion of precise time and frequency measurement" <time-nuts at febo.com>, "Tom Van Baak" <tvb at leapsecond.com>
Date: Friday, October 3, 2008, 4:50 PM

> > When does the phase of the timebase input mean anything?
> > Most test equipment is happy to have a stable external frequency
> > input; the phase is immaterial, no? Can someone give me an example
> > when relative phase among various random pieces of test
> equipment is
> > important?
> >
> > /tvb
>
> Hi Tom,
>
> Your absolutely right.  The only two places that I can think
> of, off hand, would be televison and RADAR (systems with
> multiple terminals).
>
> Bill....WB6BNQ
>
>

Interferometers are another.

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

From james.p.lux at jpl.nasa.gov  Fri Oct  3 18:28:25 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Fri, 3 Oct 2008 15:28:25 -0700
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <284286.56741.qm@web35405.mail.mud.yahoo.com>
References: <ECE7A93BD093E1439C20020FBE87C47FEB52281F3F@ALTPHYEMBEVSP20.RES.AD.JPL>
	<284286.56741.qm@web35405.mail.mud.yahoo.com>
Message-ID: <ECE7A93BD093E1439C20020FBE87C47FEB52281F43@ALTPHYEMBEVSP20.RES.AD.JPL>



> -----Original Message-----
> From: time-nuts-bounces at febo.com
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Jeffrey Okamitsu
> Sent: Friday, October 03, 2008 2:46 PM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] AC Connector On HP 5061B
>
> For an interferometric application, isn't it sufficient to
> maintain constant phase difference?
>
> Jeff
>
> Jeffrey K. Okamitsu, PhD, MBA
> +1-609-638-5402
>
> >
> > Your absolutely right.  The only two places that I can
> think of, off
> > hand, would be televison and RADAR (systems with multiple
> terminals).
> >
> > Bill....WB6BNQ
> >
> >
>
> Interferometers are another.
>


Jeff is right, BUT, keeping constant phase difference without equal length cables can be challenging. Consider a system I worked on which used phase difference between 7 GHz signals received between two antennas about a meter apart to steer a return beam at 32GHz back the same direction. And, it has to do this while subject to temperature variations from -40 to +80C.



James Lux, P.E.
Task Manager, SOMD Software Defined Radios
Flight Communications Systems Section
Jet Propulsion Laboratory
4800 Oak Grove Drive, Mail Stop 161-213
Pasadena, CA, 91109
+1(818)354-2075 phone
+1(818)393-6875 fax



From d.seiter at comcast.net  Fri Oct  3 18:45:55 2008
From: d.seiter at comcast.net (d.seiter at comcast.net)
Date: Fri, 03 Oct 2008 22:45:55 +0000
Subject: [time-nuts] AC Connector On HP 5061B
Message-ID: <100320082245.10820.48E6A0A30002059700002A4422007456729D0A9B070A9CD20B@comcast.net>

The cable length issue was a pain for me because I built my GPS box in stages, leaving the dist amp for last.  In the end I found a nice used commercial unit, but it didn't fit in the planned location (the unit I was going to build would have had outputs near the center of the box), so I have 3 nicely routed cables going to the front panel, and the other 5 are ugly coils stuffed above and below the Z3801A for the rear panel.

-Dave


> 
> On the DA you will want to ensure all your output cables are of 
> identical length as this will ensure that all signals are in phase at 
> the timebase input(s). It's a small thing really a fraction of a 
> picosecond but it's there and easily compensated for. 
> 

From bruce.griffiths at xtra.co.nz  Fri Oct  3 18:57:23 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Sat, 04 Oct 2008 11:57:23 +1300
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <ECE7A93BD093E1439C20020FBE87C47FEB52281F43@ALTPHYEMBEVSP20.RES.AD.JPL>
References: <ECE7A93BD093E1439C20020FBE87C47FEB52281F3F@ALTPHYEMBEVSP20.RES.AD.JPL>	<284286.56741.qm@web35405.mail.mud.yahoo.com>
	<ECE7A93BD093E1439C20020FBE87C47FEB52281F43@ALTPHYEMBEVSP20.RES.AD.JPL>
Message-ID: <48E6A353.7000503@xtra.co.nz>

Lux, James P wrote:
>   
>> -----Original Message-----
>> From: time-nuts-bounces at febo.com
>> [mailto:time-nuts-bounces at febo.com] On Behalf Of Jeffrey Okamitsu
>> Sent: Friday, October 03, 2008 2:46 PM
>> To: Discussion of precise time and frequency measurement
>> Subject: Re: [time-nuts] AC Connector On HP 5061B
>>
>> For an interferometric application, isn't it sufficient to
>> maintain constant phase difference?
>>
>> Jeff
>>
>> Jeffrey K. Okamitsu, PhD, MBA
>> +1-609-638-5402
>>
>>     
>>> Your absolutely right.  The only two places that I can
>>>       
>> think of, off
>>     
>>> hand, would be televison and RADAR (systems with multiple
>>>       
>> terminals).
>>     
>>> Bill....WB6BNQ
>>>
>>>
>>>       
>> Interferometers are another.
>>
>>     
>
>
> Jeff is right, BUT, keeping constant phase difference without equal length cables can be challenging. Consider a system I worked on which used phase difference between 7 GHz signals received between two antennas about a meter apart to steer a return beam at 32GHz back the same direction. And, it has to do this while subject to temperature variations from -40 to +80C.
>
>
>
> James Lux, P.E.
> Task Manager, SOMD Software Defined Radios
> Flight Communications Systems Section
> Jet Propulsion Laboratory
> 4800 Oak Grove Drive, Mail Stop 161-213
> Pasadena, CA, 91109
> +1(818)354-2075 phone
> +1(818)393-6875 fax
>
>
> _______________________________________________
>   
However for RF interferometers/bridges the phase differences have to be 
accurately set, a constant phase difference isnt sufficient.

Bruce


From xyzzy at sysabend.org  Fri Oct  3 20:02:15 2008
From: xyzzy at sysabend.org (Tom Arnold)
Date: Fri, 3 Oct 2008 17:02:15 -0700
Subject: [time-nuts] GPS, NTP, and Cisco routers...
In-Reply-To: <mailman.249.1223073977.2205.time-nuts@febo.com>
References: <mailman.249.1223073977.2205.time-nuts@febo.com>
Message-ID: <20081004000215.GK5943@moo.sysabend.org>

On Fri, Oct 03, 2008 at 06:46:17PM -0400, time-nuts-request at febo.com wrote:
> From: Robert Vassar <rvassar at rob-vassar.com>
> Subject: [time-nuts] GPS, NTP, and Cisco routers...
> 
> I've been fiddling around with an old Cisco router here at the house  
> to brush up.  We have an IPv6 project going at work, and our WAN  
> provider provides no native transit, so I'm looking at doing some  
> tunneling.  Anyhow... I discovered IOS 12.1 and above have native NTP  
> capability.  I don't have the exhaustive IOS command reference, and I  
> suspect it's a limited NTP implementation. I'm wondering if it's  
> possible to tie a GPS unit to a router serial port and gain a stratum  
> 0 refclock.
> 
> 
> Any Cisco guru's on the list?  :-)

Cisco routers have a fairly basic NTP capability.  No chance right now of
using the serial port to speak to a GPS or synced clock on 90% of the gear.
I can't say for certain on some of the really high-end stuff but I kinda
doubt it.

Its really only intended for redistribution, heck, you can even *set* what
Stratum you claim to be ( by default I think Cisco uses 8 ).   The only
"extra" features they support is they will do ntp/multicast which is nice
from a client config point of view for us at least.

I'm using a pair of Endrun CDMA based ntp servers because they will work
inside a colo without external antennas, they sync our Cisco cores which
multicast out to the clients.  We're within a few milliseconds which is
close enough.  For redistribution to customers we sync a bunch of unix ntp
servers directly off the CDMA servers so our customers get Stratum 2.  I
hope to be adding a third Endrun box to the mix shortly where I can put up
an external GPS antenna...

-- 
 --------------------------------------------------------------------
 - Tom Arnold           -  "...is it a virus, a drug, or a religion?"  
 - Sysabend Caretaker   -    Juanita Shrugs. "What's the difference?"
 ------------------------       -- Neal Stephenson,  Snow Crash 



From w3kl at w3kl.com  Fri Oct  3 21:00:12 2008
From: w3kl at w3kl.com (Jeffrey Okamitsu)
Date: Fri, 3 Oct 2008 18:00:12 -0700 (PDT)
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <48E6A353.7000503@xtra.co.nz>
Message-ID: <475057.13089.qm@web35402.mail.mud.yahoo.com>

Depending on frequency, achieving the necessary phase matching surely must be achievable electrically or, at microwave frequencies, via a variable length waveguide?
?
I can't imagine that for a precision application one would rely on a coaxial cable maintaining it's length and its other properties.
?
Jeff

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

--- On Fri, 10/3/08, Bruce Griffiths <bruce.griffiths at xtra.co.nz> wrote:

From: Bruce Griffiths <bruce.griffiths at xtra.co.nz>
Subject: Re: [time-nuts] AC Connector On HP 5061B
To: "Discussion of precise time and frequency measurement" <time-nuts at febo.com>
Date: Friday, October 3, 2008, 6:57 PM

Lux, James P wrote:
>   
>> -----Original Message-----
>> From: time-nuts-bounces at febo.com
>> [mailto:time-nuts-bounces at febo.com] On Behalf Of Jeffrey Okamitsu
>> Sent: Friday, October 03, 2008 2:46 PM
>> To: Discussion of precise time and frequency measurement
>> Subject: Re: [time-nuts] AC Connector On HP 5061B
>>
>> For an interferometric application, isn't it sufficient to
>> maintain constant phase difference?
>>
>> Jeff
>>
>> Jeffrey K. Okamitsu, PhD, MBA
>> +1-609-638-5402
>>
>>     
>>> Your absolutely right.  The only two places that I can
>>>       
>> think of, off
>>     
>>> hand, would be televison and RADAR (systems with multiple
>>>       
>> terminals).
>>     
>>> Bill....WB6BNQ
>>>
>>>
>>>       
>> Interferometers are another.
>>
>>     
>
>
> Jeff is right, BUT, keeping constant phase difference without equal length
cables can be challenging. Consider a system I worked on which used phase
difference between 7 GHz signals received between two antennas about a meter
apart to steer a return beam at 32GHz back the same direction. And, it has to do
this while subject to temperature variations from -40 to +80C.
>
>
>
> James Lux, P.E.
> Task Manager, SOMD Software Defined Radios
> Flight Communications Systems Section
> Jet Propulsion Laboratory
> 4800 Oak Grove Drive, Mail Stop 161-213
> Pasadena, CA, 91109
> +1(818)354-2075 phone
> +1(818)393-6875 fax
>
>
> _______________________________________________
>   
However for RF interferometers/bridges the phase differences have to be 
accurately set, a constant phase difference isnt sufficient.

Bruce

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

From w3kl at w3kl.com  Fri Oct  3 21:00:56 2008
From: w3kl at w3kl.com (Jeffrey Okamitsu)
Date: Fri, 3 Oct 2008 18:00:56 -0700 (PDT)
Subject: [time-nuts] AC Connector On HP 5061B
Message-ID: <668968.26331.qm@web35404.mail.mud.yahoo.com>






Depending on frequency, achieving the necessary phase matching surely must be achievable electrically or, at microwave frequencies, via a variable length waveguide?
?
I can't imagine that for a precision application one would rely on a coaxial cable maintaining it's length and its other properties.
?
Jeff

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

--- On Fri, 10/3/08, Bruce Griffiths <bruce.griffiths at xtra.co.nz> wrote:

From: Bruce Griffiths <bruce.griffiths at xtra.co.nz>
Subject: Re: [time-nuts] AC Connector On HP 5061B
To: "Discussion of precise time and frequency measurement" <time-nuts at febo.com>
Date: Friday, October 3, 2008, 6:57 PM

Lux, James P wrote:
>   
>> -----Original Message-----
>> From: time-nuts-bounces at febo.com
>> [mailto:time-nuts-bounces at febo.com] On Behalf Of Jeffrey Okamitsu
>> Sent: Friday, October 03, 2008 2:46 PM
>> To: Discussion of precise time and frequency measurement
>> Subject: Re: [time-nuts] AC Connector On HP 5061B
>>
>> For an interferometric application, isn't it sufficient to
>> maintain constant phase difference?
>>
>> Jeff
>>
>> Jeffrey K. Okamitsu, PhD, MBA
>> +1-609-638-5402
>>
>>     
>>> Your absolutely right.  The only two places that I can
>>>       
>> think of, off
>>     
>>> hand, would be televison and RADAR (systems with multiple
>>>       
>> terminals).
>>     
>>> Bill....WB6BNQ
>>>
>>>
>>>       
>> Interferometers are another.
>>
>>     
>
>
> Jeff is right, BUT, keeping constant phase difference without equal length
cables can be challenging. Consider a system I worked on which used phase
difference between 7 GHz signals received between two antennas about a meter
apart to steer a return beam at 32GHz back the same direction. And, it has to do
this while subject to temperature variations from -40 to +80C.
>
>
>
> James Lux, P.E.
> Task Manager, SOMD Software Defined Radios
> Flight Communications Systems Section
> Jet Propulsion Laboratory
> 4800 Oak Grove Drive, Mail Stop 161-213
> Pasadena, CA, 91109
> +1(818)354-2075 phone
> +1(818)393-6875 fax
>
>
> _______________________________________________
>   
However for RF interferometers/bridges the phase differences have to be 
accurately set, a constant phase difference isnt sufficient.

Bruce

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

From clintjeffrey at optusnet.com.au  Fri Oct  3 21:27:21 2008
From: clintjeffrey at optusnet.com.au (Clint Jeffrey - VK3CSJ)
Date: Sat, 4 Oct 2008 11:27:21 +1000
Subject: [time-nuts] And, for my next trick, 50Hz...link not working
In-Reply-To: <48E67C2C.17795.2723E4C@chris.cheney.tesco.net>
References: <1231b6a80810021741i64d779bj13948680658be749@mail.gmail.com>,
	<48E5E671.9736.29558B@chris.cheney.tesco.net>,
	<1231b6a80810030852jd1d5fdexb9658afbee8c3390@mail.gmail.com>
	<48E67C2C.17795.2723E4C@chris.cheney.tesco.net>
Message-ID: <121FBFC009B148E9A1538F5592D26B2D@ACER5630>

I had the same problem with that link to "FREQUENCY CONTROL PROCESS" but 
then realized that the actual link carried on the next line below, you 
should have some success with the link here, it may still be to long for the 
page width but just copy and paste into your address bar,
if you haven't already done it...

http://www.nationalgrid.com/NR/rdonlyres/4894C7AA-DCD2-4835-9986-57338C31C86A/9922/BC3_i3r18.pdf

Steve Wrote:-
"For some reason I could not get this link down, it just keeps stopping
about a third of the way through"

Cheers

Clint - VK3CSJ 




From XDE-L2G3 at myamail.com  Fri Oct  3 22:28:13 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Fri, 03 Oct 2008 22:28:13 -0400
Subject: [time-nuts] Testing frequency using NTP Bruce GPS ps
References: <mailman.195.1222952732.2205.time-nuts@febo.com>
	<E1KlOmJ-0007rp-88@febo.com> <48E52F08.8070400@xtra.co.nz>
Message-ID: <mailman.7.1223087357.2202.time-nuts@febo.com>


  Bruce Griffiths <bruce.griffiths at xtra.co.nz> wrote:

  >  Mike

  > They actually  use an augmented form of GPS common view  for which
  > the GPS PPS signal and its timing variations are largely common to
  > both locations  and   thus   largely   cancel  when  comparing the
  > frequencies at the customer site with the standards at NIST.

  > With a  good timing receiver (and antenna  location)  the sawtooth
  > corrected PPS signal timing noise can be as low as a few nanosec.

  Is that  like the CNSC02-O1 High Performance PPS system?  From their
  web site, they state:

  "Provides for  dynamic hardware correction of the  1PPS quantization
  ("sawtooth") error.  This reduces the noise on the 1PPS  pulses from
  (typically) +/-27  nsec  (15 nsec 1-sigma) to +/-  11  nsec  (3 nsec
  1-sigma). More importantly, eliminates periods of bias  error caused
  by the quanization error going through a "zero beat" period that can
  last one to two minutes about every 10 minutes or so."

  http://www.cnssys.com/cnsclock/CNSClockII.html

  That paragraph  is  very  interesting.   The  "zero  beat"  error is
  particularly nasty.  I tried to get more information, but  it wasn't
  really clear  how their correction method fixes this  problem. Could
  you explain it a bit more?

  I am working on a new technique that might give one or two orders of
  magnitude improvement  locking  to the 1PPS  signal.  It  might give
  sub-nanosecond locking in a very low cost system. But the  zero beat
  is a  serious  problem,  so  I am interested  to  learn  as  much as
  possible how  other  solutions work. Maybe the simplest  is  to just
  apply some jitter to the GPS crystal oscillator to keep it  off zero
  beat.

  > The "all in view" technique will reduce the noise  contribution to
  > the comparison somewhat.

  That term is a bit confusing. Does it mean using all satellites that
  are in  view, or does it mean the NIST receivers see  the  same ones
  that the user sees?

  > The timestamp  resolution of better than 30ps or  so  ensures that
  > time stamp quantisation noise is negligible.

  > It also  allows, in principle at least, standalone 3  cornered hat
  > comparisons of  the  frequency   instabilities  of  the  3 sources
  > connected to the customer instrument.

  Another term I must study and learn how to do: "3 cornered  hat". It
  sounds like  a very powerful technique, ideally suited for  a fairly
  simple program and some data logging.

  > For more detail see:

  >  http://tf.nist.gov/timefreq/service/fms.htm

  Thanks very  much  for the link. It is curious  they  don't  seem to
  spend much  effort on correcting the user's  frequency  errors. They
  just want to report how much they are off.

  Why is that? You'd think they would perform a more  valuable service
  by applying  advanced techniques to adjust the  user's  equipment to
  minimize the  error, then report and certify the  actual  result. Is
  there some  reason   they   want   to   leave  the  user's equipment
  free-running?

  > Only carrier  phase  GPS  techniques  are  potentially  capable of
  > picosecond noise levels.

  Now we are getting very interesting. How do you do that?

  > However there are a large number of effects that have to  be taken
  > into account and data reduction and correction is very complex.

  What if  we just want to stabilize an oscillator  frequency, without
  caring much  what the exact phase offset is from the USNO?  The high
  carrier frequency  should make it much easier to lock a  rubidium or
  crystal oscillator, and it should give much lower phase noise.

  Of course, auroras and other disturbances would be more significant,
  but here  I'm mainly interested in getting a good  lab  reference to
  measure and compare the performance of other commercial oscillators.

  This is  a  separate  topic, but as long  as  we  are  talking about
  precision signals,  do you happen to know what kind  of distribution
  amplifiers are used at the USNO to distribute the signals from their
  cesium and hydrogen standards?

  www.usno.navy.mil/

  >  Bruce

  Thanks very  much  for  your  help. It  might  seem  like  a  lot of
  questions, but  I'm  pretty sure you will be very  pleased  with the
  results. I think I can beat just about all the other  methods except
  carrier phase techniques.

  Best Regards,

  Mike Monett


From sar10538 at gmail.com  Fri Oct  3 22:36:27 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Sat, 4 Oct 2008 15:36:27 +1300
Subject: [time-nuts] And, for my next trick, 50Hz...link not working
In-Reply-To: <121FBFC009B148E9A1538F5592D26B2D@ACER5630>
References: <1231b6a80810021741i64d779bj13948680658be749@mail.gmail.com>
	<48E5E671.9736.29558B@chris.cheney.tesco.net>
	<1231b6a80810030852jd1d5fdexb9658afbee8c3390@mail.gmail.com>
	<48E67C2C.17795.2723E4C@chris.cheney.tesco.net>
	<121FBFC009B148E9A1538F5592D26B2D@ACER5630>
Message-ID: <1231b6a80810031936je83c9f0gbbcf40419218f33a@mail.gmail.com>

Thanks Clint, it worked this time.

2008/10/4 Clint Jeffrey - VK3CSJ <clintjeffrey at optusnet.com.au>:
> I had the same problem with that link to "FREQUENCY CONTROL PROCESS" but
> then realized that the actual link carried on the next line below, you
> should have some success with the link here, it may still be to long for the
> page width but just copy and paste into your address bar,
> if you haven't already done it...
>
> http://www.nationalgrid.com/NR/rdonlyres/4894C7AA-DCD2-4835-9986-57338C31C86A/9922/BC3_i3r18.pdf
>
> Steve Wrote:-
> "For some reason I could not get this link down, it just keeps stopping
> about a third of the way through"
>
> Cheers
>
> Clint - VK3CSJ
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>



-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From XDE-L2G3 at myamail.com  Fri Oct  3 22:40:17 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Fri, 03 Oct 2008 22:40:17 -0400
Subject: [time-nuts] AC Connector On HP 5061B
References: <c9ffea950810021111s3e3096f1y897ccdc439e7b512@mail.gmail.com>
	<290391.71932.qm@web35406.mail.mud.yahoo.com>
	<c9ffea950810030709v722c5d91v5939ebc6848afe13@mail.gmail.com>
	<002f01c92584$97dc0760$0300a8c0@pc52> <48E68792.3020300@xtra.co.nz>
Message-ID: <mailman.8.1223088055.2202.time-nuts@febo.com>

  Bruce Griffiths <bruce.griffiths at xtra.co.nz> wrote:

  >Tom

  > Another example  of a case where the electrical length of  a cable
  > can be important is in precision frequency distribution systems.

  > Trimming the cable to the right length (one way  propagation delay
  > equal to  an  odd  multiple of half  the  signal  period)  for the
  > frequency in use minimises the effect of load and source mismatch.

  >Bruce

  Bruce,

  Why would it make any difference? It would seem that as long  as the
  cable and connectors are stable, any reflections should be constant,
  and the  signal amplitude and phase should remain  constant.  So the
  zero crossings at the receiver end should not change.

  Where did I go wrong?

  Thanks,

  Mike Monett


From tvb at LeapSecond.com  Fri Oct  3 23:04:17 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Fri, 3 Oct 2008 20:04:17 -0700
Subject: [time-nuts] Testing frequency using NTP Bruce GPS ps
References: <mailman.195.1222952732.2205.time-nuts@febo.com><E1KlOmJ-0007rp-88@febo.com>
	<48E52F08.8070400@xtra.co.nz> <E1KlwtS-0002lT-Ek@febo.com>
Message-ID: <000f01c925cd$e6c84de0$0300a8c0@pc52>

Hi Mike,

Rick's CNSC02-O1 implementation has been discussed here
a number of times over the years (google the archives). It uses
a programmable digital delay line to compensate for the receiver
reported quantization error on each pending 1 pps.

Here's a quick plot of an M12+ receiver without (pink) and
with (yellow) sawtooth correction:

http://www.leapsecond.com/pages/gps4/cns-1pps.gif

No, the correction doesn't handle for the case of prolonged
"zero beat" errors.

As you continue your reading about sawtooth errors see also:
http://www.leapsecond.com/pages/m12/sawtooth.htm
http://www.leapsecond.com/pages/vp/heater.htm
http://www.leapsecond.com/pages/vp/sawtooth.htm
http://www.leapsecond.com/pages/58503-cns2/

/tvb



From wb6bnq at cox.net  Fri Oct  3 23:43:16 2008
From: wb6bnq at cox.net (WB6BNQ)
Date: Fri, 03 Oct 2008 20:43:16 -0700
Subject: [time-nuts] Testing frequency using NTP Bruce GPS ps
References: <mailman.195.1222952732.2205.time-nuts@febo.com>
	<E1KlOmJ-0007rp-88@febo.com> <48E52F08.8070400@xtra.co.nz>
	<E1KlwtS-0002lT-C6@febo.com>
Message-ID: <48E6E654.2F2FD694@cox.net>

Mike Monett wrote:

> > For more detail see:
>
>   >  http://tf.nist.gov/timefreq/service/fms.htm
>
>   Thanks very  much  for the link. It is curious  they  don't  seem to
>   spend much  effort on correcting the user's  frequency  errors. They
>   just want to report how much they are off.
>
>   Why is that? You'd think they would perform a more  valuable service
>   by applying  advanced techniques to adjust the  user's  equipment to
>   minimize the  error, then report and certify the  actual  result. Is
>   there some  reason   they   want   to   leave  the  user's equipment
>   free-running?
>

Mike,

One of the worst perturbations is that of man himself.  Unless one is highly
knowledgeable of the effect of an adjustment, usually the act of the adjustment
is worst then if it had been left alone.

In the world of the "Primary masters," they do not make adjustments, only compare
differences and then report those differences.  Typically, the standards that are
inter compared are of such high quality construction that adjustment is neither
possible nor wanted.

For inter comparisons, a device of known quality is measured before it starts its
journey around the labs, of course it is measured at each lab and then upon
return is measured again at the lab where it all started.  No human adjustment is
ever performed.  This way mostly just environmental factors influence the
portable reference device and much of that can be mitigated with careful record
keeping during its trip.

In the case of the "FMS" you mentioned, the only difference is the devices being
compared are not being moved.  The same methodology still applies however.

Bill....WB6BNQ




From didier at cox.net  Fri Oct  3 23:50:12 2008
From: didier at cox.net (Didier Juges)
Date: Fri, 3 Oct 2008 22:50:12 -0500
Subject: [time-nuts] Testing frequency using NTP Bruce GPS ps
In-Reply-To: <48E6E654.2F2FD694@cox.net>
References: <mailman.195.1222952732.2205.time-nuts@febo.com><E1KlOmJ-0007rp-88@febo.com>
	<48E52F08.8070400@xtra.co.nz><E1KlwtS-0002lT-C6@febo.com>
	<48E6E654.2F2FD694@cox.net>
Message-ID: <0E274E510BD149D6A26CD0952F789A52@didierhp>

I suspect another reason is that even if it were adjusted, a user's
individual standard would still deviate from the NIST average standard, and
the drift would have to be accounted for anyhow, so what's the point of
attempting to mess with it and take the risk of loosing the data accumulated
so far? (the fact of readjusting a standard, if such adjustment is even
possible, invalidates much of the data collected up to that point.)

Didier KO4BB

> -----Original Message-----
> From: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] On Behalf Of WB6BNQ
> Sent: Friday, October 03, 2008 10:43 PM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Testing frequency using NTP Bruce GPS ps
> 
> Mike Monett wrote:
> 
> > > For more detail see:
> >
> >   >  http://tf.nist.gov/timefreq/service/fms.htm
> >
> >   Thanks very  much  for the link. It is curious  they  
> don't  seem to
> >   spend much  effort on correcting the user's  frequency  
> errors. They
> >   just want to report how much they are off.
> >
> >   Why is that? You'd think they would perform a more  
> valuable service
> >   by applying  advanced techniques to adjust the  user's  
> equipment to
> >   minimize the  error, then report and certify the  actual  
> result. Is
> >   there some  reason   they   want   to   leave  the  
> user's equipment
> >   free-running?
> >
> 
> Mike,
> 
> One of the worst perturbations is that of man himself.  
> Unless one is highly knowledgeable of the effect of an 
> adjustment, usually the act of the adjustment is worst then 
> if it had been left alone.
> 
> In the world of the "Primary masters," they do not make 
> adjustments, only compare differences and then report those 
> differences.  Typically, the standards that are inter 
> compared are of such high quality construction that 
> adjustment is neither possible nor wanted.
> 
> For inter comparisons, a device of known quality is measured 
> before it starts its journey around the labs, of course it is 
> measured at each lab and then upon return is measured again 
> at the lab where it all started.  No human adjustment is ever 
> performed.  This way mostly just environmental factors 
> influence the portable reference device and much of that can 
> be mitigated with careful record keeping during its trip.
> 
> In the case of the "FMS" you mentioned, the only difference 
> is the devices being compared are not being moved.  The same 
> methodology still applies however.
> 
> Bill....WB6BNQ
> 
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com To unsubscribe, 
> go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.



From XDE-L2G3 at myamail.com  Sat Oct  4 00:13:46 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Sat, 04 Oct 2008 00:13:46 -0400
Subject: [time-nuts] Testing frequency using NTP Bruce GPS ps
References: <mailman.195.1222952732.2205.time-nuts@febo.com>
	<E1KlOmJ-0007rp-88@febo.com> <48E52F08.8070400@xtra.co.nz>
	<E1KlwtS-0002lT-Ek@febo.com> <000f01c925cd$e6c84de0$0300a8c0@pc52>
Message-ID: <mailman.9.1223093671.2202.time-nuts@febo.com>

  "Tom Van Baak" <tvb at LeapSecond.com> wrote:

  >Hi Mike,

  Hi Tom,

  I want  to thank you for the very nice reply you gave to my  email a
  while ago.  Unfortunately,  I   am  still  learning  about precision
  frequency references, and I don't have enough knowledge yet  to give
  you an  intelligent  reply, or even ask a sensible  question.  But I
  will as soon as possible.

  In the  meantime,  your site is invaluable  for  newcomers  like me.
  Thank you very much for taking the time to organize it so well.

  > Rick's CNSC02-O1  implementation has been discussed here  a number
  > of times  over  the  years   (google   the  archives).  It  uses a
  > programmable digital  delay  line to compensate  for  the receiver
  > reported quantization error on each pending 1 pps.

  The single-shot is supposed to eliminate the 1PPS jitter? So it must
  be triggered on the 1PPS, and the variable delay gives an average of
  half the clock period?

  Thanks for the tip. I'll research the archives and see if I can some
  up with some better understanding of how it works.

  > Here's a  quick plot of an M12+ receiver without  (pink)  and with
  > (yellow) sawtooth correction:

  >http://www.leapsecond.com/pages/gps4/cns-1pps.gif

  Thanks. I had not found that page yet. Just judging by  eyeball, the
  pink and yellow traces don't seem to track very well. Any reason?

  And what's the blue trace for? I can't seem to find the parent page,
  so I don't know if you have already explained it.

  > No, the correction doesn't handle for the case of  prolonged "zero
  > beat" errors.

  > As you continue your reading about sawtooth errors see also:

  >http://www.leapsecond.com/pages/m12/sawtooth.htm

  Yes, I had found that page. The top graphs make me believe my method
  will work fine.

  The bottom graphs say it won't:)

  >http://www.leapsecond.com/pages/vp/heater.htm

  Yes, that page is also very encouraging. All I have to do  is figure
  out how to close the loop on a long delay in the feedback. I believe
  the PRS10 can average up to 8 hours, so it should be possible.

  >http://www.leapsecond.com/pages/vp/sawtooth.htm

  Yes, Yes,  Yes.  I had found that page. It  is  very  important. The
  uniform distribution in the top graph says my method will work.

  The bottom  graph  looks very similar to ones I  got  from measuring
  jitter on  hard disk drives back in the 80's. The  graph  contains a
  great deal  of  information on what is happening  in  the read/write
  channel, head/media  magnetics,  servo  system,  and  external noise
  sources. As  soon  as I saw that, I wondered if  a  similar analysis
  method might work in this case.

  >http://www.leapsecond.com/pages/58503-cns2/

  Thank you very much. That page has a lot of very good information. I
  like the way you take data and present it. The data is  exactly what
  is needed  to illustrate an issue, and the presentation  is  so very
  clear that anyone should understand it.

  Overall, I was a little disappointed to find the sawtooth correction
  only gives about a factor of 3 or so improvement. The results I have
  obtained with  my  method have given over  two  orders  of magnitude
  improvement in noise reduction. That's with no optimization.

  But this  is a new area, and there is a lot to learn  about  what is
  going on. So I am very anxious to get my hands on some equipment and
  start developing  the  necessary   circuits.  They  are  really very
  simple. Anyone should be able to do it with no problem.

  I just got from eBay an HP 8566A, an HP 53310A including  the 53305A
  Phase Analysis  software,  an  HP 3456A, two  TEK  2467's,  and some
  National Instuments AT-GPIB / TNT cards with cables and drivers. The
  Win98 drivers for the NI were courtesy of a poster on  the TekScopes
  forum, and  I  uploaded them to Didier's site  for  anyone  else who
  might be interested.

  My big  problem right now is none of my working  computers  have any
  ISA slots for the GPIB. I have some old motherboards with ISA slots,
  but no software drivers to get the motherboard working.

  And, of  course,  I have to get a TBolt and  a  rubidium oscillator.
  Hopefully that's the next step.

  >/tvb

  Thanks,

  Mike Monett


From donw at engineeringinc.com  Sat Oct  4 00:17:16 2008
From: donw at engineeringinc.com (Don E. Wisdom)
Date: Fri, 3 Oct 2008 22:17:16 -0600
Subject: [time-nuts] Truetime Time server NTS-100 Downconverter info wanted
Message-ID: <C50C4A6C.47C8%donw@engineeringinc.com>

Hi All,
I have a NTS-100 GPS model.   I am going to be putting it into use @ my
employers where I have a T1 & Rooftop access & backup power.   It has the
lovely "downconverter required" sticker on the back of it.   It does NOT
like my trimble bullet antenna.   Can someone let me know how I can get this
working with a Andrews GPS antenna?
Thanks
--Don




From bruce.griffiths at xtra.co.nz  Sat Oct  4 01:09:31 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Sat, 04 Oct 2008 18:09:31 +1300
Subject: [time-nuts] AC Connector On HP 5061B
In-Reply-To: <E1Klx4i-00035H-EH@febo.com>
References: <c9ffea950810021111s3e3096f1y897ccdc439e7b512@mail.gmail.com>	<290391.71932.qm@web35406.mail.mud.yahoo.com>	<c9ffea950810030709v722c5d91v5939ebc6848afe13@mail.gmail.com>	<002f01c92584$97dc0760$0300a8c0@pc52>
	<48E68792.3020300@xtra.co.nz> <E1Klx4i-00035H-EH@febo.com>
Message-ID: <48E6FA8B.4020102@xtra.co.nz>

Mike Monett wrote:
>   Bruce Griffiths <bruce.griffiths at xtra.co.nz> wrote:
>
>   >Tom
>
>   > Another example  of a case where the electrical length of  a cable
>   > can be important is in precision frequency distribution systems.
>
>   > Trimming the cable to the right length (one way  propagation delay
>   > equal to  an  odd  multiple of half  the  signal  period)  for the
>   > frequency in use minimises the effect of load and source mismatch.
>
>   >Bruce
>
>   Bruce,
>
>   Why would it make any difference? It would seem that as long  as the
>   cable and connectors are stable, any reflections should be constant,
>   and the  signal amplitude and phase should remain  constant.  So the
>   zero crossings at the receiver end should not change.
>
>   Where did I go wrong?
>
>   Thanks,
>
>   Mike Monett
>
>   
Mike

see:
http://ad.usno.navy.mil/edboard/070518p.pdf

Bruce


From bruce.griffiths at xtra.co.nz  Sat Oct  4 02:34:41 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Sat, 04 Oct 2008 19:34:41 +1300
Subject: [time-nuts] Testing frequency using NTP Bruce GPS ps
In-Reply-To: <E1KlwtS-0002lT-QG@febo.com>
References: <mailman.195.1222952732.2205.time-nuts@febo.com>	<E1KlOmJ-0007rp-88@febo.com>
	<48E52F08.8070400@xtra.co.nz> <E1KlwtS-0002lT-QG@febo.com>
Message-ID: <48E70E81.9050203@xtra.co.nz>

Mike Monett wrote:
>   Bruce Griffiths <bruce.griffiths at xtra.co.nz> wrote:
>
>   >  Mike
>
>   > They actually  use an augmented form of GPS common view  for which
>   > the GPS PPS signal and its timing variations are largely common to
>   > both locations  and   thus   largely   cancel  when  comparing the
>   > frequencies at the customer site with the standards at NIST.
>
>   > With a  good timing receiver (and antenna  location)  the sawtooth
>   > corrected PPS signal timing noise can be as low as a few nanosec.
>
>   Is that  like the CNSC02-O1 High Performance PPS system?  From their
>   web site, they state:
>
>   "Provides for  dynamic hardware correction of the  1PPS quantization
>   ("sawtooth") error.  This reduces the noise on the 1PPS  pulses from
>   (typically) +/-27  nsec  (15 nsec 1-sigma) to +/-  11  nsec  (3 nsec
>   1-sigma). More importantly, eliminates periods of bias  error caused
>   by the quanization error going through a "zero beat" period that can
>   last one to two minutes about every 10 minutes or so."
>
>   http://www.cnssys.com/cnsclock/CNSClockII.html
>
>   That paragraph  is  very  interesting.   The  "zero  beat"  error is
>   particularly nasty.  I tried to get more information, but  it wasn't
>   really clear  how their correction method fixes this  problem. Could
>   you explain it a bit more?
>
>   
The GPS receiver can only position the leading edge of the PPS pilse to 
the nearest transition of the receiver crystal oscillator or harmonic 
thereof.
However it can estimate the resultant timing error with a resolution of 
1ns (for the M12 GPS timing receiver and its derivatives).
The resultant sawtooth error can either be corrected in hardware as in 
the CNSClockII or it can be corrected in software (if the PPS transition 
is time stamped with sufficient precision).
The NIST system has a time stamp resolution of 30ps or so software 
correction for sawtooth error is possible.
After sawtooth correction their is still some residual, largely random, 
noise of a few ns rms with a well sited antenna.
>   I am working on a new technique that might give one or two orders of
>   magnitude improvement  locking  to the 1PPS  signal.  It  might give
>   sub-nanosecond locking in a very low cost system. But the  zero beat
>   is a  serious  problem,  so  I am interested  to  learn  as  much as
>   possible how  other  solutions work. Maybe the simplest  is  to just
>   apply some jitter to the GPS crystal oscillator to keep it  off zero
>   beat.
>
>   > The "all in view" technique will reduce the noise  contribution to
>   > the comparison somewhat.
>
>   That term is a bit confusing. Does it mean using all satellites that
>   are in  view, or does it mean the NIST receivers see  the  same ones
>   that the user sees?
>
>   
Common view means that the 2 GPS timing receivers use the same GPS SV 
for timing purposes.
Observing schedules have to be agree upon before hand.
This technique originated with early receivers that could only track one 
SV at a time.

All in view means that each GPS receiver use all SVs that it can see to 
derive its timing.
With modern timing receivers sufficient information can be logged so 
that the timing info from each individual SV can be extracted from the 
PPS time stamp sequence if desired.

>   > The timestamp  resolution of better than 30ps or  so  ensures that
>   > time stamp quantisation noise is negligible.
>
>   > It also  allows, in principle at least, standalone 3  cornered hat
>   > comparisons of  the  frequency   instabilities  of  the  3 sources
>   > connected to the customer instrument.
>
>   Another term I must study and learn how to do: "3 cornered  hat". It
>   sounds like  a very powerful technique, ideally suited for  a fairly
>   simple program and some data logging.
>
>   
It is if and only if the  phase variations of 3 (or more ) oscillators 
are statistically independent.
It is then possible to derive the individual phase variances of each 
oscillator from the the 3 (or 0.5*N*(N-1) for N oscillators) sets of 
phase difference measurements between pairs of oscillators.
In practice all oscillators may share the same ambient thermal 
environment so that their finite oven gains will produce small cross 
variance terms.
Even humidity and atmospheric pressure variations may affect the 
frequency of an OCXO.
>   > For more detail see:
>
>   >  http://tf.nist.gov/timefreq/service/fms.htm
>
>   Thanks very  much  for the link. It is curious  they  don't  seem to
>   spend much  effort on correcting the user's  frequency  errors. They
>   just want to report how much they are off.
>
>   Why is that? You'd think they would perform a more  valuable service
>   by applying  advanced techniques to adjust the  user's  equipment to
>   minimize the  error, then report and certify the  actual  result. Is
>   there some  reason   they   want   to   leave  the  user's equipment
>   free-running?
>
>   > Only carrier  phase  GPS  techniques  are  potentially  capable of
>   > picosecond noise levels.
>
>   Now we are getting very interesting. How do you do that?
>   
Most GPS receivers track the carrier phase variations internally.
Some make it available to the user (eg. Novatel Superstar GPS receivers, 
Rockwell/Navman Jupiter GPS receivers ).
However since these refer to the phase variations between the GPS 
carrier and the receiver LO, they are usually only useful if the 
receiver LO is phase locked to the OCXO output frequency.

>   > However there are a large number of effects that have to  be taken
>   > into account and data reduction and correction is very complex.
>
>   What if  we just want to stabilize an oscillator  frequency, without
>   caring much  what the exact phase offset is from the USNO?  The high
>   carrier frequency  should make it much easier to lock a  rubidium or
>   crystal oscillator, and it should give much lower phase noise.
>
>   
There are commercial carrier phase disciplined oscillators available (eg 
from Quartzlock) if you can afford them.
One of these purports to have better short to medium term stability than 
a passive hydrogen maser.
>   Of course, auroras and other disturbances would be more significant,
>   but here  I'm mainly interested in getting a good  lab  reference to
>   measure and compare the performance of other commercial oscillators.
>
>   This is  a  separate  topic, but as long  as  we  are  talking about
>   precision signals,  do you happen to know what kind  of distribution
>   amplifiers are used at the USNO to distribute the signals from their
>   cesium and hydrogen standards?
>
>   www.usno.navy.mil/
>
>   
No idea, as they don't say but the Spectradynamics amplifiers are used 
by national standards labs in several countries.
>   >  Bruce
>
>   Thanks very  much  for  your  help. It  might  seem  like  a  lot of
>   questions, but  I'm  pretty sure you will be very  pleased  with the
>   results. I think I can beat just about all the other  methods except
>   carrier phase techniques.
>
>   Best Regards,
>
>   Mike Monett
>
>   
Bruce



From tvb at LeapSecond.com  Sat Oct  4 03:28:49 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Sat, 4 Oct 2008 00:28:49 -0700
Subject: [time-nuts] Testing frequency using NTP Bruce GPS ps
References: <mailman.195.1222952732.2205.time-nuts@febo.com><E1KlOmJ-0007rp-88@febo.com>
	<48E52F08.8070400@xtra.co.nz><E1KlwtS-0002lT-Ek@febo.com>
	<000f01c925cd$e6c84de0$0300a8c0@pc52> <E1KlyXH-0004HB-SC@febo.com>
Message-ID: <005401c925f2$db402fe0$0300a8c0@pc52>

>  The single-shot is supposed to eliminate the 1PPS jitter? So it must
>  be triggered on the 1PPS, and the variable delay gives an average of
>  half the clock period?

Yes, right.

Note another equivalent technique is to use two serial ports;
one for the receiver (record sawtooth corrections) and one
for a 53132A-style counter (record TI measurements) and
then do the calculations in software. TAC32 does this. I think
TBoltMon also allows it. Roughly, it's a trade-off in equipment
and complexity. They give essentially the same performance
result.

There are still many other sources of noise, both short- and
long-term in an OEM GPS receiver/antenna system. That's
why even if there were zero quantization error, you would
still see a couple of ns rms error in the 1PPS output.

>  Thanks. I had not found that page yet. Just judging by  eyeball, the
>  pink and yellow traces don't seem to track very well. Any reason?

On that plot, the various runs weren't concurrent so you can't
look for common-mode effects. Separate runs, showing typical
levels of jitter, all plotted on the same x-y scale. You've got a
good eye.

>  And what's the blue trace for? I can't seem to find the parent page,
>  so I don't know if you have already explained it.

This will help a bit more:
http://www.febo.com/pipermail/time-nuts/2005-April/018114.html

>  Overall, I was a little disappointed to find the sawtooth correction
>  only gives about a factor of 3 or so improvement. The results I have

That's partly because the sawtooth of the M12+ is small to
begin with, at least compared to the earlier VP. So there
isn't much room for sawtooth correction to have a massive
gain. Also the granularity of the quantization message from
the receiver is 1 ns. And there's an internal delay of one or
two seconds which has a slight effect on the quality of the
correction.

Another way to look at it is this. If a perfect M12+ had, say,
2.5 ns of jitter, and you saw 10 ns rms without sawtooth
correction and 3 ns rms with sawtooth correction you could
say you achieved a 15x improvement! (10-2.5)/(3-2.5). Or if
you didn't say it, the marketing department certainly would.

The closer you get to a few nanoseconds of jitter anyway,
the more all the other errors in a typical cheap OEM GPS
receiver and antenna system come into play. So once you
average beyond a couple of minutes the wander you see in
the 1PPS has less and less to do with sawtooth and more to
do with the sum of all the other subtle errors.

Expensive geodetic or timing receivers use an assortment
of techniques to reduce the effect of these remaining error
sources, to the point where you'll hear of millimeters and
picoseconds (and priced accordingly).

>  obtained with  my  method have given over  two  orders  of magnitude
>  improvement in noise reduction. That's with no optimization.

Averaging over multiple samples, of course, gives a reduction
in noise. You can see this in the ADEV plots at the end of:
http://www.leapsecond.com/pages/58503-cns2/

On the other hand, if you found a way to get two orders of
magnitude better performance out of an M12+ without the
use of averaging then I'm all ears.

/tvb



From sar10538 at gmail.com  Sat Oct  4 06:10:49 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Sat, 4 Oct 2008 23:10:49 +1300
Subject: [time-nuts] And, for my next trick, 50Hz
In-Reply-To: <48E67A0A.5090303@xtra.co.nz>
References: <1231b6a80810021741i64d779bj13948680658be749@mail.gmail.com>
	<001301c924f2$511ed330$0300a8c0@pc52>
	<1231b6a80810022029t676bdcb7k1479ef0ad195ee1d@mail.gmail.com>
	<002401c9250f$76694f40$0300a8c0@pc52>
	<1231b6a80810030952o2f33a8a6ubf9d5bdb108668a7@mail.gmail.com>
	<1231b6a80810031018i2f8b005ah1045fa7547db1524@mail.gmail.com>
	<48E67A0A.5090303@xtra.co.nz>
Message-ID: <1231b6a80810040310g28a3798agbd2b11c040b7fa71@mail.gmail.com>

2008/10/4 Bruce Griffiths <bruce.griffiths at xtra.co.nz>:

> With interpolation you dont need to slow the signal transitions too much.
> A transition suficient to allow 3 or 4 samples to be taken during the
> transition is adequate.
> If the signal slew rate is too slow sound card input noise and the
> finite ADC resolution will increase the measuremnet noise.

OK, I understand what you mean. Guess it will have to slewed somewhat
to try and get the 3 to 4 samples on a rising/falling edge though. If
we are looking at a 1KHz signal and sampling at 44KHz, that means we
have to slew the transition to something like 100us to guarantee
getting enough samples during the edge. So that is a 1/10 of the input
signal or a roll-off of 10khz. That happens to fall nicely inside the
bandwidth of the sound card.

So how do we time-stamp these samples considering they will be
buffered by the card and not read independently. Perhaps we don't have
to as we can read each buffer when it it is full and time-stamp at
that point. We know that each sample is taken at 44KHz and can easily
count the sample number to calculate the time.

I'll have a look at this and see what I get. I really need to check it
against a known standard so will solve that problem first but this
would be an interesting way of using a PC to check frequency.

73
Steve

-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From sar10538 at gmail.com  Sat Oct  4 06:37:54 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Sat, 4 Oct 2008 23:37:54 +1300
Subject: [time-nuts] And, for my next trick, 50Hz
In-Reply-To: <48E67C2C.17795.2723E4C@chris.cheney.tesco.net>
References: <1231b6a80810021741i64d779bj13948680658be749@mail.gmail.com>
	<48E5E671.9736.29558B@chris.cheney.tesco.net>
	<1231b6a80810030852jd1d5fdexb9658afbee8c3390@mail.gmail.com>
	<48E67C2C.17795.2723E4C@chris.cheney.tesco.net>
Message-ID: <1231b6a80810040337y17684d41j304f7f8d8c0a5d9d@mail.gmail.com>

2008/10/4 Chris Cheney <chris.cheney at tesco.net>:

> I don't have a problem with the page (using either Firefox or IE). FWIW
> here is the whole of the relevant paragraph

I finally have a copy of the document now, thanks.

> BC3.4.3 Electric Time
> NGET will endeavour (in so far as it is able) to control electric clock
> time to within
> plus or minus 10 seconds by specifying changes to Target Frequency, by
> accepting bids and offers in the Balancing Mechanism. Errors greater than
> plus
> or minus 10 seconds may be temporarily accepted at NGET's reasonable
> discretion.
>
> I believe that they are saying that the accumulated phase error will
> normally be less than 10 seconds worth, but that amount of phase error
> may exist indefinitely.

I am not so sure as to what sector this document refers to as it is a
bit out of context but there seems to be no reference to the period
over which these 10 seconds can differ and if that is accumulative or
not.

73
Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From bruce.griffiths at xtra.co.nz  Sat Oct  4 06:38:07 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Sat, 04 Oct 2008 23:38:07 +1300
Subject: [time-nuts] And, for my next trick, 50Hz
In-Reply-To: <1231b6a80810040310g28a3798agbd2b11c040b7fa71@mail.gmail.com>
References: <1231b6a80810021741i64d779bj13948680658be749@mail.gmail.com>	<001301c924f2$511ed330$0300a8c0@pc52>	<1231b6a80810022029t676bdcb7k1479ef0ad195ee1d@mail.gmail.com>	<002401c9250f$76694f40$0300a8c0@pc52>	<1231b6a80810030952o2f33a8a6ubf9d5bdb108668a7@mail.gmail.com>	<1231b6a80810031018i2f8b005ah1045fa7547db1524@mail.gmail.com>	<48E67A0A.5090303@xtra.co.nz>
	<1231b6a80810040310g28a3798agbd2b11c040b7fa71@mail.gmail.com>
Message-ID: <48E7478F.4010005@xtra.co.nz>

Steve Rooke wrote:
> 2008/10/4 Bruce Griffiths <bruce.griffiths at xtra.co.nz>:
>
>   
>> With interpolation you dont need to slow the signal transitions too much.
>> A transition suficient to allow 3 or 4 samples to be taken during the
>> transition is adequate.
>> If the signal slew rate is too slow sound card input noise and the
>> finite ADC resolution will increase the measuremnet noise.
>>     
>
> OK, I understand what you mean. Guess it will have to slewed somewhat
> to try and get the 3 to 4 samples on a rising/falling edge though. If
> we are looking at a 1KHz signal and sampling at 44KHz, that means we
> have to slew the transition to something like 100us to guarantee
> getting enough samples during the edge. So that is a 1/10 of the input
> signal or a roll-off of 10khz. That happens to fall nicely inside the
> bandwidth of the sound card.
>
> So how do we time-stamp these samples considering they will be
> buffered by the card and not read independently. Perhaps we don't have
> to as we can read each buffer when it it is full and time-stamp at
> that point. We know that each sample is taken at 44KHz and can easily
> count the sample number to calculate the time.
>
> I'll have a look at this and see what I get. I really need to check it
> against a known standard so will solve that problem first but this
> would be an interesting way of using a PC to check frequency.
>
> 73
> Steve
>
>   
Steve

Such interpolation is more effective when one channel has a reference 
signal input (eg PPS or a known frequency) and the other channel has the 
frequency to be measured.

Bruce



From sar10538 at gmail.com  Sat Oct  4 06:51:20 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Sat, 4 Oct 2008 23:51:20 +1300
Subject: [time-nuts] And, for my next trick, 50Hz
In-Reply-To: <48E7478F.4010005@xtra.co.nz>
References: <1231b6a80810021741i64d779bj13948680658be749@mail.gmail.com>
	<001301c924f2$511ed330$0300a8c0@pc52>
	<1231b6a80810022029t676bdcb7k1479ef0ad195ee1d@mail.gmail.com>
	<002401c9250f$76694f40$0300a8c0@pc52>
	<1231b6a80810030952o2f33a8a6ubf9d5bdb108668a7@mail.gmail.com>
	<1231b6a80810031018i2f8b005ah1045fa7547db1524@mail.gmail.com>
	<48E67A0A.5090303@xtra.co.nz>
	<1231b6a80810040310g28a3798agbd2b11c040b7fa71@mail.gmail.com>
	<48E7478F.4010005@xtra.co.nz>
Message-ID: <1231b6a80810040351vc8327c6o72df2d6559445955@mail.gmail.com>

2008/10/4 Bruce Griffiths <bruce.griffiths at xtra.co.nz>:
>
> Such interpolation is more effective when one channel has a reference
> signal input (eg PPS or a known frequency) and the other channel has the
> frequency to be measured.

Agreed but the original idea was to measure frequency without a local
freq standard. If we have a local standard, it can be fed into the
time-base of any cheap counter to get accurate results. The idea was
to use a remote standard via NTP, synced and traceable to external
atomic standards, to achieve a reasonable degree of accuracy.

73
Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From weyster at cfl.rr.com  Sat Oct  4 11:51:03 2008
From: weyster at cfl.rr.com (Hank)
Date: Sat, 4 Oct 2008 11:51:03 -0400
Subject: [time-nuts] THUNBERBOLT PACKET 0X8F-AB
Message-ID: <DC4DF393EB984033BD9773A2288FF160@whe7d219f70f9a>

While writing my own software to display time and other status information, I have noticed a very strange item when packet 0x8F-AB is being sent out.
Normally this packet has 17 bytes with 0XAB  being byte 0

While the time is being displayed by the new software, I noticed that every time the seconds reached 16 the display would be incorrect.  Wrote a special test routine, and there is an extra byte being sent by the Thunderbolt ( firmware REV E ) only for the packet that has seconds equal to 16.  ( 16 or 10h ) is send twice !!

Has anyone that is writing display software seen this or any other problem in the formats ?

I also verified this issue using Procom terminal software that has a monitor window and captures the data in HEX format !!

Hank

From k1ggi at arrl.net  Sat Oct  4 12:33:38 2008
From: k1ggi at arrl.net (Ed, k1ggi)
Date: Sat, 4 Oct 2008 12:33:38 -0400
Subject: [time-nuts] THUNBERBOLT PACKET 0X8F-AB
In-Reply-To: <DC4DF393EB984033BD9773A2288FF160@whe7d219f70f9a>
References: <DC4DF393EB984033BD9773A2288FF160@whe7d219f70f9a>
Message-ID: <042c01c9263e$f539e610$0a01a8c0@ATHLONXP1700>

That would be the 'byte stuffing' inherent in TSIP packet structure.

From scmcgrath at gmail.com  Sat Oct  4 21:16:12 2008
From: scmcgrath at gmail.com (Scott McGrath)
Date: Sat, 4 Oct 2008 21:16:12 -0400
Subject: [time-nuts] GPS, NTP, and Cisco routers...
In-Reply-To: <3C932D37-8120-4833-81D8-9AC8C1E73434@rob-vassar.com>
References: <3C932D37-8120-4833-81D8-9AC8C1E73434@rob-vassar.com>
Message-ID: <c9ffea950810041816v23045daeu5282791badfe74de@mail.gmail.com>

What do you need to know about NTP on IOS? - I've been working with
Cisco gear longer than I care to admit and have a bunch of CC*
certifications but that's not relevant here

Generally IOS devices actually speak SNTP - Not sure whether they can
use an external reference clock I don't think so BUT it might be
possible to replace the cheap TCXO universally used by cisco with a
buffer circuit and derive your clock from there and configure the
device as a ntp server.    Let me peek inside one of the routers
hanging around here and I'll see what can be done

- Scott


On Fri, Oct 3, 2008 at 5:39 PM, Robert Vassar <rvassar at rob-vassar.com> wrote:
>
>
>
> I've been fiddling around with an old Cisco router here at the house
> to brush up.  We have an IPv6 project going at work, and our WAN
> provider provides no native transit, so I'm looking at doing some
> tunneling.  Anyhow... I discovered IOS 12.1 and above have native NTP
> capability.  I don't have the exhaustive IOS command reference, and I
> suspect it's a limited NTP implementation. I'm wondering if it's
> possible to tie a GPS unit to a router serial port and gain a stratum
> 0 refclock.
>
>
> Any Cisco guru's on the list?  :-)
>
>
>
> Cheers,
>
> Rob
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>


From scmcgrath at gmail.com  Sat Oct  4 21:25:45 2008
From: scmcgrath at gmail.com (Scott McGrath)
Date: Sat, 4 Oct 2008 21:25:45 -0400
Subject: [time-nuts] Truetime Time server NTS-100 Downconverter info
	wanted
In-Reply-To: <C50C4A6C.47C8%donw@engineeringinc.com>
References: <C50C4A6C.47C8%donw@engineeringinc.com>
Message-ID: <c9ffea950810041825i78442a21g887d3f2abf9bdcc3@mail.gmail.com>

We have the time vault units - soon to be replaced with 3500's with Rb
Oscillators.

The 'downconverter' is an amplifier used for long cable runs and the
power injection is changed as well.    I would measure what the
NTS-100 is actually putting out without the downconverter our
NTS-300/TimeVault unit puts +12 on the cable it may be much higher for
the downconverter.    There are some TrueTime upconverters on EBAY
right now which should do the job

- Scott




On Sat, Oct 4, 2008 at 12:17 AM, Don E. Wisdom <donw at engineeringinc.com> wrote:
> Hi All,
> I have a NTS-100 GPS model.   I am going to be putting it into use @ my
> employers where I have a T1 & Rooftop access & backup power.   It has the
> lovely "downconverter required" sticker on the back of it.   It does NOT
> like my trimble bullet antenna.   Can someone let me know how I can get this
> working with a Andrews GPS antenna?
> Thanks
> --Don
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>


From kirbybq at bellsouth.net  Sun Oct  5 00:40:00 2008
From: kirbybq at bellsouth.net (Brian Kirby)
Date: Sat, 04 Oct 2008 23:40:00 -0500
Subject: [time-nuts] GPIB Card
Message-ID: <48E84520.7070403@bellsouth.net>

A friend has given me a GPIB card and neither of us know who made it.

First its a standard ISA card and it has a GPIB female plug on the rear. 
    No manufacturer or model number but there is a symbol of a tree on 
the rear (maybe paradise?) and beside is 6323706 rev A 667523.  Made in 
the USA and another number in a corner is 94V-0.

On the chip side of the board it appears to have a NEC controller marked 
big letters D7210C little letters 8308PB.  An assembly number of 6323705 
rev A.  Has another 20 other 74LSxx  glue logic ICs...Card is about 4.5 
inches by 4.25 inches.

Has 5 set of berg pins, one set is A13, A14, next set is 2FX and IE, 
next set is computer IRQs 2 thru 7, then a DRQ1-DAC1-DRQ3-DAC3, then 
last set of DAC2 and DRO2.

It had a 1.44 Mb floppy which suscessfully copied, three files; 
config.sys , DV488PC.sys, and LVDT.C

Config.sys shows:
BREAK=ON
BUFFERS=20
FILES=30
LASTDRIVE=E
SHELL=C:\DOS\COMMAND.COM /P /E:256
DEVICE=C:\DOS\ANSI.SYS
DEVICE=C:\VIPARSE.SYS
INSTALL=C:\DOS\FASTOPEN.EXE C:=(50,25)
DEVICE=C:\DV488PC.SYS

LVDT.C is "C" code for
for a program written by  a NASA/MSFC employee for the calibration
of Linear Displacement trunsducers...

Does anybody in the list have an idea of who made the card ?  I'm 
researching to see if it is still usable....


Brian - KD4FM




From fortime at bellsouth.net  Sun Oct  5 00:41:59 2008
From: fortime at bellsouth.net (phil)
Date: Sun, 5 Oct 2008 00:41:59 -0400
Subject: [time-nuts] Truetime Time server NTS-100 Downconverter
	infowanted
References: <C50C4A6C.47C8%donw@engineeringinc.com>
	<c9ffea950810041825i78442a21g887d3f2abf9bdcc3@mail.gmail.com>
Message-ID: <000a01c926a4$b4958680$a101a8c0@officemail>

Might it be possible a word of caution is in order?
Was not a "downconverter" used with the old GOES (L-band) Truetime satellite 
equipment. That would not be the same as the down converters used on gps. 
Just a thought.
Phil


----- Original Message ----- 
From: "Scott McGrath" <scmcgrath at gmail.com>
To: "Discussion of precise time and frequency measurement" 
<time-nuts at febo.com>
Sent: Saturday, October 04, 2008 9:25 PM
Subject: Re: [time-nuts] Truetime Time server NTS-100 Downconverter 
infowanted


> We have the time vault units - soon to be replaced with 3500's with Rb
> Oscillators.
>
> The 'downconverter' is an amplifier used for long cable runs and the
> power injection is changed as well.    I would measure what the
> NTS-100 is actually putting out without the downconverter our
> NTS-300/TimeVault unit puts +12 on the cable it may be much higher for
> the downconverter.    There are some TrueTime upconverters on EBAY
> right now which should do the job
>
> - Scott
>
>
>
>
> On Sat, Oct 4, 2008 at 12:17 AM, Don E. Wisdom <donw at engineeringinc.com> 
> wrote:
>> Hi All,
>> I have a NTS-100 GPS model.   I am going to be putting it into use @ my
>> employers where I have a T1 & Rooftop access & backup power.   It has the
>> lovely "downconverter required" sticker on the back of it.   It does NOT
>> like my trimble bullet antenna.   Can someone let me know how I can get 
>> this
>> working with a Andrews GPS antenna?
>> Thanks
>> --Don
>>
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to 
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there. 



From donw at engineeringinc.com  Sun Oct  5 00:43:11 2008
From: donw at engineeringinc.com (Don E. Wisdom)
Date: Sat, 4 Oct 2008 22:43:11 -0600
Subject: [time-nuts] Truetime Time server NTS-100 Downconverter info
 wanted
In-Reply-To: <c9ffea950810041825i78442a21g887d3f2abf9bdcc3@mail.gmail.com>
Message-ID: <C50DA1FF.4890%donw@engineeringinc.com>

Any way to disable it?   The cable run will be like less than 50 feet
--Don





On 10/4/08 7:25 PM, "Scott McGrath" <scmcgrath at gmail.com> wrote:

We have the time vault units - soon to be replaced with 3500's with Rb
Oscillators.

The 'downconverter' is an amplifier used for long cable runs and the
power injection is changed as well.    I would measure what the
NTS-100 is actually putting out without the downconverter our
NTS-300/TimeVault unit puts +12 on the cable it may be much higher for
the downconverter.    There are some TrueTime upconverters on EBAY
right now which should do the job

- Scott




On Sat, Oct 4, 2008 at 12:17 AM, Don E. Wisdom <donw at engineeringinc.com> wrote:
> Hi All,
> I have a NTS-100 GPS model.   I am going to be putting it into use @ my
> employers where I have a T1 & Rooftop access & backup power.   It has the
> lovely "downconverter required" sticker on the back of it.   It does NOT
> like my trimble bullet antenna.   Can someone let me know how I can get this
> working with a Andrews GPS antenna?
> Thanks
> --Don
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.


From donw at engineeringinc.com  Sun Oct  5 00:43:49 2008
From: donw at engineeringinc.com (Don E. Wisdom)
Date: Sat, 4 Oct 2008 22:43:49 -0600
Subject: [time-nuts] Truetime Time server NTS-100 Downconverter
 infowanted
In-Reply-To: <000a01c926a4$b4958680$a101a8c0@officemail>
Message-ID: <C50DA225.4892%donw@engineeringinc.com>

Phil,
Its the GPS unit not the GOES
--Don





On 10/4/08 10:41 PM, "phil" <fortime at bellsouth.net> wrote:

Might it be possible a word of caution is in order?
Was not a "downconverter" used with the old GOES (L-band) Truetime satellite
equipment. That would not be the same as the down converters used on gps.
Just a thought.
Phil


----- Original Message -----
From: "Scott McGrath" <scmcgrath at gmail.com>
To: "Discussion of precise time and frequency measurement"
<time-nuts at febo.com>
Sent: Saturday, October 04, 2008 9:25 PM
Subject: Re: [time-nuts] Truetime Time server NTS-100 Downconverter
infowanted


> We have the time vault units - soon to be replaced with 3500's with Rb
> Oscillators.
>
> The 'downconverter' is an amplifier used for long cable runs and the
> power injection is changed as well.    I would measure what the
> NTS-100 is actually putting out without the downconverter our
> NTS-300/TimeVault unit puts +12 on the cable it may be much higher for
> the downconverter.    There are some TrueTime upconverters on EBAY
> right now which should do the job
>
> - Scott
>
>
>
>
> On Sat, Oct 4, 2008 at 12:17 AM, Don E. Wisdom <donw at engineeringinc.com>
> wrote:
>> Hi All,
>> I have a NTS-100 GPS model.   I am going to be putting it into use @ my
>> employers where I have a T1 & Rooftop access & backup power.   It has the
>> lovely "downconverter required" sticker on the back of it.   It does NOT
>> like my trimble bullet antenna.   Can someone let me know how I can get
>> this
>> working with a Andrews GPS antenna?
>> Thanks
>> --Don
>>
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.


_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.


From fortime at bellsouth.net  Sun Oct  5 00:53:58 2008
From: fortime at bellsouth.net (phil)
Date: Sun, 5 Oct 2008 00:53:58 -0400
Subject: [time-nuts] Truetime Time server NTS-100 Downconverter
	infowanted
References: <C50DA225.4892%donw@engineeringinc.com>
Message-ID: <001501c926a6$612aa0a0$a101a8c0@officemail>

Don,
I understand this gentleman has the NTS-100, it's gps, we have a several of 
them. I have seen Truetime "downconverters" on ebay where they didn't know 
or state what it was for, but in reality it was for the old goes truetime 
receivers.
That's what I meant about being careful what you buy on ebay.
Phil

----- Original Message ----- 
From: "Don E. Wisdom" <donw at engineeringinc.com>
To: "Discussion of precise time and frequency measurement" 
<time-nuts at febo.com>
Sent: Sunday, October 05, 2008 12:43 AM
Subject: Re: [time-nuts] Truetime Time server NTS-100 Downconverter 
infowanted


> Phil,
> Its the GPS unit not the GOES
> --Don
>
>
>
>
>
> On 10/4/08 10:41 PM, "phil" <fortime at bellsouth.net> wrote:
>
> Might it be possible a word of caution is in order?
> Was not a "downconverter" used with the old GOES (L-band) Truetime 
> satellite
> equipment. That would not be the same as the down converters used on gps.
> Just a thought.
> Phil
>
>
> ----- Original Message -----
> From: "Scott McGrath" <scmcgrath at gmail.com>
> To: "Discussion of precise time and frequency measurement"
> <time-nuts at febo.com>
> Sent: Saturday, October 04, 2008 9:25 PM
> Subject: Re: [time-nuts] Truetime Time server NTS-100 Downconverter
> infowanted
>
>
>> We have the time vault units - soon to be replaced with 3500's with Rb
>> Oscillators.
>>
>> The 'downconverter' is an amplifier used for long cable runs and the
>> power injection is changed as well.    I would measure what the
>> NTS-100 is actually putting out without the downconverter our
>> NTS-300/TimeVault unit puts +12 on the cable it may be much higher for
>> the downconverter.    There are some TrueTime upconverters on EBAY
>> right now which should do the job
>>
>> - Scott
>>
>>
>>
>>
>> On Sat, Oct 4, 2008 at 12:17 AM, Don E. Wisdom <donw at engineeringinc.com>
>> wrote:
>>> Hi All,
>>> I have a NTS-100 GPS model.   I am going to be putting it into use @ my
>>> employers where I have a T1 & Rooftop access & backup power.   It has 
>>> the
>>> lovely "downconverter required" sticker on the back of it.   It does NOT
>>> like my trimble bullet antenna.   Can someone let me know how I can get
>>> this
>>> working with a Andrews GPS antenna?
>>> Thanks
>>> --Don
>>>
>>>
>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to
>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there. 



From chris.kuethe at gmail.com  Sun Oct  5 00:56:36 2008
From: chris.kuethe at gmail.com (Chris Kuethe)
Date: Sat, 4 Oct 2008 21:56:36 -0700
Subject: [time-nuts] GPIB Card
In-Reply-To: <48E84520.7070403@bellsouth.net>
References: <48E84520.7070403@bellsouth.net>
Message-ID: <91981b3e0810042156g18385a86k9790f28f06bc13ad@mail.gmail.com>

You mean like this card?
http://www.maxipub.com/electro/photos/dv488.jpg

it could be a Metrabyte DV-488 ... or maybe an MBC-488



On Sat, Oct 4, 2008 at 9:40 PM, Brian Kirby <kirbybq at bellsouth.net> wrote:
> A friend has given me a GPIB card and neither of us know who made it.
>
> First its a standard ISA card and it has a GPIB female plug on the rear.
>    No manufacturer or model number but there is a symbol of a tree on
> the rear (maybe paradise?) and beside is 6323706 rev A 667523.  Made in
> the USA and another number in a corner is 94V-0.
>
> On the chip side of the board it appears to have a NEC controller marked
> big letters D7210C little letters 8308PB.  An assembly number of 6323705
> rev A.  Has another 20 other 74LSxx  glue logic ICs...Card is about 4.5
> inches by 4.25 inches.
>
> Has 5 set of berg pins, one set is A13, A14, next set is 2FX and IE,
> next set is computer IRQs 2 thru 7, then a DRQ1-DAC1-DRQ3-DAC3, then
> last set of DAC2 and DRO2.
>
> It had a 1.44 Mb floppy which suscessfully copied, three files;
> config.sys , DV488PC.sys, and LVDT.C
>
> Config.sys shows:
> BREAK=ON
> BUFFERS=20
> FILES=30
> LASTDRIVE=E
> SHELL=C:\DOS\COMMAND.COM /P /E:256
> DEVICE=C:\DOS\ANSI.SYS
> DEVICE=C:\VIPARSE.SYS
> INSTALL=C:\DOS\FASTOPEN.EXE C:=(50,25)
> DEVICE=C:\DV488PC.SYS
>
> LVDT.C is "C" code for
> for a program written by  a NASA/MSFC employee for the calibration
> of Linear Displacement trunsducers...
>
> Does anybody in the list have an idea of who made the card ?  I'm
> researching to see if it is still usable....
>
>
> Brian - KD4FM
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>



-- 
GDB has a 'break' feature; why doesn't it have 'fix' too?


From hartzell at gmail.com  Sun Oct  5 01:00:51 2008
From: hartzell at gmail.com (Dave hartzell)
Date: Sat, 4 Oct 2008 22:00:51 -0700
Subject: [time-nuts] GPS, NTP, and Cisco routers...
In-Reply-To: <3C932D37-8120-4833-81D8-9AC8C1E73434@rob-vassar.com>
References: <3C932D37-8120-4833-81D8-9AC8C1E73434@rob-vassar.com>
Message-ID: <1c096fd70810042200y29299335n2e75c5c34b574b79@mail.gmail.com>

Looks like Trimble and Cisco got together on a PPS implementation for
the 7200, starting with 12.0T trainwreck:

http://www.cisco.com/en/US/docs/ios/12_1t/12_1t1/feature/guide/dtrimble.html

Since I don't have any 7200s any longer (thank goodness), I checked
and it seems that the 6500s support this as well on the console serial
port:

6509-rtr(config-line)#ntp ?
  pps-discipline  Use PPS pulse to discipline system clock
  refclock        NTP Reference Clock

and

6509-rtr(config-line)#ntp refclock ?
  telecom-solutions  Telecom Solutions GPS
  trimble            Trimble Navigation TSIP Protocol

It looks interesting, and if the code is just looking for a PPS
transition on the CTS or RI, you might be in luck with any external
PPS...

BUT be forewarned, IOS is a cooperative multitasking operating system
(at least prior to the new "modular" stuff), so your accuracy is going
to vary depending on loads, processes, etc.  I wouldn't count on this
being to spectacular...  probably no better than an external NTP
source.

And of course, you can always call the TAC for more assistance!  ;-)

73,
Dave
AF6KD


On Fri, Oct 3, 2008 at 2:39 PM, Robert Vassar <rvassar at rob-vassar.com> wrote:
>
>
>
> I've been fiddling around with an old Cisco router here at the house
> to brush up.  We have an IPv6 project going at work, and our WAN
> provider provides no native transit, so I'm looking at doing some
> tunneling.  Anyhow... I discovered IOS 12.1 and above have native NTP
> capability.  I don't have the exhaustive IOS command reference, and I
> suspect it's a limited NTP implementation. I'm wondering if it's
> possible to tie a GPS unit to a router serial port and gain a stratum
> 0 refclock.
>
>
> Any Cisco guru's on the list?  :-)
>
>
>
> Cheers,
>
> Rob
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>


From phk at phk.freebsd.dk  Sun Oct  5 02:49:10 2008
From: phk at phk.freebsd.dk (Poul-Henning Kamp)
Date: Sun, 05 Oct 2008 06:49:10 +0000
Subject: [time-nuts] GPIB Card
In-Reply-To: Your message of "Sat, 04 Oct 2008 21:56:36 MST."
	<91981b3e0810042156g18385a86k9790f28f06bc13ad@mail.gmail.com> 
Message-ID: <13192.1223189350@critter.freebsd.dk>

In message <91981b3e0810042156g18385a86k9790f28f06bc13ad at mail.gmail.com>, "Chri
s Kuethe" writes:

>You mean like this card?
>http://www.maxipub.com/electro/photos/dv488.jpg
>
>it could be a Metrabyte DV-488 ... or maybe an MBC-488

Most of these cards are 100% compatible with the original IBM GPIB
ISA card, except possibly for the order of the jumpers.

FreeBSD has a driver for them called pciia, and I belive Linux has
one too.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.


From rk at timing-consultants.com  Sun Oct  5 03:51:17 2008
From: rk at timing-consultants.com (Rob Kimberley)
Date: Sun, 5 Oct 2008 08:51:17 +0100
Subject: [time-nuts] Truetime Time server NTS-100 Downconverter
	infowanted
In-Reply-To: <C50DA225.4892%donw@engineeringinc.com>
References: <000a01c926a4$b4958680$a101a8c0@officemail>
	<C50DA225.4892%donw@engineeringinc.com>
Message-ID: <AA6ACF909F2647C2817A18377A740829@Robin>

Don,

Try Googling around to see if you can find the spec for the downconverter.
We recently managed to get an old Odetics 325 working with a Meinberg
antenna/converter unit. Have emailed you the Meinberg manual off list.

Rob Kimberley 

 

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Don E. Wisdom
Sent: 05 October 2008 05:44
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Truetime Time server NTS-100 Downconverter
infowanted

Phil,
Its the GPS unit not the GOES
--Don





On 10/4/08 10:41 PM, "phil" <fortime at bellsouth.net> wrote:

Might it be possible a word of caution is in order?
Was not a "downconverter" used with the old GOES (L-band) Truetime satellite
equipment. That would not be the same as the down converters used on gps.
Just a thought.
Phil


----- Original Message -----
From: "Scott McGrath" <scmcgrath at gmail.com>
To: "Discussion of precise time and frequency measurement"
<time-nuts at febo.com>
Sent: Saturday, October 04, 2008 9:25 PM
Subject: Re: [time-nuts] Truetime Time server NTS-100 Downconverter
infowanted


> We have the time vault units - soon to be replaced with 3500's with Rb 
> Oscillators.
>
> The 'downconverter' is an amplifier used for long cable runs and the
> power injection is changed as well.    I would measure what the
> NTS-100 is actually putting out without the downconverter our 
> NTS-300/TimeVault unit puts +12 on the cable it may be much higher for
> the downconverter.    There are some TrueTime upconverters on EBAY
> right now which should do the job
>
> - Scott
>
>
>
>
> On Sat, Oct 4, 2008 at 12:17 AM, Don E. Wisdom 
> <donw at engineeringinc.com>
> wrote:
>> Hi All,
>> I have a NTS-100 GPS model.   I am going to be putting it into use @ my
>> employers where I have a T1 & Rooftop access & backup power.   It has the
>> lovely "downconverter required" sticker on the back of it.   It does NOT
>> like my trimble bullet antenna.   Can someone let me know how I can get
>> this
>> working with a Andrews GPS antenna?
>> Thanks
>> --Don
>>
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to 
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.


_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



From pfmonet at wanadoo.fr  Sun Oct  5 04:51:18 2008
From: pfmonet at wanadoo.fr (=?iso-8859-1?Q?Pierre-Fran=E7ois_=28f5bqp=5Fpfm=29?=)
Date: Sun, 5 Oct 2008 10:51:18 +0200
Subject: [time-nuts] GPIB Card
References: <13192.1223189350@critter.freebsd.dk>
Message-ID: <00b501c926c7$891c9930$4501a8c0@r44>

Hi,

I believe you're talking about the ISA PCIIA GPIB cards, yes they where 
(still are I guess? ) supported under Linux under the Linux GPIB project.
I was using few of these in the past.
Windows ( at least 98 & XP) doesn't recognise properly these PCIIA cards.

73's
pf, F5BQP


----- Original Message ----- 
From: "Poul-Henning Kamp" <phk at phk.freebsd.dk>
To: "Discussion of precise time and frequency measurement" 
<time-nuts at febo.com>
Sent: Sunday, October 05, 2008 8:49 AM
Subject: Re: [time-nuts] GPIB Card


>
> In message <91981b3e0810042156g18385a86k9790f28f06bc13ad at mail.gmail.com>, 
> "Chri
> s Kuethe" writes:
>
>>You mean like this card?
>>http://www.maxipub.com/electro/photos/dv488.jpg
>>
>>it could be a Metrabyte DV-488 ... or maybe an MBC-488
>
> Most of these cards are 100% compatible with the original IBM GPIB
> ISA card, except possibly for the order of the jumpers.
>
> FreeBSD has a driver for them called pciia, and I belive Linux has
> one too.
>
> -- 
> Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
> phk at FreeBSD.ORG         | TCP/IP since RFC 956
> FreeBSD committer       | BSD since 4.3-tahoe
> Never attribute to malice what can adequately be explained by 
> incompetence.
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>
> __________ Information NOD32 3495 (20081004) __________
>
> Ce message a ete verifie par NOD32 Antivirus System.
> http://www.nod32.com
>
> 




From namichie at gmail.com  Sun Oct  5 07:33:41 2008
From: namichie at gmail.com (Neville Michie)
Date: Sun, 5 Oct 2008 22:33:41 +1100
Subject: [time-nuts] TBolt Monitor
Message-ID: <33928620-888F-48A0-9F52-6427F5F0BEED@gmail.com>

Hi,
I have been having fun with my TBolt, and I am organising a power  
supply to run it off
a 12 volt battery backed up power supply.
I am making my own low headroom regulators, I assume it will perform  
better with precisely
controlled supply voltages.
What I need next is a monitor to show the current UTC time and  
perhaps a monitor function or two.
That will be used to set  a PPS counting clock which is for setting  
my clocks while I use the 10 MHz to drive
a time stamping logger that records the timing of the escapements of  
the clocks (pendulum type) being analysed.
I saw the monitor Didier was proposing, but my skills with micros are  
quite limited
so are there any suggestions for a low power, simple monitor that I  
can recover UTC with to set my PPS counting
clock? The clock will be either or both of a seconds indicating slave  
dial and a 6 digit large LED display.
cheers,
Neville Michie


From w3kl at w3kl.com  Sun Oct  5 08:48:35 2008
From: w3kl at w3kl.com (Jeffrey Okamitsu)
Date: Sun, 5 Oct 2008 05:48:35 -0700 (PDT)
Subject: [time-nuts] HP 5061B - Beam Current
Message-ID: <760585.20748.qm@web35408.mail.mud.yahoo.com>

I've spent a good deal of time this weekend working with the 5061B I recently acquired.
?
The unit appears to be making stable 10 MHz.? I've compared it the the Rubidium source I have and the two compare as expected.
?
There are two problems:
?
1) Beam current is low - even after going carefully through the alignment procedure outline in the service manual, the best I can get (Loop Open, Mod Off) is a bit over 10 nA.
2) The "Continuous Operation" LED will not come on after pressing Logic Reset.? I used the trouble shooting guide to diagnose the LED and it's pointing to the circuit on the A14 board.? This is as far as I have gotten so far. Note that the trouble shooting guide is suggesting that it might not be a problem with beam current, but an electronics problem (the LED driver).
?
Anyone have any insight?
?
Thanks for reading.
?
Jeff

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

From rvassar at rob-vassar.com  Sun Oct  5 09:22:02 2008
From: rvassar at rob-vassar.com (Robert Vassar)
Date: Sun, 5 Oct 2008 08:22:02 -0500
Subject: [time-nuts] GPS, NTP, and Cisco routers...
In-Reply-To: <1c096fd70810042200y29299335n2e75c5c34b574b79@mail.gmail.com>
References: <3C932D37-8120-4833-81D8-9AC8C1E73434@rob-vassar.com>
	<1c096fd70810042200y29299335n2e75c5c34b574b79@mail.gmail.com>
Message-ID: <E03D6F5A-92C6-4BC6-8ABB-77783804CA24@rob-vassar.com>



It looks like the feature set varies significantly with the router  
model, and by IOS feature set.  The router I have here is an eBay  
special, an old 2514.  It's probably 10 years old, though I think  
Cisco continued to make them until about 2003.  It's only configured  
with 8mb flash, so it can only run the stripped down IP subset.  
(which lacks the IPv6 stuff I need too...)  Every few years I dabble  
with ploughing thru the CC** tests, but I'm a QA engineer, so it  
never becomes a priority.


It's running c2500-i-l.121-27b.bin, and my ntp menu looks quite  
different:

Router2#config t
Enter configuration commands, one per line.  End with CNTL/Z.
Router2(config)#ntp ?
   access-group        Control NTP access
   authenticate        Authenticate time sources
   authentication-key  Authentication key for trusted time sources
   broadcastdelay      Estimated round-trip delay
   clock-period        Length of hardware clock tick
   master              Act as NTP master clock
   max-associations    Set maximum number of associations
   peer                Configure NTP peer
   server              Configure NTP server
   source              Configure interface for source address
   trusted-key         Key numbers for trusted time sources

Router2(config)#^Z

No "refclock" option.  If I had a 16mb flash card, I could run the  
"Enterprise" image, which might have different features.  But a 16mb  
flash card and FPM SIMM cost more than this router is worth.  It  
appears to be NTP v3 as well, though all my Solaris boxes run v3 due  
to some issues with NTP 4.x and the kernel clock code. (It's being  
fixed...)


I'll have to look at one of the newer models I have in the lab at  
work.  I've also been thinking of buying an 851w for my DSL line here  
at the house.  I've outgrown my WRT54G, even running Tomato, perhaps  
I'll be pleasantly surprised.  I hadn't even looked at Cisco stuff  
since 2002 or so, certainly pre-12.1 anyway.  I was just kind of  
surprised to come across an NTP server at all, and I was curious what  
its "Time-Nuts hackability" rating was.  :-)


Thanks and 73,

Rob
KC6OOM/5




On Oct 5, 2008, at 12:00 AM, Dave hartzell wrote:

> Looks like Trimble and Cisco got together on a PPS implementation for
> the 7200, starting with 12.0T trainwreck:
>
> http://www.cisco.com/en/US/docs/ios/12_1t/12_1t1/feature/guide/ 
> dtrimble.html
>
> Since I don't have any 7200s any longer (thank goodness), I checked
> and it seems that the 6500s support this as well on the console serial
> port:
>
> 6509-rtr(config-line)#ntp ?
>   pps-discipline  Use PPS pulse to discipline system clock
>   refclock        NTP Reference Clock
>
> and
>
> 6509-rtr(config-line)#ntp refclock ?
>   telecom-solutions  Telecom Solutions GPS
>   trimble            Trimble Navigation TSIP Protocol
>
> It looks interesting, and if the code is just looking for a PPS
> transition on the CTS or RI, you might be in luck with any external
> PPS...
>
> BUT be forewarned, IOS is a cooperative multitasking operating system
> (at least prior to the new "modular" stuff), so your accuracy is going
> to vary depending on loads, processes, etc.  I wouldn't count on this
> being to spectacular...  probably no better than an external NTP
> source.
>
> And of course, you can always call the TAC for more assistance!  ;-)
>
> 73,
> Dave
> AF6KD
>
>
> On Fri, Oct 3, 2008 at 2:39 PM, Robert Vassar <rvassar at rob- 
> vassar.com> wrote:
>>
>>
>>
>> I've been fiddling around with an old Cisco router here at the house
>> to brush up.  We have an IPv6 project going at work, and our WAN
>> provider provides no native transit, so I'm looking at doing some
>> tunneling.  Anyhow... I discovered IOS 12.1 and above have native NTP
>> capability.  I don't have the exhaustive IOS command reference, and I
>> suspect it's a limited NTP implementation. I'm wondering if it's
>> possible to tie a GPS unit to a router serial port and gain a stratum
>> 0 refclock.
>>
>>
>> Any Cisco guru's on the list?  :-)
>>
>>
>>
>> Cheers,
>>
>> Rob
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/ 
>> listinfo/time-nuts
>> and follow the instructions there.
>>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ 
> time-nuts
> and follow the instructions there.



From didier at cox.net  Sun Oct  5 12:08:46 2008
From: didier at cox.net (Didier Juges)
Date: Sun, 5 Oct 2008 11:08:46 -0500
Subject: [time-nuts] TBolt Monitor
In-Reply-To: <33928620-888F-48A0-9F52-6427F5F0BEED@gmail.com>
References: <33928620-888F-48A0-9F52-6427F5F0BEED@gmail.com>
Message-ID: <5A4EFAE4A47A4D428BED3350ECF22BED@didierhp>

Tell me what kind of signal you need to drive your clock, and I may be able
to get what you need from the processor.

Didier KO4BB 

> -----Original Message-----
> From: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Neville Michie
> Sent: Sunday, October 05, 2008 6:34 AM
> To: Discussion of precise time and frequency measurement
> Subject: [time-nuts] TBolt Monitor
> 
> Hi,
> I have been having fun with my TBolt, and I am organising a 
> power supply to run it off a 12 volt battery backed up power supply.
> I am making my own low headroom regulators, I assume it will 
> perform better with precisely controlled supply voltages.
> What I need next is a monitor to show the current UTC time 
> and perhaps a monitor function or two.
> That will be used to set  a PPS counting clock which is for 
> setting my clocks while I use the 10 MHz to drive a time 
> stamping logger that records the timing of the escapements of 
> the clocks (pendulum type) being analysed.
> I saw the monitor Didier was proposing, but my skills with 
> micros are quite limited so are there any suggestions for a 
> low power, simple monitor that I can recover UTC with to set 
> my PPS counting clock? The clock will be either or both of a 
> seconds indicating slave dial and a 6 digit large LED display.
> cheers,
> Neville Michie
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com To unsubscribe, 
> go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.



From didier at cox.net  Sun Oct  5 12:10:27 2008
From: didier at cox.net (Didier Juges)
Date: Sun, 5 Oct 2008 11:10:27 -0500
Subject: [time-nuts] GPIB Card
In-Reply-To: <48E84520.7070403@bellsouth.net>
References: <48E84520.7070403@bellsouth.net>
Message-ID: <50012835732C47AA918C32082024101B@didierhp>

The NEC 7210 was the industry standard GPIB chip for over 20 years, I still
have a few here. If you want the spec and can't find it, I probably have it
here somewhere.

Didier 

> -----Original Message-----
> From: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Brian Kirby
> Sent: Saturday, October 04, 2008 11:40 PM
> To: Discussion of precise time and frequency measurement
> Subject: [time-nuts] GPIB Card
> 
> A friend has given me a GPIB card and neither of us know who made it.
> 
> First its a standard ISA card and it has a GPIB female plug 
> on the rear. 
>     No manufacturer or model number but there is a symbol of 
> a tree on the rear (maybe paradise?) and beside is 6323706 
> rev A 667523.  Made in the USA and another number in a corner 
> is 94V-0.
> 
> On the chip side of the board it appears to have a NEC 
> controller marked big letters D7210C little letters 8308PB.  
> An assembly number of 6323705 rev A.  Has another 20 other 
> 74LSxx  glue logic ICs...Card is about 4.5 inches by 4.25 inches.
> 
> Has 5 set of berg pins, one set is A13, A14, next set is 2FX 
> and IE, next set is computer IRQs 2 thru 7, then a 
> DRQ1-DAC1-DRQ3-DAC3, then last set of DAC2 and DRO2.
> 
> It had a 1.44 Mb floppy which suscessfully copied, three 
> files; config.sys , DV488PC.sys, and LVDT.C
> 
> Config.sys shows:
> BREAK=ON
> BUFFERS=20
> FILES=30
> LASTDRIVE=E
> SHELL=C:\DOS\COMMAND.COM /P /E:256
> DEVICE=C:\DOS\ANSI.SYS
> DEVICE=C:\VIPARSE.SYS
> INSTALL=C:\DOS\FASTOPEN.EXE C:=(50,25)
> DEVICE=C:\DV488PC.SYS
> 
> LVDT.C is "C" code for
> for a program written by  a NASA/MSFC employee for the 
> calibration of Linear Displacement trunsducers...
> 
> Does anybody in the list have an idea of who made the card ?  
> I'm researching to see if it is still usable....
> 
> 
> Brian - KD4FM
> 
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.



From pfmonet at wanadoo.fr  Sun Oct  5 12:31:57 2008
From: pfmonet at wanadoo.fr (=?iso-8859-1?Q?Pierre-Fran=E7ois_=28f5bqp=5Fpfm=29?=)
Date: Sun, 5 Oct 2008 18:31:57 +0200
Subject: [time-nuts] GPIB Card
References: <48E84520.7070403@bellsouth.net>
	<50012835732C47AA918C32082024101B@didierhp>
Message-ID: <359d01c92707$e3411f40$4501a8c0@r44>

Hi,

If it looks like this one:
http://www.measurementcomputing.com/pdfs/isa-gpib-pc2a.pdf
then it could be a legacy ISA PC2IIA from NI or a compatible one.

pf



----- Original Message ----- 
From: "Didier Juges" <didier at cox.net>
To: "'Discussion of precise time and frequency measurement'" 
<time-nuts at febo.com>
Sent: Sunday, October 05, 2008 6:10 PM
Subject: Re: [time-nuts] GPIB Card


>
> The NEC 7210 was the industry standard GPIB chip for over 20 years, I 
> still
> have a few here. If you want the spec and can't find it, I probably have 
> it
> here somewhere.
>
> Didier
>
>> -----Original Message-----
>> From: time-nuts-bounces at febo.com
>> [mailto:time-nuts-bounces at febo.com] On Behalf Of Brian Kirby
>> Sent: Saturday, October 04, 2008 11:40 PM
>> To: Discussion of precise time and frequency measurement
>> Subject: [time-nuts] GPIB Card
>>
>> A friend has given me a GPIB card and neither of us know who made it.
>>
>> First its a standard ISA card and it has a GPIB female plug
>> on the rear.
>>     No manufacturer or model number but there is a symbol of
>> a tree on the rear (maybe paradise?) and beside is 6323706
>> rev A 667523.  Made in the USA and another number in a corner
>> is 94V-0.
>>
>> On the chip side of the board it appears to have a NEC
>> controller marked big letters D7210C little letters 8308PB.
>> An assembly number of 6323705 rev A.  Has another 20 other
>> 74LSxx  glue logic ICs...Card is about 4.5 inches by 4.25 inches.
>>
>> Has 5 set of berg pins, one set is A13, A14, next set is 2FX
>> and IE, next set is computer IRQs 2 thru 7, then a
>> DRQ1-DAC1-DRQ3-DAC3, then last set of DAC2 and DRO2.
>>
>> It had a 1.44 Mb floppy which suscessfully copied, three
>> files; config.sys , DV488PC.sys, and LVDT.C
>>
>> Config.sys shows:
>> BREAK=ON
>> BUFFERS=20
>> FILES=30
>> LASTDRIVE=E
>> SHELL=C:\DOS\COMMAND.COM /P /E:256
>> DEVICE=C:\DOS\ANSI.SYS
>> DEVICE=C:\VIPARSE.SYS
>> INSTALL=C:\DOS\FASTOPEN.EXE C:=(50,25)
>> DEVICE=C:\DV488PC.SYS
>>
>> LVDT.C is "C" code for
>> for a program written by  a NASA/MSFC employee for the
>> calibration of Linear Displacement trunsducers...
>>
>> Does anybody in the list have an idea of who made the card ?
>> I'm researching to see if it is still usable....
>>
>>
>> Brian - KD4FM
>>
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>
> __________ Information NOD32 3495 (20081004) __________
>
> Ce message a ete verifie par NOD32 Antivirus System.
> http://www.nod32.com
>
> 




From scmcgrath at gmail.com  Sun Oct  5 12:43:31 2008
From: scmcgrath at gmail.com (Scott McGrath)
Date: Sun, 5 Oct 2008 12:43:31 -0400
Subject: [time-nuts] GPS, NTP, and Cisco routers...
In-Reply-To: <1c096fd70810042200y29299335n2e75c5c34b574b79@mail.gmail.com>
References: <3C932D37-8120-4833-81D8-9AC8C1E73434@rob-vassar.com>
	<1c096fd70810042200y29299335n2e75c5c34b574b79@mail.gmail.com>
Message-ID: <c9ffea950810050943x145e719m25daa3c6a3ca361f@mail.gmail.com>

Actually you might get pretty good results if you have a 6509 as any
activity on the serial port triggers a CPU interrupt which is why on a
overloaded 6509 the first thing to try is "no logging console" to get
the cpu down from 100% - usually in the context of DDoS and the
control plane is slammed as the EOBC is only a 1 megabit channel even
on the 3BXL's.    This is one of the advantages of the annual trek out
to Bldg 14 in San Jose - one gets to meet the guys who developed the
code for the routers.

This has more than passing interest for me as one could take a NovaTel
GPSCard which has a 1PPS output and runs on a single 12-36V supply and
has a dedicated 1PPS output at serial levels and install one at each
router location.    Still have not disassembled the 2501 and 2611 to
see which cheapo TCXO Cisco has installed.


What do you have available at your shop - we are running SUP720-3BXL's
running 12.2 SXF

On Sun, Oct 5, 2008 at 1:00 AM, Dave hartzell <hartzell at gmail.com> wrote:
> Looks like Trimble and Cisco got together on a PPS implementation for
> the 7200, starting with 12.0T trainwreck:
>
> http://www.cisco.com/en/US/docs/ios/12_1t/12_1t1/feature/guide/dtrimble.html
>
> Since I don't have any 7200s any longer (thank goodness), I checked
> and it seems that the 6500s support this as well on the console serial
> port:
>
> 6509-rtr(config-line)#ntp ?
>  pps-discipline  Use PPS pulse to discipline system clock
>  refclock        NTP Reference Clock
>
> and
>
> 6509-rtr(config-line)#ntp refclock ?
>  telecom-solutions  Telecom Solutions GPS
>  trimble            Trimble Navigation TSIP Protocol
>
> It looks interesting, and if the code is just looking for a PPS
> transition on the CTS or RI, you might be in luck with any external
> PPS...
>
> BUT be forewarned, IOS is a cooperative multitasking operating system
> (at least prior to the new "modular" stuff), so your accuracy is going
> to vary depending on loads, processes, etc.  I wouldn't count on this
> being to spectacular...  probably no better than an external NTP
> source.
>
> And of course, you can always call the TAC for more assistance!  ;-)
>
> 73,
> Dave
> AF6KD
>
>
> On Fri, Oct 3, 2008 at 2:39 PM, Robert Vassar <rvassar at rob-vassar.com> wrote:
>>
>>
>>
>> I've been fiddling around with an old Cisco router here at the house
>> to brush up.  We have an IPv6 project going at work, and our WAN
>> provider provides no native transit, so I'm looking at doing some
>> tunneling.  Anyhow... I discovered IOS 12.1 and above have native NTP
>> capability.  I don't have the exhaustive IOS command reference, and I
>> suspect it's a limited NTP implementation. I'm wondering if it's
>> possible to tie a GPS unit to a router serial port and gain a stratum
>> 0 refclock.
>>
>>
>> Any Cisco guru's on the list?  :-)
>>
>>
>>
>> Cheers,
>>
>> Rob
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>


From scmcgrath at gmail.com  Sun Oct  5 12:45:59 2008
From: scmcgrath at gmail.com (Scott McGrath)
Date: Sun, 5 Oct 2008 12:45:59 -0400
Subject: [time-nuts] HP 5061B - Beam Current
In-Reply-To: <760585.20748.qm@web35408.mail.mud.yahoo.com>
References: <760585.20748.qm@web35408.mail.mud.yahoo.com>
Message-ID: <c9ffea950810050945u880d185g84b6d70ab6773179@mail.gmail.com>

Did you try the LF injection test?


On Sun, Oct 5, 2008 at 8:48 AM, Jeffrey Okamitsu <w3kl at w3kl.com> wrote:
> I've spent a good deal of time this weekend working with the 5061B I recently acquired.
>
> The unit appears to be making stable 10 MHz.  I've compared it the the Rubidium source I have and the two compare as expected.
>
> There are two problems:
>
> 1) Beam current is low - even after going carefully through the alignment procedure outline in the service manual, the best I can get (Loop Open, Mod Off) is a bit over 10 nA.
> 2) The "Continuous Operation" LED will not come on after pressing Logic Reset.  I used the trouble shooting guide to diagnose the LED and it's pointing to the circuit on the A14 board.  This is as far as I have gotten so far. Note that the trouble shooting guide is suggesting that it might not be a problem with beam current, but an electronics problem (the LED driver).
>
> Anyone have any insight?
>
> Thanks for reading.
>
> Jeff
>
> Jeffrey K. Okamitsu, PhD, MBA
> +1-609-638-5402
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>


From cdelect at juno.com  Sun Oct  5 12:46:03 2008
From: cdelect at juno.com (corby d dawson)
Date: Sun, 5 Oct 2008 09:46:03 -0700
Subject: [time-nuts] 5061B info.
Message-ID: <20081005.094604.-522037.0.cdelect@juno.com>

Jeff,

What is the 2nd harmonic meter reading?

If it is too low you will not be able to get the operate light on.

While watching the 2nd harmonic reading adjust the front panel beam I pot
for a reading of 35 to 45.

If pot is at max adjust the loop gain thru the front panel hole for the
35-45 reading, if it's at max and the top switch on the A7 is in low
gain, switch it to high and try the loop gin adjust again.

If the 2nd harmonic is OK but still no operate light, check the operate
lamp, if OK then remove the bottom cover and find the two wires pushed
onto the connections on the synthesizer board. Leave the red one
connected but remove the other.

Now push the logic reset and see if the operate light comes on. 

If so then the sythesizer is not properly locked and is your problem.

Good Luck,

Corby Dawson
____________________________________________________________
All is not lost! Click now for professional data recovery.
http://thirdpartyoffers.juno.com/TGL2141/fc/Ioyw6i3ni7fYBkXybnqb9nxcS0QRCgWT2m1rhqVkpQ2Y6lLNgG5X7j/


From scmcgrath at gmail.com  Sun Oct  5 12:50:54 2008
From: scmcgrath at gmail.com (Scott McGrath)
Date: Sun, 5 Oct 2008 12:50:54 -0400
Subject: [time-nuts] Truetime Time server NTS-100 Downconverter
	infowanted
In-Reply-To: <000a01c926a4$b4958680$a101a8c0@officemail>
References: <C50C4A6C.47C8%donw@engineeringinc.com>
	<c9ffea950810041825i78442a21g887d3f2abf9bdcc3@mail.gmail.com>
	<000a01c926a4$b4958680$a101a8c0@officemail>
Message-ID: <c9ffea950810050950q5052a3c0v154406698249b2fa@mail.gmail.com>

Second on the - be careful on what you buy

BUT Symmetricom does sell the 'downconverter' for long cable runs -
It's also cheap (relatively) as I recall on the order of $200-300 as
we needed one for one of our installations which is machine room in
basement antenna at top of 15 story building.

The manual is available for free download from Symmetricom - I 'll
look in my hardcopy manual to see if there is a jumper which needs to
be reset the NTS-100-300 all shared the same GPS engine but they all
had different software features on the ethernet side.

On Sun, Oct 5, 2008 at 12:41 AM, phil <fortime at bellsouth.net> wrote:
> Might it be possible a word of caution is in order?
> Was not a "downconverter" used with the old GOES (L-band) Truetime satellite
> equipment. That would not be the same as the down converters used on gps.
> Just a thought.
> Phil
>
>
> ----- Original Message -----
> From: "Scott McGrath" <scmcgrath at gmail.com>
> To: "Discussion of precise time and frequency measurement"
> <time-nuts at febo.com>
> Sent: Saturday, October 04, 2008 9:25 PM
> Subject: Re: [time-nuts] Truetime Time server NTS-100 Downconverter
> infowanted
>
>
>> We have the time vault units - soon to be replaced with 3500's with Rb
>> Oscillators.
>>
>> The 'downconverter' is an amplifier used for long cable runs and the
>> power injection is changed as well.    I would measure what the
>> NTS-100 is actually putting out without the downconverter our
>> NTS-300/TimeVault unit puts +12 on the cable it may be much higher for
>> the downconverter.    There are some TrueTime upconverters on EBAY
>> right now which should do the job
>>
>> - Scott
>>
>>
>>
>>
>> On Sat, Oct 4, 2008 at 12:17 AM, Don E. Wisdom <donw at engineeringinc.com>
>> wrote:
>>> Hi All,
>>> I have a NTS-100 GPS model.   I am going to be putting it into use @ my
>>> employers where I have a T1 & Rooftop access & backup power.   It has the
>>> lovely "downconverter required" sticker on the back of it.   It does NOT
>>> like my trimble bullet antenna.   Can someone let me know how I can get
>>> this
>>> working with a Andrews GPS antenna?
>>> Thanks
>>> --Don
>>>
>>>
>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to
>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>


From smace at intt.net  Sun Oct  5 13:32:51 2008
From: smace at intt.net (Scott Mace)
Date: Sun, 05 Oct 2008 12:32:51 -0500
Subject: [time-nuts] GPS, NTP, and Cisco routers...
In-Reply-To: <c9ffea950810050943x145e719m25daa3c6a3ca361f@mail.gmail.com>
References: <3C932D37-8120-4833-81D8-9AC8C1E73434@rob-vassar.com>	<1c096fd70810042200y29299335n2e75c5c34b574b79@mail.gmail.com>
	<c9ffea950810050943x145e719m25daa3c6a3ca361f@mail.gmail.com>
Message-ID: <48E8FA43.2070701@intt.net>

This runs on the aux port, and the sup720 doesn't have an aux port...
There are always obscure features that slip into the production releases
that aren't tested and they just forget to exclude them during builds.
TAC will probably have no clue about this...
You could try the cisco-nsp mailling list for support, but beware, it's
frequented by cisco developers that will just as soon open a bug-id to
drop 'feature' from the production release if it was never supposed to
be there in the first place.

I wonder if this was originally used as an alternative method to time
the MIX midplane in the VXR chassis and the NTP feature was side
benefit?  Most telecom gear that needs synchronization will take a
BITS input or some other frequency reference.  I've used that extensively
with SONET gear and the good old Datum OT-21.  I never used the
7200 MIX, so I'm not sure if it could take an external reference or
just recover clock from a DS1 port.

Seems like a good use for an AUX port if you don't need a modem or
reverse telnet!

	Scott

Scott McGrath wrote:
> Actually you might get pretty good results if you have a 6509 as any
> activity on the serial port triggers a CPU interrupt which is why on a
> overloaded 6509 the first thing to try is "no logging console" to get
> the cpu down from 100% - usually in the context of DDoS and the
> control plane is slammed as the EOBC is only a 1 megabit channel even
> on the 3BXL's.    This is one of the advantages of the annual trek out
> to Bldg 14 in San Jose - one gets to meet the guys who developed the
> code for the routers.
> 
> This has more than passing interest for me as one could take a NovaTel
> GPSCard which has a 1PPS output and runs on a single 12-36V supply and
> has a dedicated 1PPS output at serial levels and install one at each
> router location.    Still have not disassembled the 2501 and 2611 to
> see which cheapo TCXO Cisco has installed.
> 
> 
> What do you have available at your shop - we are running SUP720-3BXL's
> running 12.2 SXF
> 
> On Sun, Oct 5, 2008 at 1:00 AM, Dave hartzell <hartzell at gmail.com> wrote:
>> Looks like Trimble and Cisco got together on a PPS implementation for
>> the 7200, starting with 12.0T trainwreck:
>>
>> http://www.cisco.com/en/US/docs/ios/12_1t/12_1t1/feature/guide/dtrimble.html
>>
>> Since I don't have any 7200s any longer (thank goodness), I checked
>> and it seems that the 6500s support this as well on the console serial
>> port:
>>
>> 6509-rtr(config-line)#ntp ?
>>  pps-discipline  Use PPS pulse to discipline system clock
>>  refclock        NTP Reference Clock
>>
>> and
>>
>> 6509-rtr(config-line)#ntp refclock ?
>>  telecom-solutions  Telecom Solutions GPS
>>  trimble            Trimble Navigation TSIP Protocol
>>
>> It looks interesting, and if the code is just looking for a PPS
>> transition on the CTS or RI, you might be in luck with any external
>> PPS...
>>
>> BUT be forewarned, IOS is a cooperative multitasking operating system
>> (at least prior to the new "modular" stuff), so your accuracy is going
>> to vary depending on loads, processes, etc.  I wouldn't count on this
>> being to spectacular...  probably no better than an external NTP
>> source.
>>
>> And of course, you can always call the TAC for more assistance!  ;-)
>>
>> 73,
>> Dave
>> AF6KD
>>
>>
>> On Fri, Oct 3, 2008 at 2:39 PM, Robert Vassar <rvassar at rob-vassar.com> wrote:
>>>
>>>
>>> I've been fiddling around with an old Cisco router here at the house
>>> to brush up.  We have an IPv6 project going at work, and our WAN
>>> provider provides no native transit, so I'm looking at doing some
>>> tunneling.  Anyhow... I discovered IOS 12.1 and above have native NTP
>>> capability.  I don't have the exhaustive IOS command reference, and I
>>> suspect it's a limited NTP implementation. I'm wondering if it's
>>> possible to tie a GPS unit to a router serial port and gain a stratum
>>> 0 refclock.
>>>
>>>
>>> Any Cisco guru's on the list?  :-)
>>>
>>>
>>>
>>> Cheers,
>>>
>>> Rob
>>>
>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 
> 


From Murray.Greenman at rakon.com  Sun Oct  5 13:37:47 2008
From: Murray.Greenman at rakon.com (Murray Greenman)
Date: Mon, 6 Oct 2008 06:37:47 +1300
Subject: [time-nuts] time-nuts Digest, Vol 51, Issue 8
In-Reply-To: <mailman.219.1223001504.2205.time-nuts@febo.com>
References: <mailman.219.1223001504.2205.time-nuts@febo.com>
Message-ID: <BE50C3A72EBA61449C804B2C8B4AE381D05948@NEPTUNE.rakon.net>

Steve,

The suggestion of using the mains frequency as a reference is not
practical. There will be no certainty, even after counting for a week
that the mains frequency will give you a reliable reference. You said it
yourself - "the instantaneous frequency of the mains is not always spot
on".

The mains frequency specification is probably set down in a regulation
somewhere, and it probably accounts only for a mean number of cycles per
day, and so the counting period required to lock a reference would be
too long. Essentially it is a reference with immense low frequency phase
noise. Heaven knows, it's a challenge locking 10MHz to 1Hz, so locking
to 1/86400Hz would be very difficult.

An early mains frequency controller for power stations used a pair of
synchronous clock motors (one on the mains, one driven by a
crystal-controlled source), driving a differential gearbox which drove a
pointer calibrated in 'seconds fast/slow', so potentially you could do
the electronic equivalent, but I doubt that it would be capable of
better performance than the OCXO on its own.

If you want a cheap and cheerful 50Hz reference in NZ, use the frame
frequency of TVNZ's TV1 or TV2 transmissions. They have a Trimble
Thunderbolt GPSDO driving the sync generator. Just pull the sync out of
an old video recorder. It's all been done before. Electronics Australia
about 1976!

73,
Murray ZL1BPU



From weyster at cfl.rr.com  Sun Oct  5 15:17:13 2008
From: weyster at cfl.rr.com (Hank)
Date: Sun, 5 Oct 2008 15:17:13 -0400
Subject: [time-nuts]  THUNBERBOLT PACKET 0X8F-AB
Message-ID: <DF5A669AE161421587825BE058308712@whe7d219f70f9a>

Ed
Per your message : That would be the 'byte stuffing' inherent in TSIP packet structure.

Packet 0X8F-AB is specified as being 17 bytes including the subcode ( 8F)
Do you mean that you cant depend on that packet  always being 17 bytes ?
I'm getting 18 bytes only when the time has 16 seconds in it. ( the second byte is duplicated )

If you cant depend on having a constant number of bytes ( as defined in the spec ) , how do you then decode it ?

Thanks
Hank



From weyster at cfl.rr.com  Sun Oct  5 15:26:16 2008
From: weyster at cfl.rr.com (Hank)
Date: Sun, 5 Oct 2008 15:26:16 -0400
Subject: [time-nuts] THUNBERBOLT PACKET 0X8F-AB
Message-ID: <0DFB62B49F744B9192C5A5ADA474ADE0@whe7d219f70f9a>

Ed,

Got it....Found the spec !  Thanks for the hint !

Hank



"The bytes in the data string can have any value. To prevent confusion with the frame

sequences <DLE> <ID> and <DLE> <ETX>, every <DLE> byte in the data string is

preceded by an extra <DLE> byte ('stuffing'). These extra <DLE> bytes must be added

('stuffed') before sending a packet and removed after receiving the packet."

  ----- Original Message ----- 
  From: Hank 
  To: time-nuts at febo.com 
  Sent: Sunday, October 05, 2008 3:17 PM
  Subject: [time-nuts] THUNBERBOLT PACKET 0X8F-AB


  Ed
  Per your message : That would be the 'byte stuffing' inherent in TSIP packet structure.

  Packet 0X8F-AB is specified as being 17 bytes including the subcode ( 8F)
  Do you mean that you cant depend on that packet  always being 17 bytes ?
  I'm getting 18 bytes only when the time has 16 seconds in it. ( the second byte is duplicated )

  If you cant depend on having a constant number of bytes ( as defined in the spec ) , how do you then decode it ?

  Thanks
  Hank



From hmurray at megapathdsl.net  Sun Oct  5 15:32:27 2008
From: hmurray at megapathdsl.net (Hal Murray)
Date: Sun, 05 Oct 2008 12:32:27 -0700
Subject: [time-nuts] THUNBERBOLT PACKET 0X8F-AB
In-Reply-To: Message from "Hank" <weyster@cfl.rr.com> of "Sun,
	05 Oct 2008 15:17:13 EDT."
	<DF5A669AE161421587825BE058308712@whe7d219f70f9a> 
Message-ID: <20081005193228.F1057BCD5@ip-64-139-1-69.sjc.megapath.net>


> If you cant depend on having a constant number of bytes ( as defined
> in the spec ) , how do you then decode it ? 

You have to do the de-stuffing before you check the length and decode the 
packet.

It will be obvious after you see it.  If the Trimble manual isn't good 
enough, google for byte-stuffing.

You will have similar troubles when other bytes have the magic value.  
Minutes and hours seem like good candidates.

-- 
These are my opinions, not necessarily my employer's.  I hate spam.





From hmurray at megapathdsl.net  Sun Oct  5 17:08:08 2008
From: hmurray at megapathdsl.net (Hal Murray)
Date: Sun, 05 Oct 2008 14:08:08 -0700
Subject: [time-nuts] Time from power lines
In-Reply-To: Message from "Murray Greenman" <Murray.Greenman@rakon.com> 
	of "Mon, 06 Oct 2008 06:37:47 +1300."
	<BE50C3A72EBA61449C804B2C8B4AE381D05948@NEPTUNE.rakon.net> 
Message-ID: <20081005210809.D100ABCD5@ip-64-139-1-69.sjc.megapath.net>

(I forgot what the subject of this thread was, but it's not time-nuts Digest)


> The suggestion of using the mains frequency as a reference is not
> practical. There will be no certainty, even after counting for a week
> that the mains frequency will give you a reliable reference. You said
> it yourself - "the instantaneous frequency of the mains is not always
> spot on". 

That doesn't sound quite right.  I think there are several parameters, and 
some combinations might be interesting.

Here are the ones I can think of:
  How stable is the clock you are trying to measure?
  How accurately are you trying to measure it?
  How long are you willing to wait?


> If you want a cheap and cheerful 50Hz reference in NZ, use the frame
> frequency of TVNZ's TV1 or TV2 transmissions.

Is that exactly 50 Hz?  US TV is slightly off 60 Hz.

  

-- 
These are my opinions, not necessarily my employer's.  I hate spam.





From namichie at gmail.com  Sun Oct  5 18:19:44 2008
From: namichie at gmail.com (Neville Michie)
Date: Mon, 6 Oct 2008 09:19:44 +1100
Subject: [time-nuts] TBolt Monitor
In-Reply-To: <5A4EFAE4A47A4D428BED3350ECF22BED@didierhp>
References: <33928620-888F-48A0-9F52-6427F5F0BEED@gmail.com>
	<5A4EFAE4A47A4D428BED3350ECF22BED@didierhp>
Message-ID: <768835EB-4675-4E19-8971-7C2C9098ADA6@gmail.com>

The clock displays are of two types. The analogue dials use alternate  
negative and positive pulses
and are easily generated with a 0.5 Hz square wave signal. These  
dials are either slaves from master clock systems or
a cheap quartz clock dial with leads to the driver coil. A totem pole  
driver drives a capacitor that delivers
the appropriate impulse to the dial motor. This can be conveniently  
generated by a PPS signal straight from the TBolt.
The other display is a series of decimal counters decoded to produce  
a 60 X 60 X 24 display. This also can be driven
from the PPS from the TBolt.
The problem is setting either clock to UTC (or local time). A pulse  
counting system can always either miss a pulse or
respond to a glitch to get the count out of sequence. A two phase  
clocking system can reduce this problem but there
still remains the problem of start up and confidence checking.
The TBolt could just drive the displays directly, but loss of signal  
or power drop-out requires a procedure to resynchronise
the indicators and it would be better to have the displays autonomous  
in the absence of the GPS timing. I am thinking of a TCXO
to carry over the timing for long power failures, that can be done  
with a milliwatt.
Leap seconds are another consideration, so what I think might be most  
useful is a BCD seconds output from the monitor.
This could be jammed into the pulse counter to correct it and could  
be decoded to give one minute pips like WWV to set
an analogue dial.
Just having a low power monitor indicating UTC is 99% of the required  
solution.
All of this is the alternative to running a PC to support the TBolt  
and so avoid the power demand and inconvenient size of the PC.
So what I want is a tiny black box to connect to the TBolt that would  
indicate UTC. Constructing a micro project is no problem,
but the program development and installation is a sticking point.
cheers, Neville Michie

On 06/10/2008, at 3:08 AM, Didier Juges wrote:

> Tell me what kind of signal you need to drive your clock, and I may  
> be able
> to get what you need from the processor.
>
> Didier KO4BB
>
>> -----Original Message-----
>> From: time-nuts-bounces at febo.com
>> [mailto:time-nuts-bounces at febo.com] On Behalf Of Neville Michie
>> Sent: Sunday, October 05, 2008 6:34 AM
>> To: Discussion of precise time and frequency measurement
>> Subject: [time-nuts] TBolt Monitor
>>
>> Hi,
>> I have been having fun with my TBolt, and I am organising a
>> power supply to run it off a 12 volt battery backed up power supply.
>> I am making my own low headroom regulators, I assume it will
>> perform better with precisely controlled supply voltages.
>> What I need next is a monitor to show the current UTC time
>> and perhaps a monitor function or two.
>> That will be used to set  a PPS counting clock which is for
>> setting my clocks while I use the 10 MHz to drive a time
>> stamping logger that records the timing of the escapements of
>> the clocks (pendulum type) being analysed.
>> I saw the monitor Didier was proposing, but my skills with
>> micros are quite limited so are there any suggestions for a
>> low power, simple monitor that I can recover UTC with to set
>> my PPS counting clock? The clock will be either or both of a
>> seconds indicating slave dial and a 6 digit large LED display.
>> cheers,
>> Neville Michie
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com To unsubscribe,
>> go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ 
> time-nuts
> and follow the instructions there.



From didier at cox.net  Sun Oct  5 21:07:00 2008
From: didier at cox.net (Didier Juges)
Date: Sun, 5 Oct 2008 20:07:00 -0500
Subject: [time-nuts] THUNBERBOLT PACKET 0X8F-AB
In-Reply-To: <0DFB62B49F744B9192C5A5ADA474ADE0@whe7d219f70f9a>
References: <0DFB62B49F744B9192C5A5ADA474ADE0@whe7d219f70f9a>
Message-ID: <9D85BFFB0F8048B29040F6E6475B59B4@didierhp>

Hank,

You can look at the source code for my Tbolt Monitor to see how I dealt with
that. The link to the source code is in my wiki page:

http://www.ko4bb.com/dokuwiki/doku.php?id=precision_timing:gps_monitor

Didier KO4BB 

> -----Original Message-----
> From: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Hank
> Sent: Sunday, October 05, 2008 2:26 PM
> To: time-nuts at febo.com
> Subject: Re: [time-nuts] THUNBERBOLT PACKET 0X8F-AB
> 
> Ed,
> 
> Got it....Found the spec !  Thanks for the hint !
> 
> Hank
> 
> 
> 
> "The bytes in the data string can have any value. To prevent 
> confusion with the frame
> 
> sequences <DLE> <ID> and <DLE> <ETX>, every <DLE> byte in the 
> data string is
> 
> preceded by an extra <DLE> byte ('stuffing'). These extra 
> <DLE> bytes must be added
> 
> ('stuffed') before sending a packet and removed after 
> receiving the packet."
> 
>   ----- Original Message -----
>   From: Hank
>   To: time-nuts at febo.com
>   Sent: Sunday, October 05, 2008 3:17 PM
>   Subject: [time-nuts] THUNBERBOLT PACKET 0X8F-AB
> 
> 
>   Ed
>   Per your message : That would be the 'byte stuffing' 
> inherent in TSIP packet structure.
> 
>   Packet 0X8F-AB is specified as being 17 bytes including the 
> subcode ( 8F)
>   Do you mean that you cant depend on that packet  always 
> being 17 bytes ?
>   I'm getting 18 bytes only when the time has 16 seconds in 
> it. ( the second byte is duplicated )
> 
>   If you cant depend on having a constant number of bytes ( 
> as defined in the spec ) , how do you then decode it ?
> 
>   Thanks
>   Hank
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com To unsubscribe, 
> go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.



From didier at cox.net  Sun Oct  5 21:13:02 2008
From: didier at cox.net (Didier Juges)
Date: Sun, 5 Oct 2008 20:13:02 -0500
Subject: [time-nuts] TBolt Monitor
In-Reply-To: <768835EB-4675-4E19-8971-7C2C9098ADA6@gmail.com>
References: <33928620-888F-48A0-9F52-6427F5F0BEED@gmail.com><5A4EFAE4A47A4D428BED3350ECF22BED@didierhp>
	<768835EB-4675-4E19-8971-7C2C9098ADA6@gmail.com>
Message-ID: <03A6F2CF0F504F9DA5B0D8F919CEBDDB@didierhp>

 

> -----Original Message-----
> From: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Neville Michie
> Sent: Sunday, October 05, 2008 5:20 PM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] TBolt Monitor
> 
> The clock displays are of two types. The analogue dials use 
> alternate negative and positive pulses and are easily 
> generated with a 0.5 Hz square wave signal. These dials are 
> either slaves from master clock systems or a cheap quartz 
> clock dial with leads to the driver coil. A totem pole driver 
> drives a capacitor that delivers the appropriate impulse to 
> the dial motor. This can be conveniently generated by a PPS 
> signal straight from the TBolt.
> The other display is a series of decimal counters decoded to 
> produce a 60 X 60 X 24 display. This also can be driven from 
> the PPS from the TBolt.
> The problem is setting either clock to UTC (or local time). A 
> pulse counting system can always either miss a pulse or 
> respond to a glitch to get the count out of sequence. A two 
> phase clocking system can reduce this problem but there still 
> remains the problem of start up and confidence checking.
> The TBolt could just drive the displays directly, but loss of 
> signal or power drop-out requires a procedure to 
> resynchronise the indicators and it would be better to have 
> the displays autonomous in the absence of the GPS timing. I 
> am thinking of a TCXO to carry over the timing for long power 
> failures, that can be done with a milliwatt.
> Leap seconds are another consideration, so what I think might 
> be most useful is a BCD seconds output from the monitor.
> This could be jammed into the pulse counter to correct it and 
> could be decoded to give one minute pips like WWV to set an 
> analogue dial.
> Just having a low power monitor indicating UTC is 99% of the 
> required solution.
> All of this is the alternative to running a PC to support the 
> TBolt and so avoid the power demand and inconvenient size of the PC.
> So what I want is a tiny black box to connect to the TBolt 
> that would indicate UTC. Constructing a micro project is no 
> problem, but the program development and installation is a 
> sticking point.
> cheers, Neville Michie
> 

Neville,

All this is quite feasible, but would require more time and motivation than
I have for this at the moment.
However, the Tbolt Monitor outputs GPS time on its display, and it would be
easy to output the time and/or date in BCD in sync with the GPS packets on
the serial port, or in an serial SPI format.

I anticipate having a real PWB for the Tbolt Monitor in a month or two, if
you can wait, that will be an easy fix.

Didier KO4BB



From mfeher at eozinc.com  Sun Oct  5 21:34:45 2008
From: mfeher at eozinc.com (Mike Feher)
Date: Sun, 5 Oct 2008 21:34:45 -0400
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
In-Reply-To: <03A6F2CF0F504F9DA5B0D8F919CEBDDB@didierhp>
References: <33928620-888F-48A0-9F52-6427F5F0BEED@gmail.com><5A4EFAE4A47A4D428BED3350ECF22BED@didierhp><768835EB-4675-4E19-8971-7C2C9098ADA6@gmail.com>
	<03A6F2CF0F504F9DA5B0D8F919CEBDDB@didierhp>
Message-ID: <2D3C7CD387614F5F8D3521363034E0F0@gsmacdq14es>

The attached URL is a 11 day plot of a 30.5 GHz carrier taken every minute
by an Agilent 53152A microwave counter. The Mini-T has an ovenized
oscillator. It appears that the GPS attempts to over correct the oscillator,
hence the large frequency excursions. The real large excursions, around the
96 hour range, were due to a loose connector. The requirements are such that
over a 90 day period the total frequency drift shall be no more than 1 KHz.
Someone in their ultimate wisdom, decided that since they do not have the
time to take measurements for 90 days, they will take it for 24 hours and
not allow any frequency excursions over 11 Hz at 30.5 GHz. Obviously, this
plot does not pass their requirement. When the oscillator is allowed to free
run, the frequency jumps are not there. Has any one else made any
measurements on the Trimble Mini-T. Any observations or suggestions are
appreciated. Regards - Mike

http://www.eozinc.com/11dayplot.pdf

 
Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960
 
 



From Murray.Greenman at rakon.com  Sun Oct  5 22:27:28 2008
From: Murray.Greenman at rakon.com (Murray Greenman)
Date: Mon, 6 Oct 2008 15:27:28 +1300
Subject: [time-nuts] Mains and TV 50Hz
In-Reply-To: <mailman.301.1223255245.2205.time-nuts@febo.com>
References: <mailman.301.1223255245.2205.time-nuts@febo.com>
Message-ID: <BE50C3A72EBA61449C804B2C8B4AE381D05951@NEPTUNE.rakon.net>

Hal and others,

I am sure that if one could accumulate mains cycles long enough, a
reasonable level of accuracy could be obtained, but you need to ask
yourself (1) to what standard is this 'reference' traceable, and (2)
what happens if there is a power failure?

On this latter point, let's say that a clock driven by the mains is
correct to within 10 seconds/day (about 1e-4), but in the longer term
accuracy is improved. To reach even 1ppm level, you need to accumulate
time for 100 days. What chance is there of accumulating for 100 days
without a power failure?

About the TV system, in New Zealand (and no doubt other countries using
the PAL standard) the field frequency is specified to be 50Hz (frame
frequency 25Hz). Unlike NTSC, everything except the colour burst
frequency (4433618.75Hz) can be derived directly from 1MHz by binary
division, which is really handy.

Whether the transmitted frequency is accurately 50Hz depends on the
network. Some of them are quite poor (i.e. worse than 1ppm), but I know
that TVNZ operate their North Island network from a Trimble Thunderbolt
in each studio, which controls a digital mixing desk. While there is
delay managed within the network, the transmitted line and frame
frequency is constant and also related to the GPS second. For many years
the government labs in Wellington measured and published monthly figures
of the error in the TV reference.

Perversely, some of the smaller networks have highly accurate vision
carrier frequencies (allows for channel reuse), but poorly controlled
sync!

Regards,
Murray ZL1BPU



From namichie at gmail.com  Sun Oct  5 22:25:13 2008
From: namichie at gmail.com (Neville Michie)
Date: Mon, 6 Oct 2008 13:25:13 +1100
Subject: [time-nuts] TBolt Monitor
In-Reply-To: <03A6F2CF0F504F9DA5B0D8F919CEBDDB@didierhp>
References: <33928620-888F-48A0-9F52-6427F5F0BEED@gmail.com><5A4EFAE4A47A4D428BED3350ECF22BED@didierhp>
	<768835EB-4675-4E19-8971-7C2C9098ADA6@gmail.com>
	<03A6F2CF0F504F9DA5B0D8F919CEBDDB@didierhp>
Message-ID: <886FDE89-09A0-4CDE-9299-4C0C657F9841@gmail.com>

Hi Didier,
a time (GPS) and date display would be excellent, the only really  
useful enhancement might be a
60th second output, one pulse per minute. That would enable quite a  
few useful timing functions
in conjunction with the PPS signal. Outputting the formatted time  
data may start to get very specific to
a project, but the pulse per minute overcomes a major part of the  
problem of identifying which pulse is
which with the PPS at little cost to the project.
Neville Michie




On 06/10/2008, at 12:13 PM, Didier Juges wrote:

>
>
>> -----Original Message-----
>> From: time-nuts-bounces at febo.com
>> [mailto:time-nuts-bounces at febo.com] On Behalf Of Neville Michie
>> Sent: Sunday, October 05, 2008 5:20 PM
>> To: Discussion of precise time and frequency measurement
>> Subject: Re: [time-nuts] TBolt Monitor
>>
>> The clock displays are of two types. The analogue dials use
>> alternate negative and positive pulses and are easily
>> generated with a 0.5 Hz square wave signal. These dials are
>> either slaves from master clock systems or a cheap quartz
>> clock dial with leads to the driver coil. A totem pole driver
>> drives a capacitor that delivers the appropriate impulse to
>> the dial motor. This can be conveniently generated by a PPS
>> signal straight from the TBolt.
>> The other display is a series of decimal counters decoded to
>> produce a 60 X 60 X 24 display. This also can be driven from
>> the PPS from the TBolt.
>> The problem is setting either clock to UTC (or local time). A
>> pulse counting system can always either miss a pulse or
>> respond to a glitch to get the count out of sequence. A two
>> phase clocking system can reduce this problem but there still
>> remains the problem of start up and confidence checking.
>> The TBolt could just drive the displays directly, but loss of
>> signal or power drop-out requires a procedure to
>> resynchronise the indicators and it would be better to have
>> the displays autonomous in the absence of the GPS timing. I
>> am thinking of a TCXO to carry over the timing for long power
>> failures, that can be done with a milliwatt.
>> Leap seconds are another consideration, so what I think might
>> be most useful is a BCD seconds output from the monitor.
>> This could be jammed into the pulse counter to correct it and
>> could be decoded to give one minute pips like WWV to set an
>> analogue dial.
>> Just having a low power monitor indicating UTC is 99% of the
>> required solution.
>> All of this is the alternative to running a PC to support the
>> TBolt and so avoid the power demand and inconvenient size of the PC.
>> So what I want is a tiny black box to connect to the TBolt
>> that would indicate UTC. Constructing a micro project is no
>> problem, but the program development and installation is a
>> sticking point.
>> cheers, Neville Michie
>>
>
> Neville,
>
> All this is quite feasible, but would require more time and  
> motivation than
> I have for this at the moment.
> However, the Tbolt Monitor outputs GPS time on its display, and it  
> would be
> easy to output the time and/or date in BCD in sync with the GPS  
> packets on
> the serial port, or in an serial SPI format.
>
> I anticipate having a real PWB for the Tbolt Monitor in a month or  
> two, if
> you can wait, that will be an easy fix.
>
> Didier KO4BB
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ 
> time-nuts
> and follow the instructions there.



From didier at cox.net  Sun Oct  5 23:11:45 2008
From: didier at cox.net (Didier Juges)
Date: Sun, 5 Oct 2008 22:11:45 -0500
Subject: [time-nuts] TBolt Monitor
In-Reply-To: <886FDE89-09A0-4CDE-9299-4C0C657F9841@gmail.com>
References: <33928620-888F-48A0-9F52-6427F5F0BEED@gmail.com><5A4EFAE4A47A4D428BED3350ECF22BED@didierhp><768835EB-4675-4E19-8971-7C2C9098ADA6@gmail.com><03A6F2CF0F504F9DA5B0D8F919CEBDDB@didierhp>
	<886FDE89-09A0-4CDE-9299-4C0C657F9841@gmail.com>
Message-ID: <D0D32D534FC84F53BE9B3FD1F00BD66C@didierhp>

 

> -----Original Message-----
> From: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Neville Michie
> Sent: Sunday, October 05, 2008 9:25 PM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] TBolt Monitor
> 
> Hi Didier,
> a time (GPS) and date display would be excellent, the only 
> really useful enhancement might be a 60th second output, one 
> pulse per minute. That would enable quite a few useful timing 
> functions in conjunction with the PPS signal. Outputting the 
> formatted time data may start to get very specific to a 
> project, but the pulse per minute overcomes a major part of 
> the problem of identifying which pulse is which with the PPS 
> at little cost to the project.
> Neville Michie
> 

Neville,

That can be arranged. To make that pulse precisely synchronous with the 1PPS
pulse, a single D flip-flop will be required in addition to the circuit
published on the Tbolt Monitor page.

I may even use the GPS offset to make the pulse synchronous with UTC...

Unlike the PPS pulse (which is very narrow), the PPM pulse will be several
hundred milliseconds so that it could drive an LED directly and be visible.

Remind me of it when the board becomes available.

Didier KO4BB 



From gretchendenisebaxter at gmail.com  Mon Oct  6 10:30:06 2008
From: gretchendenisebaxter at gmail.com (Gretchen Baxter)
Date: Mon, 6 Oct 2008 10:30:06 -0400
Subject: [time-nuts] Does the EU or another European country have an
	equivalent of http://www.usno.navy.mil ?
Message-ID: <4fdb424f0810060730s31107bc6k319d994895433be@mail.gmail.com>

Hi,

I am doing research for my employer around time synchronization.

I have found a lot of good information at http://www.usno.navy.mil

But does the EU or other European countries have a similar source?

As a European company, my employer would prefer not to base too much of its
research around a US Military source, irrelevant how reliable it is.

Thank you,

Gretchen

From dave.g0dja at tiscali.co.uk  Mon Oct  6 11:00:15 2008
From: dave.g0dja at tiscali.co.uk (David Ackrill)
Date: Mon, 06 Oct 2008 16:00:15 +0100
Subject: [time-nuts] Does the EU or another European country have
 an	equivalent of http://www.usno.navy.mil ?
In-Reply-To: <4fdb424f0810060730s31107bc6k319d994895433be@mail.gmail.com>
References: <4fdb424f0810060730s31107bc6k319d994895433be@mail.gmail.com>
Message-ID: <48EA27FF.3050504@tiscali.co.uk>

Gretchen Baxter wrote:
> Hi,
> 
> I am doing research for my employer around time synchronization.
> 
> I have found a lot of good information at http://www.usno.navy.mil
> 
> But does the EU or other European countries have a similar source?

Several universities and scientific organisations in various countries 
in Europe have information on time synchronisation.  A few of the ones I 
know of are as follows.

http://wwp.greenwichmeantime.com/
http://www.srcf.ucam.org/~jsm28/british-time/

http://www.ptb.de/index_en.html (see working group 4.41 at 
http://www.ptb.de/en/org/4/44/441/_index.htm  )

I'm sure there must be more, but you may need to use Google to find them.

Dave








From magnus at rubidium.dyndns.org  Mon Oct  6 12:07:43 2008
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Mon, 6 Oct 2008 18:07:43 +0200 (CEST)
Subject: [time-nuts] Does the EU or another European country have an
 equivalent of http://www.usno.navy.mil ?
In-Reply-To: <4fdb424f0810060730s31107bc6k319d994895433be@mail.gmail.com>
References: <4fdb424f0810060730s31107bc6k319d994895433be@mail.gmail.com>
Message-ID: <2fd15c3de2836f490e80c4c55ef810b8.squirrel@rubidium.dyndns.org>

Gretchen,

> I am doing research for my employer around time synchronization.
>
> I have found a lot of good information at http://www.usno.navy.mil
>
> But does the EU or other European countries have a similar source?
>
> As a European company, my employer would prefer not to base too much of
> its
> research around a US Military source, irrelevant how reliable it is.
>
> Thank you,

What type of information do you need? There are several very good sources,
but what field within time synchronization do you need?

Telecom networks? Internet? Precission GPS/GNSS? Low phase noise?

With a little more info I am sure we can give you better directions.

Best regards,
Magnus


From scmcgrath at gmail.com  Mon Oct  6 12:08:22 2008
From: scmcgrath at gmail.com (Scott McGrath)
Date: Mon, 6 Oct 2008 12:08:22 -0400
Subject: [time-nuts] GPS, NTP, and Cisco routers...
In-Reply-To: <1c096fd70810051954j6fd86339m3fd94647300ede65@mail.gmail.com>
References: <3C932D37-8120-4833-81D8-9AC8C1E73434@rob-vassar.com>
	<1c096fd70810042200y29299335n2e75c5c34b574b79@mail.gmail.com>
	<c9ffea950810050943x145e719m25daa3c6a3ca361f@mail.gmail.com>
	<1c096fd70810050958s624a4604t38ebbadf74e1af9c@mail.gmail.com>
	<c9ffea950810051128o4f622495u9879711460a46234@mail.gmail.com>
	<1c096fd70810051954j6fd86339m3fd94647300ede65@mail.gmail.com>
Message-ID: <c9ffea950810060908v6281c7d5v9813c5095c567083@mail.gmail.com>

The Oscillator on a 25xx is a Saronix 3.864Mhz oscillator chip.   Also see this


This is from one of Cisco's configuration guides - my documentation
unfortunately was covered by a Cisco NDA I am looking for a public
document which describes serial interrupt handling.    But when you
think about it input must also have a interrupt handler otherwise one
would never be able to send a break sequence and have it acted upon.



!--- Reduce async framing overhead to improve throughput.

 speed 115200

!--- The AUX port on the 2600 supports a speed of 115200.
!--- Note: If you route through the AUX port, each character generates a
!--- processor interrupt. This is an abnormally high load on the CPU,
!--- which can be resolved if you use a lower AUX port speed.

 flowcontrol hardware

!--- This configures RTS/CTS flow control.



On Sun, Oct 5, 2008 at 10:54 PM, Dave hartzell <hartzell at gmail.com> wrote:
> Hmmm...
>
> I would be interested to see those docs.
>
> I find it hard to believe that a pin going high on a serial port would
> generate an interrupt unless a process is listening to it.
>
> Its not that I don't believe you, I just have never run into this in
> my 12+ years dealing with Cisco.  Output logging crashes for sure, but
> never anything with terminal servers.
>
> Scary stuff.  I'm going to unplug all my consoles now!  ;-)
>
>
> On Sun, Oct 5, 2008 at 11:28 AM, Scott McGrath <scmcgrath at gmail.com> wrote:
>> Interrupts happen on any serial operation I'll dig out the relevant
>> doc's as another interesting way to crash a 6509 is to have a terminal
>> server randomly generating text.   Been there, got the scars... and
>> the root cause analysis from TAC...
>>
>>
>


From gretchendenisebaxter at gmail.com  Mon Oct  6 12:39:06 2008
From: gretchendenisebaxter at gmail.com (Gretchen Baxter)
Date: Mon, 6 Oct 2008 12:39:06 -0400
Subject: [time-nuts] Does the EU or another European country have an
	equivalent of http://www.usno.navy.mil ?
In-Reply-To: <2fd15c3de2836f490e80c4c55ef810b8.squirrel@rubidium.dyndns.org>
References: <4fdb424f0810060730s31107bc6k319d994895433be@mail.gmail.com>
	<2fd15c3de2836f490e80c4c55ef810b8.squirrel@rubidium.dyndns.org>
Message-ID: <4fdb424f0810060939x2dc23e7fw368d7b0b1b21ce7c@mail.gmail.com>

Just looking for basic info and technical info, but with a source I can
quote from the EU community, not US military.

Mainly around basic network time syncronization.

And GPS / Galileo.

thanx!








On Mon, Oct 6, 2008 at 12:07 PM, Magnus Danielson <
magnus at rubidium.dyndns.org> wrote:

> Gretchen,
>
> > I am doing research for my employer around time synchronization.
> >
> > I have found a lot of good information at http://www.usno.navy.mil
> >
> > But does the EU or other European countries have a similar source?
> >
> > As a European company, my employer would prefer not to base too much of
> > its
> > research around a US Military source, irrelevant how reliable it is.
> >
> > Thank you,
>
> What type of information do you need? There are several very good sources,
> but what field within time synchronization do you need?
>
> Telecom networks? Internet? Precission GPS/GNSS? Low phase noise?
>
> With a little more info I am sure we can give you better directions.
>
> Best regards,
> Magnus
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

From w3kl at w3kl.com  Mon Oct  6 13:03:03 2008
From: w3kl at w3kl.com (Jeffrey Okamitsu)
Date: Mon, 6 Oct 2008 10:03:03 -0700 (PDT)
Subject: [time-nuts] Further Observation On My 5061B
Message-ID: <740498.62618.qm@web35407.mail.mud.yahoo.com>

I forgot to mention in my email yesterday that when I did a degaussing procedure (using the 10638A) the Beam current peaked above 20 nA during the early part of the procedure.
?
At first, I took this an evidence that more beam current could be obtained - that is, the mass spec system needed to be tuned.? However, upon further thought I suspect that what I was seeing was inductive pickup by the beam current measuring system.
?
Anyone care to speculate?
?
Jeff

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

From w3kl at w3kl.com  Mon Oct  6 13:24:05 2008
From: w3kl at w3kl.com (Jeffrey Okamitsu)
Date: Mon, 6 Oct 2008 10:24:05 -0700 (PDT)
Subject: [time-nuts] Further Observation On My 5061B
In-Reply-To: <740498.62618.qm@web35407.mail.mud.yahoo.com>
Message-ID: <149887.22751.qm@web35404.mail.mud.yahoo.com>

Also, the magnitude of the "bump" decreased over time, with is consistent with the way the degausser works - the current pulse decreases exponentially with time.
?
Jeff

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

--- On Mon, 10/6/08, Jeffrey Okamitsu <w3kl at w3kl.com> wrote:

From: Jeffrey Okamitsu <w3kl at w3kl.com>
Subject: [time-nuts] Further Observation On My 5061B
To: time-nuts at febo.com
Date: Monday, October 6, 2008, 1:03 PM

I forgot to mention in my email yesterday that when I did a degaussing procedure
(using the 10638A) the Beam current peaked above 20 nA during the early part of
the procedure.
?
At first, I took this an evidence that more beam current could be obtained -
that is, the mass spec system needed to be tuned.? However, upon further
thought I suspect that what I was seeing was inductive pickup by the beam
current measuring system.
?
Anyone care to speculate?
?
Jeff

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402
_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

From mark.allwright at bell.ca  Mon Oct  6 13:47:55 2008
From: mark.allwright at bell.ca (mark.allwright at bell.ca)
Date: Mon, 6 Oct 2008 13:47:55 -0400
Subject: [time-nuts] GPS, NTP, and Cisco routers...
In-Reply-To: <48E8FA43.2070701@intt.net>
References: <3C932D37-8120-4833-81D8-9AC8C1E73434@rob-vassar.com>
	<1c096fd70810042200y29299335n2e75c5c34b574b79@mail.gmail.com>
	<c9ffea950810050943x145e719m25daa3c6a3ca361f@mail.gmail.com>
	<48E8FA43.2070701@intt.net>
Message-ID: <B31D71BD33D42846B7C73055574E21A013101C2B@MBX06.bell.corp.bce.ca>

I remember running this on "line aux 0" in the IOS version 11.x days (circa 1999).  Was supported on the 7000, 4000 and 2500 series routers.  It was originally designed for a Telecom Solutions (bought by Symmetricom) clock that would be co-located with the routers in a data centre .  I have a PDF copy of "Application Note 600" that shows how it was intended to be used (mail me if you need a copy).  I ditched the solution in favour of a FreeBSD+GPS based solution; Cisco was (and still is) only supporting version 3 of NTP specification.  I do not have any data left on how well it worked but I recall it was better with the PPS support than without.

Regards.

Mark.


--
Mark Allwright CCIE #1088

National Hosting Services - Senior Data Analyst
2100 111 - 5th Avenue SW
Calgary, AB T2P 3Y6

T: 403 410-0733 | F: 403 216-6050



-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On Behalf Of Scott Mace
Sent: Sunday, October 05, 2008 11:33 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] GPS, NTP, and Cisco routers...

This runs on the aux port, and the sup720 doesn't have an aux port...
There are always obscure features that slip into the production releases that aren't tested and they just forget to exclude them during builds.
TAC will probably have no clue about this...
You could try the cisco-nsp mailling list for support, but beware, it's frequented by cisco developers that will just as soon open a bug-id to drop 'feature' from the production release if it was never supposed to be there in the first place.

I wonder if this was originally used as an alternative method to time the MIX midplane in the VXR chassis and the NTP feature was side benefit?  Most telecom gear that needs synchronization will take a BITS input or some other frequency reference.  I've used that extensively with SONET gear and the good old Datum OT-21.  I never used the 7200 MIX, so I'm not sure if it could take an external reference or just recover clock from a DS1 port.

Seems like a good use for an AUX port if you don't need a modem or reverse telnet!

        Scott

Scott McGrath wrote:
> Actually you might get pretty good results if you have a 6509 as any
> activity on the serial port triggers a CPU interrupt which is why on a
> overloaded 6509 the first thing to try is "no logging console" to get
> the cpu down from 100% - usually in the context of DDoS and the
> control plane is slammed as the EOBC is only a 1 megabit channel even
> on the 3BXL's.    This is one of the advantages of the annual trek out
> to Bldg 14 in San Jose - one gets to meet the guys who developed the
> code for the routers.
>
> This has more than passing interest for me as one could take a NovaTel
> GPSCard which has a 1PPS output and runs on a single 12-36V supply and
> has a dedicated 1PPS output at serial levels and install one at each
> router location.    Still have not disassembled the 2501 and 2611 to
> see which cheapo TCXO Cisco has installed.
>
>
> What do you have available at your shop - we are running SUP720-3BXL's
> running 12.2 SXF
>
> On Sun, Oct 5, 2008 at 1:00 AM, Dave hartzell <hartzell at gmail.com> wrote:
>> Looks like Trimble and Cisco got together on a PPS implementation for
>> the 7200, starting with 12.0T trainwreck:
>>
>> http://www.cisco.com/en/US/docs/ios/12_1t/12_1t1/feature/guide/dtrimb
>> le.html
>>
>> Since I don't have any 7200s any longer (thank goodness), I checked
>> and it seems that the 6500s support this as well on the console
>> serial
>> port:
>>
>> 6509-rtr(config-line)#ntp ?
>>  pps-discipline  Use PPS pulse to discipline system clock
>>  refclock        NTP Reference Clock
>>
>> and
>>
>> 6509-rtr(config-line)#ntp refclock ?
>>  telecom-solutions  Telecom Solutions GPS
>>  trimble            Trimble Navigation TSIP Protocol
>>
>> It looks interesting, and if the code is just looking for a PPS
>> transition on the CTS or RI, you might be in luck with any external
>> PPS...
>>
>> BUT be forewarned, IOS is a cooperative multitasking operating system
>> (at least prior to the new "modular" stuff), so your accuracy is
>> going to vary depending on loads, processes, etc.  I wouldn't count
>> on this being to spectacular...  probably no better than an external
>> NTP source.
>>
>> And of course, you can always call the TAC for more assistance!  ;-)
>>
>> 73,
>> Dave
>> AF6KD
>>
>>
>> On Fri, Oct 3, 2008 at 2:39 PM, Robert Vassar <rvassar at rob-vassar.com> wrote:
>>>
>>>
>>> I've been fiddling around with an old Cisco router here at the house
>>> to brush up.  We have an IPv6 project going at work, and our WAN
>>> provider provides no native transit, so I'm looking at doing some
>>> tunneling.  Anyhow... I discovered IOS 12.1 and above have native
>>> NTP capability.  I don't have the exhaustive IOS command reference,
>>> and I suspect it's a limited NTP implementation. I'm wondering if
>>> it's possible to tie a GPS unit to a router serial port and gain a
>>> stratum 0 refclock.
>>>
>>>
>>> Any Cisco guru's on the list?  :-)
>>>
>>>
>>>
>>> Cheers,
>>>
>>> Rob
>>>
>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to
>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>

_______________________________________________
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From mctylr at gmail.com  Mon Oct  6 14:38:57 2008
From: mctylr at gmail.com (michael taylor)
Date: Mon, 6 Oct 2008 15:38:57 -0300
Subject: [time-nuts] Does the EU or another European country have an
	equivalent of http://www.usno.navy.mil ?
In-Reply-To: <4fdb424f0810060939x2dc23e7fw368d7b0b1b21ce7c@mail.gmail.com>
References: <4fdb424f0810060730s31107bc6k319d994895433be@mail.gmail.com>
	<2fd15c3de2836f490e80c4c55ef810b8.squirrel@rubidium.dyndns.org>
	<4fdb424f0810060939x2dc23e7fw368d7b0b1b21ce7c@mail.gmail.com>
Message-ID: <25630a120810061138w2b3bb9cah25eedc04170c2d61@mail.gmail.com>

On Mon, Oct 6, 2008 at 1:39 PM, Gretchen Baxter
<gretchendenisebaxter at gmail.com> wrote:
> Just looking for basic info and technical info, but with a source I can
> quote from the EU community, not US military.
>
> Mainly around basic network time syncronization.

In most EU countries, I believe their "national labs" or "bureau of
weights & measures" are the domestic source for national standards.
For example in the UK the National Physical Labs (NPL) have a Time &
Frequency branch, <http://www.npl.co.uk/server.php?show=nav.294>.

I suspect you will also be interested in BIPM, who coordinate
International Atomic Time (TAI) and well as Coordinated Universal Time
(UTC). <http://www.bipm.org/en/scientific/tai/>.

For English and French publications, you can also refer to Canada's
National Research Council - Institute for National Measurement
Standards NRC-INMS Frequency & Time group
<http://inms-ienm.nrc-cnrc.gc.ca/time_services/time_services_e.html>,

I suspect most of the information on Galileo should be available from
the ESA and EU.

-Michael


From wje at quackers.net  Mon Oct  6 17:47:23 2008
From: wje at quackers.net (wje)
Date: Mon, 06 Oct 2008 17:47:23 -0400
Subject: [time-nuts] Further Observation On My 5061B
In-Reply-To: <149887.22751.qm@web35404.mail.mud.yahoo.com>
References: <149887.22751.qm@web35404.mail.mud.yahoo.com>
Message-ID: <48EA876B.3000308@quackers.net>

Just a nitpick - the reading on the meter isn't any particular scale, 
it's essentially arbitrary.
The actual beam current is typically in the picoamp range. My measured 
beam current is only about 400 pA.

I'm not sure what you would be seeing from induction; the beam current 
is a result of current flow from the electron multiplier, which is 
stimulated by electrons from the ionized cesium. There are no inductive 
components, and in any case the frequency of the degaussing is so low 
(0.2 Hz) that any inductive coupling would be extremely low.

My guess would be that you actually have an at-least marginally working 
tube, but have a failure in your synthesizer, or in the microwave 
generator. Have you done the harmonic generator alignment in the manual? 
I don't remember if you said if you did the LF test, that's a good 
diagnostic also. If you have a high impedance voltmeter, (100 megs), you 
can directly measure the beam current following the procedure in the 
manual. This will eliminate any problems in the amps and detector. Go to 
open-loop, mod-off, monitor the current and very slowly adjust the 
coarse 10Mhz. You should see variation at resonance peaks.

BTW, even when operating correctly, you have to be quite precise when 
doing the coarse frequency adjustment; the peaks are very narrow and 
easy to miss.

One final thing you can do is to go to open-loop, mod-on, amplifier gain 
switch to high and crank the gain up as far as you can, but not to 
exceed a second-harmonic reading of 40. Then, slowly adjust the 10Mhz 
coarse control and see if the second-harmonic moves anywhere over the 
control range. If you get a signal, back off on the gain and keep 
tweaking the osc to maximize the second harmonic. If you can do this, 
you are getting a beam signal, and if you can get a second-harmonic 
reading of at least 30, you should be able to get lock, assuming your 
synthesizer is working. It's also easy to end up on a secondary peak, in 
which case you will get good readings but no lock. I always adjust past 
the first peak I see to look for a secondary. If I don't find it, I know 
I was on a secondary originally and scan back to maximize the beam 
current. Again, there's not a huge difference between primary and 
secondary peaks, so you have to pay attention.

Bill Ezell
----------
They said 'Windows or better'
so I used Linux.



Jeffrey Okamitsu wrote:
> Also, the magnitude of the "bump" decreased over time, with is consistent with the way the degausser works - the current pulse decreases exponentially with time.
>  
> Jeff
>
> Jeffrey K. Okamitsu, PhD, MBA
> +1-609-638-5402
>
> --- On Mon, 10/6/08, Jeffrey Okamitsu <w3kl at w3kl.com> wrote:
>
> From: Jeffrey Okamitsu <w3kl at w3kl.com>
> Subject: [time-nuts] Further Observation On My 5061B
> To: time-nuts at febo.com
> Date: Monday, October 6, 2008, 1:03 PM
>
> I forgot to mention in my email yesterday that when I did a degaussing procedure
> (using the 10638A) the Beam current peaked above 20 nA during the early part of
> the procedure.
>  
> At first, I took this an evidence that more beam current could be obtained -
> that is, the mass spec system needed to be tuned.  However, upon further
> thought I suspect that what I was seeing was inductive pickup by the beam
> current measuring system.
>  
> Anyone care to speculate?
>  
> Jeff
>
> Jeffrey K. Okamitsu, PhD, MBA
> +1-609-638-5402
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>
>   


From w3kl at w3kl.com  Mon Oct  6 18:03:18 2008
From: w3kl at w3kl.com (Jeffrey Okamitsu)
Date: Mon, 6 Oct 2008 15:03:18 -0700 (PDT)
Subject: [time-nuts] Further Observation On My 5061B
In-Reply-To: <48EA876B.3000308@quackers.net>
Message-ID: <925832.74972.qm@web35405.mail.mud.yahoo.com>

Bill.? Thanks for the info.
?
Yep, did the microwave alignment as per the manual.? And, I understand how sensitive it is to find the true peak and that there is very little difference between the primary and secondary peaks.? I am sure I am on the primary peak.
?
I will try working with the loop amplifier sometime this week and let you know what I find.
?
Thanks!
?
Jeff

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

--- On Mon, 10/6/08, wje <wje at quackers.net> wrote:

From: wje <wje at quackers.net>
Subject: Re: [time-nuts] Further Observation On My 5061B
To: "Discussion of precise time and frequency measurement" <time-nuts at febo.com>
Date: Monday, October 6, 2008, 5:47 PM

Just a nitpick - the reading on the meter isn't any particular scale, 
it's essentially arbitrary.
The actual beam current is typically in the picoamp range. My measured 
beam current is only about 400 pA.

I'm not sure what you would be seeing from induction; the beam current 
is a result of current flow from the electron multiplier, which is 
stimulated by electrons from the ionized cesium. There are no inductive 
components, and in any case the frequency of the degaussing is so low 
(0.2 Hz) that any inductive coupling would be extremely low.

My guess would be that you actually have an at-least marginally working 
tube, but have a failure in your synthesizer, or in the microwave 
generator. Have you done the harmonic generator alignment in the manual? 
I don't remember if you said if you did the LF test, that's a good 
diagnostic also. If you have a high impedance voltmeter, (100 megs), you 
can directly measure the beam current following the procedure in the 
manual. This will eliminate any problems in the amps and detector. Go to 
open-loop, mod-off, monitor the current and very slowly adjust the 
coarse 10Mhz. You should see variation at resonance peaks.

BTW, even when operating correctly, you have to be quite precise when 
doing the coarse frequency adjustment; the peaks are very narrow and 
easy to miss.

One final thing you can do is to go to open-loop, mod-on, amplifier gain 
switch to high and crank the gain up as far as you can, but not to 
exceed a second-harmonic reading of 40. Then, slowly adjust the 10Mhz 
coarse control and see if the second-harmonic moves anywhere over the 
control range. If you get a signal, back off on the gain and keep 
tweaking the osc to maximize the second harmonic. If you can do this, 
you are getting a beam signal, and if you can get a second-harmonic 
reading of at least 30, you should be able to get lock, assuming your 
synthesizer is working. It's also easy to end up on a secondary peak, in 
which case you will get good readings but no lock. I always adjust past 
the first peak I see to look for a secondary. If I don't find it, I know 
I was on a secondary originally and scan back to maximize the beam 
current. Again, there's not a huge difference between primary and 
secondary peaks, so you have to pay attention.

Bill Ezell
----------
They said 'Windows or better'
so I used Linux.



Jeffrey Okamitsu wrote:
> Also, the magnitude of the "bump" decreased over time, with is
consistent with the way the degausser works - the current pulse decreases
exponentially with time.
>  
> Jeff
>
> Jeffrey K. Okamitsu, PhD, MBA
> +1-609-638-5402
>
> --- On Mon, 10/6/08, Jeffrey Okamitsu <w3kl at w3kl.com> wrote:
>
> From: Jeffrey Okamitsu <w3kl at w3kl.com>
> Subject: [time-nuts] Further Observation On My 5061B
> To: time-nuts at febo.com
> Date: Monday, October 6, 2008, 1:03 PM
>
> I forgot to mention in my email yesterday that when I did a degaussing
procedure
> (using the 10638A) the Beam current peaked above 20 nA during the early
part of
> the procedure.
>  
> At first, I took this an evidence that more beam current could be obtained
-
> that is, the mass spec system needed to be tuned.  However, upon further
> thought I suspect that what I was seeing was inductive pickup by the beam
> current measuring system.
>  
> Anyone care to speculate?
>  
> Jeff
>
> Jeffrey K. Okamitsu, PhD, MBA
> +1-609-638-5402
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>
>   

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

From Charlie.Myers at ps.net  Mon Oct  6 21:58:40 2008
From: Charlie.Myers at ps.net (Myers, Charlie)
Date: Mon, 6 Oct 2008 20:58:40 -0500
Subject: [time-nuts] Need Help - Datum 9390 GPS Time Code & Frequency
	Generator
Message-ID: <8C1E01B3C43FF44EAC6658014AB0617A0298031B@PSCDALPEXCH03.perotsystems.net>

I recently obtained a Datum model# 9390-52321 GPS Time Code & Frequency
Generator.  This unit has a Rubidium time base.

 I hooked the unit up to my Motorola GPS2000 GPS antenna (which is
mounted on the roof of my house) and powered the unit up, but I can't
seem to get the unit to see the satellites.  I keep getting the
following error message on the LCD display, "Signal Level Low" followed
by the status message, "GPS Time Not Acquired".

I checked the antenna and transmission line and they seem to be okay
because they operate my HP z3801A GPS time/frequency receiver just fine
and I get plenty of satellite signal level on the HP receiver.  I
checked the +5 volts on the antenna connector on the back of the Datum
unit and that measures correctly.

Does anyone have any ideas where to look or what other tests to perform
to isolate this problem?

Thanks for any assistance you can provide me.

Charlie Myers
WA3RAD

From jmiles at pop.net  Mon Oct  6 22:19:41 2008
From: jmiles at pop.net (John Miles)
Date: Mon, 6 Oct 2008 19:19:41 -0700
Subject: [time-nuts] Need Help - Datum 9390 GPS Time Code &
	FrequencyGenerator
In-Reply-To: <8C1E01B3C43FF44EAC6658014AB0617A0298031B@PSCDALPEXCH03.perotsystems.net>
Message-ID: <PKEGJHPHLLBACEOICCBJAENNMEAB.jmiles@pop.net>

Sounds like you're doing everything right.  9390s are plug-and-play by
nature, so I'd have to wonder if there's some front-end damage to the GPS
receiver.

-- john, KE5FX

> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]On
> Behalf Of Myers, Charlie
> Sent: Monday, October 06, 2008 6:59 PM
> To: time-nuts at febo.com
> Subject: [time-nuts] Need Help - Datum 9390 GPS Time Code &
> FrequencyGenerator
> Importance: High
>
>
> I recently obtained a Datum model# 9390-52321 GPS Time Code & Frequency
> Generator.  This unit has a Rubidium time base.
>
>  I hooked the unit up to my Motorola GPS2000 GPS antenna (which is
> mounted on the roof of my house) and powered the unit up, but I can't
> seem to get the unit to see the satellites.  I keep getting the
> following error message on the LCD display, "Signal Level Low" followed
> by the status message, "GPS Time Not Acquired".
>
> I checked the antenna and transmission line and they seem to be okay
> because they operate my HP z3801A GPS time/frequency receiver just fine
> and I get plenty of satellite signal level on the HP receiver.  I
> checked the +5 volts on the antenna connector on the back of the Datum
> unit and that measures correctly.
>
> Does anyone have any ideas where to look or what other tests to perform
> to isolate this problem?
>
> Thanks for any assistance you can provide me.
>
> Charlie Myers
> WA3RAD
>



From fortime at bellsouth.net  Tue Oct  7 01:00:19 2008
From: fortime at bellsouth.net (phil)
Date: Tue, 7 Oct 2008 01:00:19 -0400
Subject: [time-nuts] Need Help - Datum 9390 GPS Time Code
	&FrequencyGenerator
References: <PKEGJHPHLLBACEOICCBJAENNMEAB.jmiles@pop.net>
Message-ID: <000b01c92839$995214b0$a101a8c0@officemail>

I've had three of those units and all three had different gps 
receiver/boards. Most as John said, are "plug and play', however, all I have 
seen require about 40 ma to be drawn by the antenna to eliminate the antenna 
error on the display after it boots up. Most of those high current antennas 
like the older Trimble's had about 42 db gain. I'm not saying that is the 
problem, but you did say "Signal Level Low".  Most of the antenna error 
problems can be tricked into thinking the antenna is there by paralleling a 
resistor on the antenna/input. (that dosen't solve your present no signal 
problem)

I had one "crap" out a few days ago where the receiver front-end gave up the 
ghost. Most of that vintage electronics loose capacitors with age, possibly 
that is the issue. I was also wondering if a newer receiver could be 
substituted/adapted like the trimble ace 2 or 3.

Oh, a side note, unless it was upgraded just prior to being obsoleted it 
will have the gps week rollover problem. Time and frequency will be fine but 
date and week will be wrong.

Phil


----- Original Message ----- 
From: "John Miles" <jmiles at pop.net>
To: "Discussion of precise time and frequency measurement" 
<time-nuts at febo.com>
Sent: Monday, October 06, 2008 10:19 PM
Subject: Re: [time-nuts] Need Help - Datum 9390 GPS Time Code 
&FrequencyGenerator


> Sounds like you're doing everything right.  9390s are plug-and-play by
> nature, so I'd have to wonder if there's some front-end damage to the GPS
> receiver.
>
> -- john, KE5FX
>
>> -----Original Message-----
>> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]On
>> Behalf Of Myers, Charlie
>> Sent: Monday, October 06, 2008 6:59 PM
>> To: time-nuts at febo.com
>> Subject: [time-nuts] Need Help - Datum 9390 GPS Time Code &
>> FrequencyGenerator
>> Importance: High
>>
>>
>> I recently obtained a Datum model# 9390-52321 GPS Time Code & Frequency
>> Generator.  This unit has a Rubidium time base.
>>
>>  I hooked the unit up to my Motorola GPS2000 GPS antenna (which is
>> mounted on the roof of my house) and powered the unit up, but I can't
>> seem to get the unit to see the satellites.  I keep getting the
>> following error message on the LCD display, "Signal Level Low" followed
>> by the status message, "GPS Time Not Acquired".
>>
>> I checked the antenna and transmission line and they seem to be okay
>> because they operate my HP z3801A GPS time/frequency receiver just fine
>> and I get plenty of satellite signal level on the HP receiver.  I
>> checked the +5 volts on the antenna connector on the back of the Datum
>> unit and that measures correctly.
>>
>> Does anyone have any ideas where to look or what other tests to perform
>> to isolate this problem?
>>
>> Thanks for any assistance you can provide me.
>>
>> Charlie Myers
>> WA3RAD
>>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there. 



From mfeher at eozinc.com  Tue Oct  7 06:36:12 2008
From: mfeher at eozinc.com (Mike Feher)
Date: Tue, 7 Oct 2008 06:36:12 -0400
Subject: [time-nuts] Need Help - Datum 9390 GPS Time Code
	&FrequencyGenerator
In-Reply-To: <PKEGJHPHLLBACEOICCBJAENNMEAB.jmiles@pop.net>
References: <8C1E01B3C43FF44EAC6658014AB0617A0298031B@PSCDALPEXCH03.perotsystems.net>
	<PKEGJHPHLLBACEOICCBJAENNMEAB.jmiles@pop.net>
Message-ID: <16199E5B260348448DEC37276F6FD940@gsmacdq14es>


From Arnold.Tibus at gmx.de  Tue Oct  7 09:07:43 2008
From: Arnold.Tibus at gmx.de (Arnold Tibus)
Date: Tue, 07 Oct 2008 15:07:43 +0200
Subject: [time-nuts] Does the EU or another European country have an
	equivalent of http://www.usno.navy.mil ?
In-Reply-To: <4fdb424f0810060939x2dc23e7fw368d7b0b1b21ce7c@mail.gmail.com>
Message-ID: <mailman.15.1223385000.2202.time-nuts@febo.com>

Gretchen,

I don't know exactly what you need or already know, 
but did you ever look to

PTB Braunschweig (Phys. Techn. Bundesanstalt, Germany)
(http://www.ptb.de/en/org/q/q4/q42/index.htm (engl.))
National Physical Laboratory NPL, UK
(http://www.npl.co.uk/server.php?show=nav.348)
(http://www.atomicclockrugbymsf.co.uk/time-synchronisation.htm)
The International Bureau of Weights and Measures,

Bureau International des Poids et Mesures
 (BIPM) in
France is charged with providing the standard UTC for the
World.
(http://www.bipm.org/static/gpst/)

I hope it will help you going on,
good luck!

Arnold



On Mon, 6 Oct 2008 12:39:06 -0400, Gretchen Baxter wrote:

>Just looking for basic info and technical info, but with a source I can
>quote from the EU community, not US military.

>Mainly around basic network time syncronization.

>And GPS / Galileo.

>thanx!


>On Mon, Oct 6, 2008 at 12:07 PM, Magnus Danielson <
>magnus at rubidium.dyndns.org> wrote:

>> Gretchen,
>>
>> > I am doing research for my employer around time synchronization.
>> >
>> > I have found a lot of good information at http://www.usno.navy.mil
>> >
>> > But does the EU or other European countries have a similar source?
>> >
>> > As a European company, my employer would prefer not to base too much of
>> > its
>> > research around a US Military source, irrelevant how reliable it is.
>> >
>> > Thank you,
>>
>> What type of information do you need? There are several very good sources,
>> but what field within time synchronization do you need?
>>
>> Telecom networks? Internet? Precission GPS/GNSS? Low phase noise?
>>
>> With a little more info I am sure we can give you better directions.
>>
>> Best regards,
>> Magnus
>>
>_______________________________________________
>time-nuts mailing list -- time-nuts at febo.com
>To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>and follow the instructions there.





From gretchendenisebaxter at gmail.com  Tue Oct  7 10:25:04 2008
From: gretchendenisebaxter at gmail.com (Gretchen Baxter)
Date: Tue, 7 Oct 2008 10:25:04 -0400
Subject: [time-nuts] =?windows-1252?q?Where_can_I_find_a_master_list_of_NT?=
	=?windows-1252?q?P_/time_services_RFC=92s=3F?=
Message-ID: <4fdb424f0810070725y445adc3asba2eaf93a5257ffb@mail.gmail.com>

Hi,

Where can I find a master list of NTP /time services RFC's?

Thanx!

From GDowd at symmetricom.com  Tue Oct  7 10:37:43 2008
From: GDowd at symmetricom.com (Greg Dowd)
Date: Tue, 7 Oct 2008 07:37:43 -0700
Subject: [time-nuts] Where can I find a master list of NTP /time
	services RFC's?
In-Reply-To: <4fdb424f0810070725y445adc3asba2eaf93a5257ffb@mail.gmail.com>
References: <4fdb424f0810070725y445adc3asba2eaf93a5257ffb@mail.gmail.com>
Message-ID: <CB45EB047BD43041BF1F4CC7D6DB21BF01792025@sjmail2.symmetricom.com>

There aren't that many.  The current list (www.ietf.org) would include

Daytime (rfc867)
Time (rfc868)
NTP (rfc1305)
SNTP (rfc4330)

There will be a few new ones for ntpv4 (standards for protocol and snmp
mib, informational for autokey) soon but they are still in last call.
Also, the tictoc working group will likely release a few as well.  Note
that time and daytime are really, really old now.



Greg Dowd
gdowd at symmetricom dot com (antispam format)
Symmetricom, Inc.
www.symmetricom.com
"Everything should be made as simple as possible, but no simpler" Albert
Einstein
-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Gretchen Baxter
Sent: Tuesday, October 07, 2008 7:25 AM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] Where can I find a master list of NTP /time
services RFC's?

Hi,

Where can I find a master list of NTP /time services RFC's?

Thanx!
_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.


From hmurray at megapathdsl.net  Tue Oct  7 12:59:46 2008
From: hmurray at megapathdsl.net (Hal Murray)
Date: Tue, 07 Oct 2008 09:59:46 -0700
Subject: [time-nuts] Where can I find a master list of NTP /time
 services RFC's?
In-Reply-To: Message from "Greg Dowd" <GDowd@symmetricom.com> of "Tue,
	07 Oct 2008 07:37:43 PDT."
	<CB45EB047BD43041BF1F4CC7D6DB21BF01792025@sjmail2.symmetricom.com>
Message-ID: <20081007165947.45593BCD5@ip-64-139-1-69.sjc.megapath.net>


> Daytime (rfc867)
> Time (rfc868)
> NTP (rfc1305)
> SNTP (rfc4330)

I think there is another RFC on the kernel API for the PPS stuff.

If you are looking for standards in general rather than just RFCs, there is 
an IEEE (I think) standard that is very NTP like but aimed at much higher 
precision.  It uses hardware assist to time-stamp ethernet packets.  I think 
the target is synchronizing data collection within a lab: LAN rather than WAN.



-- 
These are my opinions, not necessarily my employer's.  I hate spam.





From jherrero at hvsistemas.es  Tue Oct  7 13:16:49 2008
From: jherrero at hvsistemas.es (Javier Herrero)
Date: Tue, 07 Oct 2008 19:16:49 +0200
Subject: [time-nuts] Where can I find a master list of NTP /time
 services RFC's?
In-Reply-To: <20081007165947.45593BCD5@ip-64-139-1-69.sjc.megapath.net>
References: <20081007165947.45593BCD5@ip-64-139-1-69.sjc.megapath.net>
Message-ID: <48EB9981.8060003@hvsistemas.es>

PPSAPI is described in RFC-2873. The IEEE standard for precission 
syncronization is IEEE-1588. Here is a link to an application 
implementing a PTP daemon according to IEEE-1588:

http://ptpd.sourceforge.net

Lot of information about the NTP related RFCs are referenced in 
www.ntp.org although v4 is not yet in the form of RFC.

Regards,

Javier

Hal Murray escribi?:
> I think there is another RFC on the kernel API for the PPS stuff.
>
> If you are looking for standards in general rather than just RFCs, there is 
> an IEEE (I think) standard that is very NTP like but aimed at much higher 
> precision.  It uses hardware assist to time-stamp ethernet packets.  I think 
> the target is synchronizing data collection within a lab: LAN rather than WAN.
>
>
>

-- 
------------------------------------------------------------------------
Javier Herrero                            EMAIL: jherrero at hvsistemas.com
HV Sistemas S.L.                          PHONE:         +34 949 336 806
Los Charcones, 17A                        FAX:           +34 949 336 792
19170 El Casar - Guadalajara - Spain      WEB: http://www.hvsistemas.com



From Arnold.Tibus at gmx.de  Tue Oct  7 13:16:12 2008
From: Arnold.Tibus at gmx.de (Arnold Tibus)
Date: Tue, 07 Oct 2008 19:16:12 +0200
Subject: [time-nuts] Where can I find a master list of NT	P /time services RFCºs?
In-Reply-To: <4fdb424f0810070725y445adc3asba2eaf93a5257ffb@mail.gmail.com>
Message-ID: <mailman.16.1223399890.2202.time-nuts@febo.com>

Gretchen,
I found a list of alternative european time servers:
http://www.novak.it/?p=71
(descr. in german)
Useful?
have fun,
Arnold


On Tue, 7 Oct 2008 10:25:04 -0400, Gretchen Baxter wrote:

>Hi,

>Where can I find a master list of NTP /time services RFC's?

>Thanx!
>_______________________________________________
>time-nuts mailing list -- time-nuts at febo.com
>To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>and follow the instructions there.





From david.partridge at dsl.pipex.com  Tue Oct  7 13:21:40 2008
From: david.partridge at dsl.pipex.com (David C. Partridge)
Date: Tue, 7 Oct 2008 18:21:40 +0100
Subject: [time-nuts] Paging Jim Robbins
Message-ID: <094DA3C5B55D4829962BE51DA2B7383E@APOLLO>

Jim,

Did you get my emails about non-delivery ...

Regards,
David Partridge



From uno at staver.se  Tue Oct  7 23:09:32 2008
From: uno at staver.se (Uno Staver)
Date: Wed, 8 Oct 2008 05:09:32 +0200
Subject: [time-nuts] viewing the upcoming leapsecond with XDaliClock
References: <mailman.3578.1215668922.2318.time-nuts@febo.com>
	<20080710061552.GA34986@mail.johnea.net>
Message-ID: <7EC11606D5624E8FAB11B6D6DA963062@gx>

Hello!

I am sorry that I cannot give you any help. Instead I have a question to 
you:

How and where did you get to know about the "leapsecond.dat" file?

     I ask you this question because before the previous leap second, 
January 1, 2006, I had a set-up similar to yours. I did not use or know 
about any "leapsecond.dat" file - that seems to be the reason why the clock 
in my computer was off by about (I am not sure today) 33 seconds when I used 
the ".../right/..." time zoneinfo file. As far as I remember, the clock 
_did_ show seconds 58, 59, 60, 00, 01 (but was off by half a minute).
     I tested this in advance, like you have done, but I could not test it 
at the actual event: because of social reasons, I had to spend the time at a 
New Year party :-)

     I tried to get more help from our time researchers, but they simply 
recommended that we turn off our Linux-based NTP servers a short time before 
the leap second, and then turn them on afterwards. That way, they would get 
the correct time initialisation from the Motorola Oncore GPS receiver, and 
the seconds would be in 'exact' phase because they are created by 1-PPS 
signals from four rubidium clocks and a cesium clock which were on 
continuously.
     Such a solution works, of course, but I would like to have a proper 
leap second handling in the kernel and the ntp protocol.
     Later, I had a discussion with a specialist at a university about 
paying him for an investigation of how the ntp and Linux kernel handle leap 
seconds, but that work was never initialised.
     There was also a discussion about the Linux kernel, ntp and leap 
seconds in the Linux kernel mailing list, but as far as I remember, there 
were radically diverging opinions on how these things should work together. 
I have not followed the kernel mailing list since then.

Regards
Uno



----- Original Message ----- 
From: <time at johnea.net>
To: <time-nuts at febo.com>
Sent: Thursday, July 10, 2008 8:15 AM
Subject: [time-nuts] viewing the upcoming leapsecond with XDaliClock


> Hello to everyone,
>
> I'm new to the list and would like to ask about displaying the upcoming
> leap second on a linux workstation.
>
> I use a PC running linux 2.6.24 and the djb clockspeed daemon periodically
> synchronized with a couple of different NTP servers. I usually have a
> correct reading within ~10ms (I know, it's not atomic time 8-)
>
> I also use the "right/America/Los_Angeles" time zoneinfo file for correct
> synchronization with TAI, and installed the new leapsecond.dat file for
> 2008 in /etc. (and I restarted clockspeed)
>
> I'm on the pacific coast of the US and as such the leapsecond occurs here
> just before 4pm.
>
> I've used the date command to set the time of my computer to Dec 31 2008
> 15:58 PDT and watched as the hour rolled over: No LeapSecond!
>
> It goes from 15:59:59 to 16:00:00
>
> I've been using XDaliClock as the display, which uses the unix localtime()
> call to retrieve the time from the system.
>
> I've done quite a bit of scroogling in an attempt to determine how the 
> time
> is kept in the kernel and how it makes it's way through to userspace for
> applications like date and xdaliclock to access. I didn't determine 8-(
>
> Can anyone advise me as to the feasibility of using this configuration to
> display the leapsecond to a crowd of eager viewers at the end of this 
> year?
>
> Thank you so much for your consideration of my noobish question, and for
> maintaining an active interest in something just because you like it!
>
> ciao bella...
>
> johnea
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 



From jherrero at hvsistemas.es  Wed Oct  8 06:28:28 2008
From: jherrero at hvsistemas.es (Javier Herrero)
Date: Wed, 08 Oct 2008 12:28:28 +0200
Subject: [time-nuts] NTP, Oncore and Allan deviation
In-Reply-To: <7EC11606D5624E8FAB11B6D6DA963062@gx>
References: <mailman.3578.1215668922.2318.time-nuts@febo.com>	<20080710061552.GA34986@mail.johnea.net>
	<7EC11606D5624E8FAB11B6D6DA963062@gx>
Message-ID: <48EC8B4C.4030302@hvsistemas.es>

Hello all,

I'm playing around with an NTP server using a Blackfin processor and 
uClinux, and a Oncore M12M-Timing. The board is our H8606, 
http://www.hvsistemas.com/en/prod/H8606.html , with the standard crystal 
oscillator replaced with a FOX924B TCXO, 
http://www.foxonline.com/pdfs/fox924.pdf . I've modified the kernel to 
support PPS from the Oncore, with timestamping done through the 
processor NMI and the cycles registers, yielding a 2.5ns resolution, and 
the preliminary observed jitter in the timestamping seems better than 
?25ns (previous to applying Oncore sawtooth correction). So until now, 
it seems quite good :).

I was thinking if the Allan intercept parameter of the ntp daemon could 
be optimized for this situation, since it has a default of 1500s that I 
suppose that is the adequate value for general usage (synchronization of 
a rather crappy computer oscillator from a WAN with quite spaced 
pollings and relatively high delays), and I presume that could be 
reduced for this system. Any thoughs would be appreciated :)

Best regards,

Javier

-- 
------------------------------------------------------------------------
Javier Herrero                            EMAIL: jherrero at hvsistemas.com
HV Sistemas S.L.                          PHONE:         +34 949 336 806
Los Charcones, 17A                        FAX:           +34 949 336 792
19170 El Casar - Guadalajara - Spain      WEB: http://www.hvsistemas.com



From sar10538 at gmail.com  Wed Oct  8 06:40:10 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Wed, 8 Oct 2008 23:40:10 +1300
Subject: [time-nuts] Mains and TV 50Hz
In-Reply-To: <BE50C3A72EBA61449C804B2C8B4AE381D05951@NEPTUNE.rakon.net>
References: <mailman.301.1223255245.2205.time-nuts@febo.com>
	<BE50C3A72EBA61449C804B2C8B4AE381D05951@NEPTUNE.rakon.net>
Message-ID: <1231b6a80810080340l606c6a2aj2e68cdc7a6d340f@mail.gmail.com>

Murray,

Having somewhat started this topic, I'd like to say thank you for this
interesting post. Indeed, I believe that it is probably possible to
gain some form of freq standard from the mains, although it would have
to be over a long term period and it does not appear that there is any
statutory requirement to keep the frequency tight enough to be of any
real practical use. On the other hand, your observations on the field
freq accuracy of TVNZ looks like a possible candidate for this.

This could be sampled on one channel of a sound card with the suitably
divided signal under test fed to the other card and it should be
fairly easy to determine the freq with a good deal of accuracy within
a relatively short period of time. The hardware for this would be
fairly simple to build and possibly give results accurate to a GPS
stabilised freq counter.

73
Steve - ZL3TUV

2008/10/6 Murray Greenman <Murray.Greenman at rakon.com>:
> Hal and others,
>
> I am sure that if one could accumulate mains cycles long enough, a
> reasonable level of accuracy could be obtained, but you need to ask
> yourself (1) to what standard is this 'reference' traceable, and (2)
> what happens if there is a power failure?
>
> On this latter point, let's say that a clock driven by the mains is
> correct to within 10 seconds/day (about 1e-4), but in the longer term
> accuracy is improved. To reach even 1ppm level, you need to accumulate
> time for 100 days. What chance is there of accumulating for 100 days
> without a power failure?
>
> About the TV system, in New Zealand (and no doubt other countries using
> the PAL standard) the field frequency is specified to be 50Hz (frame
> frequency 25Hz). Unlike NTSC, everything except the colour burst
> frequency (4433618.75Hz) can be derived directly from 1MHz by binary
> division, which is really handy.
>
> Whether the transmitted frequency is accurately 50Hz depends on the
> network. Some of them are quite poor (i.e. worse than 1ppm), but I know
> that TVNZ operate their North Island network from a Trimble Thunderbolt
> in each studio, which controls a digital mixing desk. While there is
> delay managed within the network, the transmitted line and frame
> frequency is constant and also related to the GPS second. For many years
> the government labs in Wellington measured and published monthly figures
> of the error in the TV reference.
>
> Perversely, some of the smaller networks have highly accurate vision
> carrier frequencies (allows for channel reuse), but poorly controlled
> sync!
>
> Regards,
> Murray ZL1BPU
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>



-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From df6jb at ulrich-bangert.de  Wed Oct  8 10:10:22 2008
From: df6jb at ulrich-bangert.de (Ulrich Bangert)
Date: Wed, 8 Oct 2008 16:10:22 +0200
Subject: [time-nuts] What is the best counter for a Time Nuts?
Message-ID: <06B2020E21E7485BAE78A7667DB7CA7B@athlon>

Gentlemen,

up to now I have been thinking that I am pretty well informed about
current counter technology but some experiences of the last days make me
doubt. The following applies to frequency measurements of a 10 MHz
signal.

I have received some data measured with an Agilent 53131 counter from
Time Nuts member James Miller. That data shows a resolution of 3 digits
after the decimal point for a frequency measurement of 1 s "Gate time"
and 4 digits for a 10 s "Gate time". 

This is perfectly in line with what I thought to know about modern
counters: Internally EVERY type of measurement is reduced to a time
interval measurement. Since a frequency measurement with 1 s "Gate time"
equals a time interval measurement of an 1 s interval and the counter
has an single shot resolution of 500 ps the relative statistical error
due to this resolution is 500 ps / 1 s = 5*E-10. As the frequency is
computed from the time interval measurement is has the same relative
error and for that reason displaying 3 digits after the decimal point is
a good choice because 0.001 Hz (1E-10) is the least digit of
significance. Using a digit more would suggest a resolution that is not
available, using one digit less would decrease the numerical resolution
below the measurement resolution. 

Up to this point my statement of beliefs is in harmony with Agilent.

Now comes the strange part: In the course of a discussion between Time
Nuts member Bernd Neubig of AXTAL Germany and me I received data
measured with an Agilent 53132 which is the 53131's big brother with a
better single shot resolution of 150 ps. 

I have been prepared to see this better resolution in the data but what
I really have seen SHOCKED me a lot. Not only does the 53132 generate 5
(!) digits after the decimal point for a 1 s "Gate time" (with 0.00001
equal to 1E-12) a sigma tau diagram of the data revealed that the last
digit was not only "noise" but seemed to be of real significance. I had
been presuming that perhaps the counter's statistics had been enabled
for that but as it turned out this was not the case. From that data one
must make the conclusion that the overall jitter of the 53132 including
the resolution quantification, trigger errors and everything else is
<=5E-12 !!!!!!

Big question: If the single shot resolution is only 3-4 times better
that that of the 53131 and much inferior to the 20 ps of my SR620, how
does the 53132 manage to be THAT GOOD A PERFORMER? Magic? Black art? 

I immediatly made the same measurement with my SR620 to receive a
counter noise floor of 6E-11 for 1 s frequency data, pretty much a
decade worse of the 53132. Must we throw our 5370s and SR620s out of the
window and settle for second hand  53132 from eBay to make precise
stability measurements ???

TIA for your suggestions    

Ulrich Bangert
www.ulrich-bangert.de
Ortholzer Weg 1
27243 Gross Ippener 



From magnus at rubidium.dyndns.org  Wed Oct  8 11:20:29 2008
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Wed, 8 Oct 2008 17:20:29 +0200 (CEST)
Subject: [time-nuts] What is the best counter for a Time Nuts?
In-Reply-To: <06B2020E21E7485BAE78A7667DB7CA7B@athlon>
References: <06B2020E21E7485BAE78A7667DB7CA7B@athlon>
Message-ID: <c4615bf3b2f632e7d1fbe186bb7288cd.squirrel@rubidium.dyndns.org>

Ulrich,

> up to now I have been thinking that I am pretty well informed about
> current counter technology but some experiences of the last days make me
> doubt. The following applies to frequency measurements of a 10 MHz
> signal.
>
> I have received some data measured with an Agilent 53131 counter from
> Time Nuts member James Miller. That data shows a resolution of 3 digits
> after the decimal point for a frequency measurement of 1 s "Gate time"
> and 4 digits for a 10 s "Gate time".
>
> This is perfectly in line with what I thought to know about modern
> counters: Internally EVERY type of measurement is reduced to a time
> interval measurement.

To a reciprocal counter base measurement. For an insight in what
calculations is performed to shape results, see the HP 5372A programmers
manual which discloses a lot of details.

> Since a frequency measurement with 1 s "Gate time"
> equals a time interval measurement of an 1 s interval and the counter
> has an single shot resolution of 500 ps the relative statistical error
> due to this resolution is 500 ps / 1 s = 5*E-10.

Actually you need to multiply by two since both the start and stop channel
has independent errors. If you look in the 53131A/132A manual you see

RMS resolution = sqrt(t_RES^2 + Start Trigger Error^2 + Stop Trigger Error^2)

                 53131A  53132A
Trigger Error    500 ps  150 ps
t_RES            750 ps  300 ps

There is further details in the operational manual (chapter 3: Measurement
Specification).

> As the frequency is
> computed from the time interval measurement is has the same relative
> error and for that reason displaying 3 digits after the decimal point is
> a good choice because 0.001 Hz (1E-10) is the least digit of
> significance. Using a digit more would suggest a resolution that is not
> available, using one digit less would decrease the numerical resolution
> below the measurement resolution.
>
> Up to this point my statement of beliefs is in harmony with Agilent.

Certainly, and it matches the graphs in their manual very well.

> Now comes the strange part: In the course of a discussion between Time
> Nuts member Bernd Neubig of AXTAL Germany and me I received data
> measured with an Agilent 53132 which is the 53131's big brother with a
> better single shot resolution of 150 ps.
>
> I have been prepared to see this better resolution in the data but what
> I really have seen SHOCKED me a lot. Not only does the 53132 generate 5
> (!) digits after the decimal point for a 1 s "Gate time" (with 0.00001
> equal to 1E-12) a sigma tau diagram of the data revealed that the last
> digit was not only "noise" but seemed to be of real significance. I had
> been presuming that perhaps the counter's statistics had been enabled
> for that but as it turned out this was not the case. From that data one
> must make the conclusion that the overall jitter of the 53132 including
> the resolution quantification, trigger errors and everything else is
> <=5E-12 !!!!!!
>
> Big question: If the single shot resolution is only 3-4 times better
> that that of the 53131 and much inferior to the 20 ps of my SR620, how
> does the 53132 manage to be THAT GOOD A PERFORMER? Magic? Black art?
>
> I immediatly made the same measurement with my SR620 to receive a
> counter noise floor of 6E-11 for 1 s frequency data, pretty much a
> decade worse of the 53132. Must we throw our 5370s and SR620s out of the
> window and settle for second hand  53132 from eBay to make precise
> stability measurements ???

No. I think you are seeing the result of the 53132A gliding window
averager. There are articles that details this estimator and basically
cuts it into small pieces for use in Allan deviation measures.

You are right in not believing your eyes.

I have a 53132A at work and a SR-620 at home. I could compare them to
verify your measurements. 10 MHz sources are plentiful.

What you really should do is to take a number of raw TI difference
measures and calculate the Allan deviation plots for both counters. I
think you will find that they will match the 500 ps and 150 ps curves will
match better.

Notice that the timing jitter changes from 50 ps to 3 ps between the models.

I can dig up more details as I get home if you don't get enought here and
from fellow time-nuts.

The short story is: Do NOT estimate expected Allan deviation noisefloors
from the (display) readings of your counter. There exist several
"resolution improvement" algorithms. These are to our benefit when using
the counter as a frequency or period estimator as we can get result
quicker, but these improvements does not ripple over to the Allan
deviation plots.

Cheers,
Magnus


From hmurray at megapathdsl.net  Wed Oct  8 16:17:57 2008
From: hmurray at megapathdsl.net (Hal Murray)
Date: Wed, 08 Oct 2008 13:17:57 -0700
Subject: [time-nuts] Mains and TV 50Hz
In-Reply-To: Message from "Murray Greenman" <Murray.Greenman@rakon.com> 
	of "Mon, 06 Oct 2008 15:27:28 +1300."
	<BE50C3A72EBA61449C804B2C8B4AE381D05951@NEPTUNE.rakon.net> 
Message-ID: <20081008201758.EBC98BCD5@ip-64-139-1-69.sjc.megapath.net>

> On this latter point, let's say that a clock driven by the mains is
> correct to within 10 seconds/day (about 1e-4), but in the longer term
> accuracy is improved. To reach even 1ppm level, you need to accumulate
> time for 100 days. What chance is there of accumulating for 100 days
> without a power failure? 

There are other issues besides power.

  Will your OS stay up that long?
  How many other things are you running on that box?
  Will you get impatient with the software?
  Will you need to rearrange that corner of your lab?

I've got one box that's been up for 50 days since my last power failure.  I'm 
pretty sure I could keep it up for a long time as long as I didn't want to do 
much else on it.

That last power problem was out for several hours.  Most of my problems are 
minor glitches.  A UPS could easily ride over them.

I think the interesting problem area would be filtering the input signal.  
Mechanical clocks have a flywheel.  We'd need an analog filter on the front 
end and/or a software filter.

What's the Q of a typical mains powered clock?  What is the Q of a (small) 
motor/generator set with a big flywheel?

Does anybody have any scope traces of a typical power glitch?  How many 
cycles get trashed?  What's the typical duration?  Does the phase of the 
before-glitch signal match well with the phase of the after-glitch signal?



-- 
These are my opinions, not necessarily my employer's.  I hate spam.





From bruce.griffiths at xtra.co.nz  Wed Oct  8 16:34:28 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Thu, 09 Oct 2008 09:34:28 +1300
Subject: [time-nuts] What is the best counter for a Time Nuts?
In-Reply-To: <06B2020E21E7485BAE78A7667DB7CA7B@athlon>
References: <06B2020E21E7485BAE78A7667DB7CA7B@athlon>
Message-ID: <48ED1954.2040906@xtra.co.nz>

Ulrich Bangert wrote:
> Gentlemen,
>
> up to now I have been thinking that I am pretty well informed about
> current counter technology but some experiences of the last days make me
> doubt. The following applies to frequency measurements of a 10 MHz
> signal.
>
> I have received some data measured with an Agilent 53131 counter from
> Time Nuts member James Miller. That data shows a resolution of 3 digits
> after the decimal point for a frequency measurement of 1 s "Gate time"
> and 4 digits for a 10 s "Gate time". 
>
> This is perfectly in line with what I thought to know about modern
> counters: Internally EVERY type of measurement is reduced to a time
> interval measurement. Since a frequency measurement with 1 s "Gate time"
> equals a time interval measurement of an 1 s interval and the counter
> has an single shot resolution of 500 ps the relative statistical error
> due to this resolution is 500 ps / 1 s = 5*E-10. As the frequency is
> computed from the time interval measurement is has the same relative
> error and for that reason displaying 3 digits after the decimal point is
> a good choice because 0.001 Hz (1E-10) is the least digit of
> significance. Using a digit more would suggest a resolution that is not
> available, using one digit less would decrease the numerical resolution
> below the measurement resolution. 
>
> Up to this point my statement of beliefs is in harmony with Agilent.
>
> Now comes the strange part: In the course of a discussion between Time
> Nuts member Bernd Neubig of AXTAL Germany and me I received data
> measured with an Agilent 53132 which is the 53131's big brother with a
> better single shot resolution of 150 ps. 
>
> I have been prepared to see this better resolution in the data but what
> I really have seen SHOCKED me a lot. Not only does the 53132 generate 5
> (!) digits after the decimal point for a 1 s "Gate time" (with 0.00001
> equal to 1E-12) a sigma tau diagram of the data revealed that the last
> digit was not only "noise" but seemed to be of real significance. I had
> been presuming that perhaps the counter's statistics had been enabled
> for that but as it turned out this was not the case. From that data one
> must make the conclusion that the overall jitter of the 53132 including
> the resolution quantification, trigger errors and everything else is
> <=5E-12 !!!!!!
>
> Big question: If the single shot resolution is only 3-4 times better
> that that of the 53131 and much inferior to the 20 ps of my SR620, how
> does the 53132 manage to be THAT GOOD A PERFORMER? Magic? Black art? 
>
> I immediatly made the same measurement with my SR620 to receive a
> counter noise floor of 6E-11 for 1 s frequency data, pretty much a
> decade worse of the 53132. Must we throw our 5370s and SR620s out of the
> window and settle for second hand  53132 from eBay to make precise
> stability measurements ???
>
> TIA for your suggestions    
>
> Ulrich Bangert
> www.ulrich-bangert.de
> Ortholzer Weg 1
> 27243 Gross Ippener 
>
>
>   
Ulrich

These effectively counters time stamp every Nth signal zero crossing and 
then fit a linear regression line to the results.
This reduces the effective noise contribution from the interpolator.
Since the noise transfer function is thereby altered over that of a 
conventional counter or reciprocal counter one cannot use the results to 
compute the Allen deviation directly.

Read the papers on the Pendulum site for further details.

http://www.pendulum-instruments.com/Assets/download/frequency_counting_article.pdf

http://www.pendulum-instruments.com/Assets/download/timestamping_article.pdf

Enrico Rubiola published a paper on the effect of using the output from 
such counters in that Allen deviation calculations.

http://arxiv.org/abs/physics?papernum=0411227

A recent Australian paper purports to correct some of the errors in 
Enrico's paper, but the basic conclusion is the same one cannot 
calculate the Allen deviation directly from measurements obtained with 
such a counter.


Bruce


From tvb at LeapSecond.com  Wed Oct  8 16:34:47 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Wed, 8 Oct 2008 13:34:47 -0700
Subject: [time-nuts] What is the best counter for a Time Nuts?
References: <06B2020E21E7485BAE78A7667DB7CA7B@athlon>
Message-ID: <000401c92985$4ec3e520$2801a8c0@pc52>

> Big question: If the single shot resolution is only 3-4 times better
> that that of the 53131 and much inferior to the 20 ps of my SR620, how
> does the 53132 manage to be THAT GOOD A PERFORMER? Magic? Black art? 

Hi Ulrich,

My understanding is that 1) the 53132A has a single-shot
resolution of about 150 ps, but also 2) it can do something like
200,000 phase measurement per second for CW RF inputs.

In frequency mode, the frequency computed and displayed
each second is the result of internal statistics on those
200,000 samples, which in general is much better than two
single TI measurements made 1 second apart.

In the best case of no correlation between input and timebase
the frequency resolution would be 150 ps / sqrt(200 000), which
is sub-ps.

In reality, depending on the numerical character of the input RF
frequency, you don't get the full sqrt(200000) factor. Page 3-13
of the 53132A user manual tries to explain this. But for most
input frequencies it is in the low picoseconds, which is why it
can be called a 12-digit per second counter. Google for
53132a user manual for a copy of the manual.

(As an aside, if you use a 53132A on a slowly warming OCXO
you can see the display resolution change when the magic n/m
threshold, mentioned in the back of the manual, is crossed).

The bottom line is that the SR 620 or hp 5370 is a better counter
for TI (single-shot) measurements (e.g., comparing 1 PPS ticks).
But for CW frequency measurements, the 53132A is much quicker
due to this extreme internal oversampling. To be fair, I'm pretty
sure that other modern counters (e.g., Philips, Pendulum) also
use this frequency resolution trick.

/tvb




From bruce.griffiths at xtra.co.nz  Wed Oct  8 17:02:44 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Thu, 09 Oct 2008 10:02:44 +1300
Subject: [time-nuts] What is the best counter for a Time Nuts?
In-Reply-To: <000401c92985$4ec3e520$2801a8c0@pc52>
References: <06B2020E21E7485BAE78A7667DB7CA7B@athlon>
	<000401c92985$4ec3e520$2801a8c0@pc52>
Message-ID: <48ED1FF4.5020803@xtra.co.nz>

Tom Van Baak wrote:
>> Big question: If the single shot resolution is only 3-4 times better
>> that that of the 53131 and much inferior to the 20 ps of my SR620, how
>> does the 53132 manage to be THAT GOOD A PERFORMER? Magic? Black art? 
>>     
>
> Hi Ulrich,
>
> My understanding is that 1) the 53132A has a single-shot
> resolution of about 150 ps, but also 2) it can do something like
> 200,000 phase measurement per second for CW RF inputs.
>
> In frequency mode, the frequency computed and displayed
> each second is the result of internal statistics on those
> 200,000 samples, which in general is much better than two
> single TI measurements made 1 second apart.
>
> In the best case of no correlation between input and timebase
> the frequency resolution would be 150 ps / sqrt(200 000), which
> is sub-ps.
>
> In reality, depending on the numerical character of the input RF
> frequency, you don't get the full sqrt(200000) factor. Page 3-13
> of the 53132A user manual tries to explain this. But for most
> input frequencies it is in the low picoseconds, which is why it
> can be called a 12-digit per second counter. Google for
> 53132a user manual for a copy of the manual.
>
> (As an aside, if you use a 53132A on a slowly warming OCXO
> you can see the display resolution change when the magic n/m
> threshold, mentioned in the back of the manual, is crossed).
>
> The bottom line is that the SR 620 or hp 5370 is a better counter
> for TI (single-shot) measurements (e.g., comparing 1 PPS ticks).
> But for CW frequency measurements, the 53132A is much quicker
> due to this extreme internal oversampling. To be fair, I'm pretty
> sure that other modern counters (e.g., Philips, Pendulum) also
> use this frequency resolution trick.
>
> /tvb
>
>   
The Australian IEEE paper details are:

/Considerations on the Measurement of the Stability of Oscillators with 
Frequency Counters, /Samuel T. Dawkins, John J. McFerran, Andre N Luiten.

All authors are from the School of Physics, university of Western Australia.

Bruce


From bruce.griffiths at xtra.co.nz  Wed Oct  8 17:25:14 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Thu, 09 Oct 2008 10:25:14 +1300
Subject: [time-nuts] What is the best counter for a Time Nuts?
In-Reply-To: <000401c92985$4ec3e520$2801a8c0@pc52>
References: <06B2020E21E7485BAE78A7667DB7CA7B@athlon>
	<000401c92985$4ec3e520$2801a8c0@pc52>
Message-ID: <48ED253A.3070905@xtra.co.nz>

Tom Van Baak wrote:
> Hi Ulrich,
>
> My understanding is that 1) the 53132A has a single-shot
> resolution of about 150 ps, but also 2) it can do something like
> 200,000 phase measurement per second for CW RF inputs.
>
> In frequency mode, the frequency computed and displayed
> each second is the result of internal statistics on those
> 200,000 samples, which in general is much better than two
> single TI measurements made 1 second apart.
>
> In the best case of no correlation between input and timebase
> the frequency resolution would be 150 ps / sqrt(200 000), which
> is sub-ps.
>
> In reality, depending on the numerical character of the input RF
> frequency, you don't get the full sqrt(200000) factor. Page 3-13
> of the 53132A user manual tries to explain this. But for most
> input frequencies it is in the low picoseconds, which is why it
> can be called a 12-digit per second counter. Google for
> 53132a user manual for a copy of the manual.
>
>   
It is feasible to achieve a somewhat higher timestamp resolution (~20ps) 
and continuous sampling rate (> 1.5MSPS) than those of the 53132A 
relatively inexpensively provided that a DSP or similar processor is 
used to process the time stamp  data in real time.

It is also possible to use a SR620 or a 5370 to take 1000 timestamps/sec.
However may require using some external hardware (frequency divider).
For maximum accuracy and precision the resultant data has to be logged 
and processed off line using a PC or other computer.

> (As an aside, if you use a 53132A on a slowly warming OCXO
> you can see the display resolution change when the magic n/m
> threshold, mentioned in the back of the manual, is crossed).
>
> The bottom line is that the SR 620 or hp 5370 is a better counter
> for TI (single-shot) measurements (e.g., comparing 1 PPS ticks).
> But for CW frequency measurements, the 53132A is much quicker
> due to this extreme internal oversampling. To be fair, I'm pretty
> sure that other modern counters (e.g., Philips, Pendulum) also
> use this frequency resolution trick.
>
> /tvb
>   
Some Pendulum (A Philips spinoff) and Fluke (rebadged Pendulum) counters 
do use an improved (fit linear regression line to time sequence) 
statistical technique.

Bruce


From brooke at pacific.net  Wed Oct  8 17:43:07 2008
From: brooke at pacific.net (Brooke Clarke)
Date: Wed, 08 Oct 2008 14:43:07 -0700
Subject: [time-nuts] What is the best counter for a Time Nuts?
In-Reply-To: <48ED253A.3070905@xtra.co.nz>
References: <06B2020E21E7485BAE78A7667DB7CA7B@athlon>	<000401c92985$4ec3e520$2801a8c0@pc52>
	<48ED253A.3070905@xtra.co.nz>
Message-ID: <48ED296B.7090906@pacific.net>

Hi Bruce:

The Ref Output on the front panel of the SR620 is derived (1/10,000) from the 
EXT IN on the rear panel.  So when you apply a 10 MHz signal to EXT IN you get 
a 1 kHz REF OUT.  Appendix B in the PSR10 Rubidium source manual describes how 
to use this along with the arming function to average 1,000 measurements per 
second resulting in 2E-12 per second on the display.  i.e. very close to the 
HP53132A.  So no external hardware is required and no PC to get this result.

Have Fun,

Brooke Clarke
http://www.prc68.com
http://www.precisionclock.com


Bruce Griffiths wrote:
.....
> 
> It is also possible to use a SR620 or a 5370 to take 1000 timestamps/sec.
> However may require using some external hardware (frequency divider).
> For maximum accuracy and precision the resultant data has to be logged 
> and processed off line using a PC or other computer.
> 



From rdarlington at gmail.com  Wed Oct  8 18:11:27 2008
From: rdarlington at gmail.com (Robert Darlington)
Date: Wed, 8 Oct 2008 16:11:27 -0600
Subject: [time-nuts] Looking for a Efratom FRS-C connector
Message-ID: <b3bd5fcb0810081511w7af284fke11e4ff0cec6402c@mail.gmail.com>

Hello all,

Would any of you happen to know where I can find a mating connector for the
Efratom FRS-C rubidium standard?  I see one eBay ad via a Google search
listing it as a "Cannon P/N DAM11WIS", but searches on the ITT/Cannon
website don't turn up any hits.    Is this a valid part number?

Thank you,
Bob, N3XKB

From brooke at pacific.net  Wed Oct  8 18:22:26 2008
From: brooke at pacific.net (Brooke Clarke)
Date: Wed, 08 Oct 2008 15:22:26 -0700
Subject: [time-nuts] Looking for a Efratom FRS-C connector
In-Reply-To: <b3bd5fcb0810081511w7af284fke11e4ff0cec6402c@mail.gmail.com>
References: <b3bd5fcb0810081511w7af284fke11e4ff0cec6402c@mail.gmail.com>
Message-ID: <48ED32A2.6020600@pacific.net>

Hi Bob:

I think you have almost the correct part.
The Stanford Research PRS10 uses the same connector, see:
http://www.prc68.com/I/PRS10.shtml

The ITT Cannon web page shows many stocking distys for it and the coax insert:
http://www.ittcannon.com/support/stockcheck_result.asp

Have Fun,

Brooke Clarke, N6GCE
http://www.prc68.com/P/Prod.html  Products I make and sell
http://www.prc68.com/Alpha.shtml  All my web pages listed based on html name
http://www.PRC68.com
http://www.precisionclock.com
http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Web Cam

Robert Darlington wrote:
> Hello all,
> 
> Would any of you happen to know where I can find a mating connector for the
> Efratom FRS-C rubidium standard?  I see one eBay ad via a Google search
> listing it as a "Cannon P/N DAM11WIS", but searches on the ITT/Cannon
> website don't turn up any hits.    Is this a valid part number?
> 
> Thank you,
> Bob, N3XKB
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 


From jherrero at hvsistemas.es  Wed Oct  8 18:34:13 2008
From: jherrero at hvsistemas.es (Javier Herrero)
Date: Thu, 09 Oct 2008 00:34:13 +0200
Subject: [time-nuts] Looking for a Efratom FRS-C connector
In-Reply-To: <b3bd5fcb0810081511w7af284fke11e4ff0cec6402c@mail.gmail.com>
References: <b3bd5fcb0810081511w7af284fke11e4ff0cec6402c@mail.gmail.com>
Message-ID: <48ED3565.7010102@hvsistemas.es>

The part number is 11W1S (one instead of letter i). Mouser has several 
connectors with 11W1 contact arrangement, and surely that some are 
adequate for the FRS-C. Try exploring this link:

http://www.mouser.com/Search/Refine.aspx?FS=TRUE&Ntt=*11w*&Ne=3977227+1447464&N=3977227+1323038&Ntx=mode%2bmatchall&Ns=P_SField&OriginalKeyword=11w&Ntk=Mouser_Wildcards

Regards,

Javier

Robert Darlington escribi?:
> Hello all,
>
> Would any of you happen to know where I can find a mating connector for the
> Efratom FRS-C rubidium standard?  I see one eBay ad via a Google search
> listing it as a "Cannon P/N DAM11WIS", but searches on the ITT/Cannon
> website don't turn up any hits.    Is this a valid part number?
>
> Thank you,
> Bob, N3XKB
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>

-- 
------------------------------------------------------------------------
Javier Herrero                            EMAIL: jherrero at hvsistemas.com
HV Sistemas S.L.                          PHONE:         +34 949 336 806
Los Charcones, 17A                        FAX:           +34 949 336 792
19170 El Casar - Guadalajara - Spain      WEB: http://www.hvsistemas.com



From rdarlington at gmail.com  Wed Oct  8 18:36:47 2008
From: rdarlington at gmail.com (Robert Darlington)
Date: Wed, 8 Oct 2008 16:36:47 -0600
Subject: [time-nuts] Efratom FRS-C connector (found!)
Message-ID: <b3bd5fcb0810081536l2bf798aco639133fa7b8a0d58@mail.gmail.com>

Sorry, I guess I'm having one of those days.  I managed to find it with a
partial part number search.  The correct (as far as I can tell) part number
is DAM11W1S, and Newark part number 14C7745.  They're going for $4.20 each
but don't know for sure if it comes with pins!

-Bob

From bill at iaxs.net  Wed Oct  8 18:52:59 2008
From: bill at iaxs.net (Bill Hawkins)
Date: Wed, 8 Oct 2008 17:52:59 -0500
Subject: [time-nuts] Mains and TV 50Hz
In-Reply-To: <20081008201758.EBC98BCD5@ip-64-139-1-69.sjc.megapath.net>
References: Message from "Murray Greenman" <Murray.Greenman@rakon.com> of "Mon,
	06 Oct 2008 15:27:28
	+1300."<BE50C3A72EBA61449C804B2C8B4AE381D05951@NEPTUNE.rakon.net>
	<20081008201758.EBC98BCD5@ip-64-139-1-69.sjc.megapath.net>
Message-ID: <8B603F6318C9465188C1743B816C1AF1@cyrus>

High voltage power lines subject to lightning strikes have reclosing
breakers that allow the fault arc to extinguish before reclosing.
Last I knew (1968) the reclosing delay was 30 cycles or 1/2 second.

Since the breaker recloses into a system of thousands of generators,
there is no phase change, except from the damped oscillation in the
distribution network when the breaker recloses. Breakers are probably
designed to reclose at the zero volt crossing, approximately.

It's not correct to say that the daily error can be 10 seconds. You
may find that much error over part of the day, but power dispatchers,
who direct the production of the power plants, work all night to
bring the lost cycles back so that the 6 AM (or so) error is less than
a second.

See http://clockhistory.com/telechron/ for the early days of power
frequency regulation. Now central dispatch stations compare an
electronic cycle-counting clock against GPS time (or WWV) and
manually adjust the steam rates at different plants, perhaps with
a phone call.

How did the cycles get lost? Demand is not completely predictable.
Higher demand than available steam causes the generators to slow
down. The time constant of the system is too long to allow close
control of generator speed. Individual control is not possible in
an integrated synchronous system. HV DC tie lines are used to
isolate major systems. There were four in the US 20 years ago.

What you could do is get to the oscillator of a UPS and phase lock it
to the power line, holding the comparator output when there is no
line power.

Bill Hawkins

I love spam. It reminds me that there are people dumber than me,
so I'm not so bad.


-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Hal Murray
Sent: Wednesday, October 08, 2008 3:18 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Mains and TV 50Hz

> On this latter point, let's say that a clock driven by the mains is 
> correct to within 10 seconds/day (about 1e-4), but in the longer term 
> accuracy is improved. To reach even 1ppm level, you need to accumulate

> time for 100 days. What chance is there of accumulating for 100 days 
> without a power failure?

There are other issues besides power.

  Will your OS stay up that long?
  How many other things are you running on that box?
  Will you get impatient with the software?
  Will you need to rearrange that corner of your lab?

I've got one box that's been up for 50 days since my last power failure.
I'm pretty sure I could keep it up for a long time as long as I didn't
want to do much else on it.

That last power problem was out for several hours.  Most of my problems
are minor glitches.  A UPS could easily ride over them.

I think the interesting problem area would be filtering the input
signal.  
Mechanical clocks have a flywheel.  We'd need an analog filter on the
front end and/or a software filter.

What's the Q of a typical mains powered clock?  What is the Q of a
(small) motor/generator set with a big flywheel?

Does anybody have any scope traces of a typical power glitch?  How many
cycles get trashed?  What's the typical duration?  Does the phase of the
before-glitch signal match well with the phase of the after-glitch
signal?

--
These are my opinions, not necessarily my employer's.  I hate spam.




From mikes at flatsurface.com  Wed Oct  8 18:42:00 2008
From: mikes at flatsurface.com (Mike S)
Date: Wed, 08 Oct 2008 18:42:00 -0400
Subject: [time-nuts] Looking for a Efratom FRS-C connector
In-Reply-To: <b3bd5fcb0810081511w7af284fke11e4ff0cec6402c@mail.gmail.com
 >
References: <b3bd5fcb0810081511w7af284fke11e4ff0cec6402c@mail.gmail.com>
Message-ID: <20081008224203.31A771165C3@hamburg.alientech.net>

At 06:11 PM 10/8/2008, Robert Darlington wrote...
>Hello all,
>
>Would any of you happen to know where I can find a mating connector 
>for the
>Efratom FRS-C rubidium standard?  I see one eBay ad via a Google 
>search
>listing it as a "Cannon P/N DAM11WIS", but searches on the ITT/Cannon
>website don't turn up any hits.    Is this a valid part number?

FCT makes them, and they're available from Mouser.

Here's the catalog page: http://www.mouser.com/catalog/635/1223.pdf

Mouser P/Ns: 152-FM11W1S-K121 (connector shell), 152-FMX006P102 (50 ohm 
crimp/solder coax contact for RG-174U sized cable) 



From bruce.griffiths at xtra.co.nz  Wed Oct  8 19:06:43 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Thu, 9 Oct 2008 10:06:43 +1100 (EST)
Subject: [time-nuts] Fw:  What is the best counter for a Time Nuts?
Message-ID: <792097.73637.qm@web96109.mail.aue.yahoo.com>





----- Forwarded Message ----
From: Brooke Clarke <brooke at pacific.net>
To: Discussion of precise time and frequency measurement <time-nuts at febo.com>
Sent: Thursday, 9 October, 2008 10:43:07 AM
Subject: Re: [time-nuts] What is the best counter for a Time Nuts?

Hi Bruce:

The Ref Output on the front panel of the SR620 is derived (1/10,000) from the 
EXT IN on the rear panel.  So when you apply a 10 MHz signal to EXT IN you get 
a 1 kHz REF OUT.  Appendix B in the PSR10 Rubidium source manual describes how 
to use this along with the arming function to average 1,000 measurements per 
second resulting in 2E-12 per second on the display...  i.e. very close to the 
HP53132A.  So no external hardware is required and no PC to get this result.

Have Fun,

Brooke Clarke
http://www.prc68.com
http://www.precisionclock.com


Bruce Griffiths wrote:
.....
> 
> It is also possible to use a SR620 or a 5370 to take 1000 timestamps/sec.
> However may require using some external hardware (frequency divider).
> For maximum accuracy and precision the resultant data has to be logged 
> and processed off line using a PC or other computer.
> 


_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

From bruce.griffiths at xtra.co.nz  Wed Oct  8 19:42:07 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Thu, 09 Oct 2008 12:42:07 +1300
Subject: [time-nuts] What is the best counter for a Time Nuts?
In-Reply-To: <48ED296B.7090906@pacific.net>
References: <06B2020E21E7485BAE78A7667DB7CA7B@athlon>	<000401c92985$4ec3e520$2801a8c0@pc52>	<48ED253A.3070905@xtra.co.nz>
	<48ED296B.7090906@pacific.net>
Message-ID: <48ED454F.4000404@xtra.co.nz>

Brooke Clarke wrote:
> Hi Bruce:
>
> The Ref Output on the front panel of the SR620 is derived (1/10,000) from the 
> EXT IN on the rear panel.  So when you apply a 10 MHz signal to EXT IN you get 
> a 1 kHz REF OUT.  Appendix B in the PSR10 Rubidium source manual describes how 
> to use this along with the arming function to average 1,000 measurements per 
> second resulting in 2E-12 per second on the display.  i.e. very close to the 
> HP53132A.  So no external hardware is required and no PC to get this result.
>
> Have Fun,
>   
Brooke

Now I am back on my own network, Here's is what I actually intended to post.

That only works well when averaging a fixed time interval or phase error.
In general with a frequency input, the unwrapped phase measures are 
linear in time.
You need to process the raw measurements to unwrap the phase and fit a 
linear regression line to the unwrapped phase.
You also need to divide down the frequency to produce an output 
frequency that is less than the maximum measurement transfer rate  to 
the PC.
If I remember correctly the 5370 (in binary mode) can transfer more 
measurements per second than the SR620.

So in this case the older hardware has a speed advantage although it 
needs a pair of external frequency dividers (the extra one is used to 
divide down your frequency reference to a convenient frequency for the 
STOP input greater than the divided down input frequency connected to 
the START input.).

Grenhall's picket fence algorithm can then be used to unwrap the 
measured time intervals into the corresponding time stamps.

Bruce


From bruce.griffiths at xtra.co.nz  Wed Oct  8 20:43:19 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Thu, 09 Oct 2008 13:43:19 +1300
Subject: [time-nuts] What is the best counter for a Time Nuts?
In-Reply-To: <48ED454F.4000404@xtra.co.nz>
References: <06B2020E21E7485BAE78A7667DB7CA7B@athlon>	<000401c92985$4ec3e520$2801a8c0@pc52>	<48ED253A.3070905@xtra.co.nz>	<48ED296B.7090906@pacific.net>
	<48ED454F.4000404@xtra.co.nz>
Message-ID: <48ED53A7.2000309@xtra.co.nz>

Bruce Griffiths wrote:
> Brooke Clarke wrote:
>   
>> Hi Bruce:
>>
>> The Ref Output on the front panel of the SR620 is derived (1/10,000) from the 
>> EXT IN on the rear panel.  So when you apply a 10 MHz signal to EXT IN you get 
>> a 1 kHz REF OUT.  Appendix B in the PSR10 Rubidium source manual describes how 
>> to use this along with the arming function to average 1,000 measurements per 
>> second resulting in 2E-12 per second on the display.  i.e. very close to the 
>> HP53132A.  So no external hardware is required and no PC to get this result.
>>
>> Have Fun,
>>   
>>     
> Brooke
>
> Now I am back on my own network, Here's is what I actually intended to post.
>
> That only works well when averaging a fixed time interval or phase error.
> In general with a frequency input, the unwrapped phase measures are 
> linear in time.
> You need to process the raw measurements to unwrap the phase and fit a 
> linear regression line to the unwrapped phase.
> You also need to divide down the frequency to produce an output 
> frequency that is less than the maximum measurement transfer rate  to 
> the PC.
> If I remember correctly the 5370 (in binary mode) can transfer more 
> measurements per second than the SR620.
>
> So in this case the older hardware has a speed advantage although it 
> needs a pair of external frequency dividers (the extra one is used to 
> divide down your frequency reference to a convenient frequency for the 
> STOP input greater than the divided down input frequency connected to 
> the START input.).
>
> Grenhall's picket fence algorithm can then be used to unwrap the 
> measured time intervals into the corresponding time stamps.
>
> Bruce
>
>   
Addendum:

It also can be made to work well for the case where there is only an 
occasional single phase wrap per averaging period.
This applies to the case when the 2 frequencies being compared are 
within 1Hz or so of one another as in the case discussed in the PRS10 
manual appendix.
When there are many phase wraps per averaging time it becomes 
difficult/impossible to reliably account for such phase wraps without 
access to the raw measurements.

Bruce


From jsrobbins at earthlink.net  Wed Oct  8 20:51:50 2008
From: jsrobbins at earthlink.net (James  Robbins)
Date: Wed, 8 Oct 2008 20:51:50 -0400
Subject: [time-nuts] SR620:  Cal Error 07 in Self Calibrate routine
Message-ID: <D28C2E61B8F040539CD9941A34D0086D@dell8200>

My SR620 fails to complete its Self Calibration Routine by showing "Cal
Error 07".  It won't proceed beyond that point, although at times it will
jump to Cal 13-16 programs.  Cal Error 07 is listed as flagging "hardware
problems" in the "Start TAC" (Time to Amplitude Converters) which are "the
cirsuits which perform the analog interpolation between the 90 MHz clock
tics."  Anyone have any ideas on how to track this problem down?  Also, I
have the "Manual" for this unit but can't find the "Service Manual" online.
Any help would be appreciated.  Jim Robbins

From jsrobbins at earthlink.net  Wed Oct  8 20:56:49 2008
From: jsrobbins at earthlink.net (Jim Robbins)
Date: Wed, 8 Oct 2008 20:56:49 -0400
Subject: [time-nuts] SR620 fails in Self Calibration routine 07
Message-ID: <E16CB3C0B3504DE59B9B5A17FA6EFC2C@dell8200>

My SR620 fails in its Self Calibration routine at "Cal Error 07".  The Users Manual describes this error as a problem with the "Start TAC" (Time to Amplitude Converters) and indicate that this flags a Hardware problem in the circuits which perform the analog interpolation between the 90 MHz clock ticks.  Anyone have any experience with this?  Is this a repair shop problem or user correctable?  I am unable to find a "Service Manual" for this unit also.  Many thanks for any input.  Jim Robbins

From bruce.griffiths at xtra.co.nz  Wed Oct  8 22:13:34 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Thu, 09 Oct 2008 15:13:34 +1300
Subject: [time-nuts] SR620 fails in Self Calibration routine 07
In-Reply-To: <E16CB3C0B3504DE59B9B5A17FA6EFC2C@dell8200>
References: <E16CB3C0B3504DE59B9B5A17FA6EFC2C@dell8200>
Message-ID: <48ED68CE.6030202@xtra.co.nz>

Jim Robbins wrote:
> My SR620 fails in its Self Calibration routine at "Cal Error 07".  The Users Manual describes this error as a problem with the "Start TAC" (Time to Amplitude Converters) and indicate that this flags a Hardware problem in the circuits which perform the analog interpolation between the 90 MHz clock ticks.  Anyone have any experience with this?  Is this a repair shop problem or user correctable?  I am unable to find a "Service Manual" for this unit also.  Many thanks for any input.  Jim Robbins
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>   
Jim

The TAC is a fairly straight forward circuit comprising a capacitor that 
is pre charged to a reference voltage and discharged at a constant 
current during the short time interval to be measured.
At the end of this time the voltage across the capacitor is measured by 
an ADC which also measures the STOP TAC output among other things.
Since it uses discrete components and the manual describes how it works 
in some detail it should be fairly easy to troubleshoot the circuit even 
without a schematic.

Bruce


From brooke at pacific.net  Wed Oct  8 22:54:27 2008
From: brooke at pacific.net (Brooke Clarke)
Date: Wed, 08 Oct 2008 19:54:27 -0700
Subject: [time-nuts] Datum/FTS 4065B MAJOR Fault
Message-ID: <48ED7263.2080702@pacific.net>

Hi:

Recently the Datum 4065 has developed a major fault.
Cesium fault numbers 3 & 5.
Cs fault 3 is Zeman Pedestal >160 mv
Cs fault 5 is C-Field Current > 20.0 ma

Status 3 menu sows the C-Field current at 20.2 ma.
Status 4 menu shows the C-Field Adjust at +1785 and it should be between -50 
and +50.  Also the Zeeman Beam at 0774 should be 2000 +/- 600 is out.

Status 5 menu shows both Zeeman Error of -241 S.B. <160mv and Rabi-Zeeman Error 
at +0169 S.B. < 160 mv.

Any ideas what's going on?

-- 
Have Fun,

Brooke Clarke
http://www.prc68.com


From bruce.griffiths at xtra.co.nz  Wed Oct  8 22:59:18 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Thu, 09 Oct 2008 15:59:18 +1300
Subject: [time-nuts] SR620 fails in Self Calibration routine 07
In-Reply-To: <48ED68CE.6030202@xtra.co.nz>
References: <E16CB3C0B3504DE59B9B5A17FA6EFC2C@dell8200>
	<48ED68CE.6030202@xtra.co.nz>
Message-ID: <48ED7386.8070509@xtra.co.nz>

Bruce Griffiths wrote:
> Jim Robbins wrote:
>   
>> My SR620 fails in its Self Calibration routine at "Cal Error 07".  The Users Manual describes this error as a problem with the "Start TAC" (Time to Amplitude Converters) and indicate that this flags a Hardware problem in the circuits which perform the analog interpolation between the 90 MHz clock ticks.  Anyone have any experience with this?  Is this a repair shop problem or user correctable?  I am unable to find a "Service Manual" for this unit also.  Many thanks for any input.  Jim Robbins
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>>   
>>     
> Jim
>
> The TAC is a fairly straight forward circuit comprising a capacitor that 
> is pre charged to a reference voltage and discharged at a constant 
> current during the short time interval to be measured.
> At the end of this time the voltage across the capacitor is measured by 
> an ADC which also measures the STOP TAC output among other things.
> Since it uses discrete components and the manual describes how it works 
> in some detail it should be fairly easy to troubleshoot the circuit even 
> without a schematic.
>
> Bruce
>   
According to the parts list the integrator capacitor used in the TAC is 
a 100pF Z5U unit.
If this is indeed correct then its no wonder linearisation of the TAC 
output is required.
However the sample and hold cap is sted to be polypropylene in the text 
whilst the parts list specifies polystyrene.

Bruce


From tomduck at comcast.net  Thu Oct  9 03:27:35 2008
From: tomduck at comcast.net (Tom Duckworth)
Date: Thu, 9 Oct 2008 00:27:35 -0700
Subject: [time-nuts] What is the best counter for a Time Nuts?
In-Reply-To: <48ED1954.2040906@xtra.co.nz>
Message-ID: <mailman.17.1223537278.2202.time-nuts@febo.com>

Ulrich,

Check out a Pendulum Instruments CNT-91 time stamping counter. You'll find
much better resolution. This counter doesn't work the way other
direct/reciprocal counters do. It has 50 ps resolution time resolution and
12 digits per second display.

Tom
Tom Duckworth
510-886-1396
 
-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Bruce Griffiths
Sent: Wednesday, October 08, 2008 1:34 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] What is the best counter for a Time Nuts?

Ulrich Bangert wrote:
> Gentlemen,
>
> up to now I have been thinking that I am pretty well informed about
> current counter technology but some experiences of the last days make me
> doubt. The following applies to frequency measurements of a 10 MHz
> signal.
>
> I have received some data measured with an Agilent 53131 counter from
> Time Nuts member James Miller. That data shows a resolution of 3 digits
> after the decimal point for a frequency measurement of 1 s "Gate time"
> and 4 digits for a 10 s "Gate time". 
>
> This is perfectly in line with what I thought to know about modern
> counters: Internally EVERY type of measurement is reduced to a time
> interval measurement. Since a frequency measurement with 1 s "Gate time"
> equals a time interval measurement of an 1 s interval and the counter
> has an single shot resolution of 500 ps the relative statistical error
> due to this resolution is 500 ps / 1 s = 5*E-10. As the frequency is
> computed from the time interval measurement is has the same relative
> error and for that reason displaying 3 digits after the decimal point is
> a good choice because 0.001 Hz (1E-10) is the least digit of
> significance. Using a digit more would suggest a resolution that is not
> available, using one digit less would decrease the numerical resolution
> below the measurement resolution. 
>
> Up to this point my statement of beliefs is in harmony with Agilent.
>
> Now comes the strange part: In the course of a discussion between Time
> Nuts member Bernd Neubig of AXTAL Germany and me I received data
> measured with an Agilent 53132 which is the 53131's big brother with a
> better single shot resolution of 150 ps. 
>
> I have been prepared to see this better resolution in the data but what
> I really have seen SHOCKED me a lot. Not only does the 53132 generate 5
> (!) digits after the decimal point for a 1 s "Gate time" (with 0.00001
> equal to 1E-12) a sigma tau diagram of the data revealed that the last
> digit was not only "noise" but seemed to be of real significance. I had
> been presuming that perhaps the counter's statistics had been enabled
> for that but as it turned out this was not the case. From that data one
> must make the conclusion that the overall jitter of the 53132 including
> the resolution quantification, trigger errors and everything else is
> <=5E-12 !!!!!!
>
> Big question: If the single shot resolution is only 3-4 times better
> that that of the 53131 and much inferior to the 20 ps of my SR620, how
> does the 53132 manage to be THAT GOOD A PERFORMER? Magic? Black art? 
>
> I immediatly made the same measurement with my SR620 to receive a
> counter noise floor of 6E-11 for 1 s frequency data, pretty much a
> decade worse of the 53132. Must we throw our 5370s and SR620s out of the
> window and settle for second hand  53132 from eBay to make precise
> stability measurements ???
>
> TIA for your suggestions    
>
> Ulrich Bangert
> www.ulrich-bangert.de
> Ortholzer Weg 1
> 27243 Gross Ippener 
>
>
>   
Ulrich

These effectively counters time stamp every Nth signal zero crossing and 
then fit a linear regression line to the results.
This reduces the effective noise contribution from the interpolator.
Since the noise transfer function is thereby altered over that of a 
conventional counter or reciprocal counter one cannot use the results to 
compute the Allen deviation directly.

Read the papers on the Pendulum site for further details.

http://www.pendulum-instruments.com/Assets/download/frequency_counting_artic
le.pdf

http://www.pendulum-instruments.com/Assets/download/timestamping_article.pdf

Enrico Rubiola published a paper on the effect of using the output from 
such counters in that Allen deviation calculations.

http://arxiv.org/abs/physics?papernum=0411227

A recent Australian paper purports to correct some of the errors in 
Enrico's paper, but the basic conclusion is the same one cannot 
calculate the Allen deviation directly from measurements obtained with 
such a counter.


Bruce

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to
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From XDE-L2G3 at myamail.com  Thu Oct  9 04:09:08 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Thu, 09 Oct 2008 04:09:08 -0400
Subject: [time-nuts] Testing frequency using NTP Bruce GPS ps
References: <mailman.195.1222952732.2205.time-nuts@febo.com>
	<E1KlOmJ-0007rp-88@febo.com> <48E52F08.8070400@xtra.co.nz>
	<E1KlwtS-0002lT-Ek@febo.com> <000f01c925cd$e6c84de0$0300a8c0@pc52>
	<E1KlyXH-0004HB-SC@febo.com> <005401c925f2$db402fe0$0300a8c0@pc52>
Message-ID: <mailman.18.1223539777.2202.time-nuts@febo.com>

  "Tom Van Baak" <tvb at LeapSecond.com> wrote:

  > Note another equivalent technique is to use two serial  ports; one
  > for the  receiver  (record  sawtooth corrections)  and  one  for a
  > 53132A-style counter  (record  TI measurements)  and  then  do the
  > calculations in  software. TAC32 does this. I think  TBoltMon also
  > allows it. Roughly, it's a trade-off in equipment and complexity.

  > They give essentially the same performance result.

  I have to learn more about how you do your measurements. A 53132A is
  way out  of  my price range at the moment. But I  do  have  a 53310A
  which should give comparable results.

  > There are  still  many  other sources of  noise,  both  short- and
  > long-term in  an OEM GPS receiver/antenna system. That's  why even
  > if there  were  zero  quantization error, you  would  still  see a
  > couple of ns rms error in the 1PPS output.

  I am interested in learning more about these errors. Is there a list
  somewhere that describes the sources of error, and what can  be done
  to reduce it? I keep coming across hints of doing this  in software,
  but it would seem that has to be done in the signal  processing part
  of the receiver. But we don't have access to that. Is there anything
  else we can do to help remove some of these errors?

  >> Thanks. I  had not found that page yet. Just judging  by eyeball,
  >> the pink  and  yellow traces don't seem to track  very  well. Any
  >> reason?

  > On that  plot,  the various runs weren't concurrent  so  you can't
  > look for  common-mode  effects.   Separate  runs,  showing typical
  > levels of jitter, all plotted on the same x-y scale. You've  got a
  > good eye.

  >> And what's  the blue trace for? I can't seem to  find  the parent
  >> page, so I don't know if you have already explained it.

  > This will help a bit more:

  >http://www.febo.com/pipermail/time-nuts/2005-April/018114.html

  Thanks - I'll have to study that a bit more. Right now I  can't make
  heads or  tails  of it - maybe I'm too tired and  need  to  get some
  sleep. Sure  - I just looked at the clock. It's  4am.  That explains
  it.

  >> Overall, I  was  a  little   disappointed  to  find  the sawtooth
  >> correction only gives about a factor of 3 or so improvement.

  > That's partly  because the sawtooth of the M12+ is small  to begin
  > with, at  least  compared to the earlier VP. So  there  isn't much
  > room for  sawtooth  correction to have a  massive  gain.  Also the
  > granularity of the quantization message from the receiver is 1 ns.

  That is very interesting. What do you mean by granularity? I  have a
  file somewhere  that  talks about the algorithm to  select  the next
  1PPS pulse.  It added 500ps to the rounding, so the result  would be
  on 1 ns boundaries. Is that what you meant?

  > And there's  an internal delay of one or two seconds  which  has a
  > slight effect on the quality of the correction.

  That is getting very subtle. How much effect does it have, and where
  on earth do you learn all this stuff?

  > Another way to look at it is this. If a perfect M12+ had, say, 2.5
  > ns of  jitter, and you saw 10 ns rms  without  sawtooth correction
  > and 3 ns rms with sawtooth correction you could say you achieved a
  > 15x improvement!  (10-2.5)/(3-2.5). Or if you didn't  say  it, the
  > marketing department certainly would.

  Don't you have to use the difference of squares in working  with rms
  values?

  > The closer you get to a few nanoseconds of jitter anyway, the more
  > all the  other  errors  in a typical cheap  OEM  GPS  receiver and
  > antenna system come into play. So once you average beyond a couple
  > of minutes the wander you see in the 1PPS has less and less  to do
  > with sawtooth and more to do with the sum of all the  other subtle
  > errors.

  That's what I need to learn more about.

  > Expensive geodetic  or  timing   receivers  use  an  assortment of
  > techniques to reduce the effect of these remaining  error sources,
  > to the point where you'll hear of millimeters and picoseconds (and
  > priced accordingly).

  Where can I learn more about these techniques?

  >> obtained with  my method have given over two orders  of magnitude
  >> improvement in noise reduction. That's with no optimization.

  > Averaging over  multiple samples, of course, gives a  reduction in
  > noise. You can see this in the ADEV plots at the end of:

  >http://www.leapsecond.com/pages/58503-cns2/

  That is  really  outstanding work. You have a  magic  skill  to take
  complex data  and  present  it in such a way to  make  it  clear and
  understandable.

  But to  be honest, all the noisy traces hurt my eyes. I am  now used
  to seeing  signals  with all the noise removed, so you  can  look at
  more subtle things in the waveforms.

  > On the  other  hand,  if  you found a way  to  get  two  orders of
  > magnitude better  performance  out of an M12+ without  the  use of
  > averaging then I'm all ears.

  This is  a  technique I discovered last century. It  is  really very
  simple, but  some people may have a difficult time believing  it can
  be done. So rather than waste everyone's time trying to  explain it,
  a demonstration with a credible and unbiased person such as yourself
  would probably work a lot better.

  I have  some  stuff on order, and plan to  make  two  simple systems
  using an  Oncore  UT  and a VCXO. It will take  about  two  or three
  months to  get  everything through Canadian  customs  and  build the
  prototype. It will be hand-wired, but I have developed a  new method
  of making  very rugged low-noise prototypes  suited  for frequencies
  well into the microwave region.

  When it is working, I'll make a copy and send it to you. Then if you
  would be  kind enough to make your magical measurements, I  would be
  very pleased to see the results.

  If it is what I think it will be, probably others would like  to see
  the results also.

  If you  are  interested,  I'll let you know my  progress  so  we can
  schedule a time that is convenient for you.

  >/tvb

  Best Regards,

  Mike Monett


From SAIDJACK at aol.com  Thu Oct  9 04:40:57 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Thu, 9 Oct 2008 04:40:57 EDT
Subject: [time-nuts] What is the best counter for a Time Nuts?
Message-ID: <d43.272633eb.361f1d99@aol.com>

Hi Tom, Ulrich,
 
can't seem to get 12 digits/s out of my 53132A in frequency mode when doing  
measurement offset of -10MHz. I only get 11 digits/s for some reason. Have to 
go  to 10s + gate time to get better resolution.
 
But I think I discussed this before on this forum, the highest resolution  
time interval counter available at hobby price points on Ebay is the  Wavecrest 
DTS series, and several members of this forum use these quite  successfully. 
They have a nice Windows based user interface via GPIB, or  front-panel 
operation.
 
DTS-2075 for example has 0.8ps(!) hardware resolution, 10ps typical  noise 
rms (I see more like <3ps rms noise on my units), and +/-30ps single  shot 
accuracy. They are self-calibrating using front panel buttons and some SMA  cables.
 
Lastly they can do cable-length measurements to below 1ps resolution!
 
That combined with 40K samples/s gives a lot of bang (for the buck).
 
You can measure period jitter against the internal oven with a typ. noise  
floor of 3ps, or frequency stability against an external reference. Low end  
units will measure DC to above 1GHz.
 
I have bought working units on Ebay for less than $500 in the past. But  they 
won't please everyone, they are clunky/noisy, and consume a lot of  power.
 
bye,
Said
 
 
In a message dated 10/9/2008 00:30:04 Pacific Daylight Time,  
tomduck at comcast.net writes:

Ulrich,

Check out a Pendulum Instruments CNT-91 time stamping  counter. You'll find
much better resolution. This counter doesn't work the  way other
direct/reciprocal counters do. It has 50 ps resolution time  resolution and
12 digits per second display.

Tom
Tom  Duckworth
510-886-1396




**************New MapQuest Local shows what's happening at your destination.  
Dining, Movies, Events, News & more. Try it out!      
(http://local.mapquest.com/?ncid=emlcntnew00000001)

From magnus at rubidium.dyndns.org  Thu Oct  9 04:43:42 2008
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Thu, 09 Oct 2008 10:43:42 +0200
Subject: [time-nuts] What is the best counter for a Time Nuts?
In-Reply-To: <48ED1954.2040906@xtra.co.nz>
References: <06B2020E21E7485BAE78A7667DB7CA7B@athlon>
	<48ED1954.2040906@xtra.co.nz>
Message-ID: <48EDC43E.4040001@rubidium.dyndns.org>

Bruce Griffiths wrote:
> Ulrich Bangert wrote:
>> Gentlemen,
>>
>> up to now I have been thinking that I am pretty well informed about
>> current counter technology but some experiences of the last days make me
>> doubt. The following applies to frequency measurements of a 10 MHz
>> signal.
>>
>> I have received some data measured with an Agilent 53131 counter from
>> Time Nuts member James Miller. That data shows a resolution of 3 digits
>> after the decimal point for a frequency measurement of 1 s "Gate time"
>> and 4 digits for a 10 s "Gate time". 
>>
>> This is perfectly in line with what I thought to know about modern
>> counters: Internally EVERY type of measurement is reduced to a time
>> interval measurement. Since a frequency measurement with 1 s "Gate time"
>> equals a time interval measurement of an 1 s interval and the counter
>> has an single shot resolution of 500 ps the relative statistical error
>> due to this resolution is 500 ps / 1 s = 5*E-10. As the frequency is
>> computed from the time interval measurement is has the same relative
>> error and for that reason displaying 3 digits after the decimal point is
>> a good choice because 0.001 Hz (1E-10) is the least digit of
>> significance. Using a digit more would suggest a resolution that is not
>> available, using one digit less would decrease the numerical resolution
>> below the measurement resolution. 
>>
>> Up to this point my statement of beliefs is in harmony with Agilent.
>>
>> Now comes the strange part: In the course of a discussion between Time
>> Nuts member Bernd Neubig of AXTAL Germany and me I received data
>> measured with an Agilent 53132 which is the 53131's big brother with a
>> better single shot resolution of 150 ps. 
>>
>> I have been prepared to see this better resolution in the data but what
>> I really have seen SHOCKED me a lot. Not only does the 53132 generate 5
>> (!) digits after the decimal point for a 1 s "Gate time" (with 0.00001
>> equal to 1E-12) a sigma tau diagram of the data revealed that the last
>> digit was not only "noise" but seemed to be of real significance. I had
>> been presuming that perhaps the counter's statistics had been enabled
>> for that but as it turned out this was not the case. From that data one
>> must make the conclusion that the overall jitter of the 53132 including
>> the resolution quantification, trigger errors and everything else is
>> <=5E-12 !!!!!!
>>
>> Big question: If the single shot resolution is only 3-4 times better
>> that that of the 53131 and much inferior to the 20 ps of my SR620, how
>> does the 53132 manage to be THAT GOOD A PERFORMER? Magic? Black art? 
>>
>> I immediatly made the same measurement with my SR620 to receive a
>> counter noise floor of 6E-11 for 1 s frequency data, pretty much a
>> decade worse of the 53132. Must we throw our 5370s and SR620s out of the
>> window and settle for second hand  53132 from eBay to make precise
>> stability measurements ???
>>
>> TIA for your suggestions    
>>
>> Ulrich Bangert
>> www.ulrich-bangert.de
>> Ortholzer Weg 1
>> 27243 Gross Ippener 
>>
>>
>>   
> Ulrich
> 
> These effectively counters time stamp every Nth signal zero crossing and 
> then fit a linear regression line to the results.
> This reduces the effective noise contribution from the interpolator.
> Since the noise transfer function is thereby altered over that of a 
> conventional counter or reciprocal counter one cannot use the results to 
> compute the Allen deviation directly.
> 
> Read the papers on the Pendulum site for further details.
> 
> http://www.pendulum-instruments.com/Assets/download/frequency_counting_article.pdf
> 
> http://www.pendulum-instruments.com/Assets/download/timestamping_article.pdf
> 
> Enrico Rubiola published a paper on the effect of using the output from 
> such counters in that Allen deviation calculations.
> 
> http://arxiv.org/abs/physics?papernum=0411227
> 
> A recent Australian paper purports to correct some of the errors in 
> Enrico's paper, but the basic conclusion is the same one cannot 
> calculate the Allen deviation directly from measurements obtained with 
> such a counter.

I think you mixed up the HP 53132A A-approximation with the Pendulum 
linear regression. They are two distinct methods of improvements for the 
intended application. Both have properties which does not make their 
readings appropriate for Allan deviation calculations, as indicated in 
the paper.

Ulrich particular concern was the HP 53132A and then the triangular 
approximation is the relevant one.

One should recall that the properties of a system cannot be concluded in 
a single parameter. Single-shot resolution is not everything, trigger 
jitter, low frequency modulations, cross-talk, etc. etc. all come into 
play to skew results before we can treat them by beutiful math.

Single-shot resultion is an indication at best.

Look at the HP 53132A where the single-shot resolution is 150 ps but the 
trigger jitter is only 3 ps. Those numbers behave differently to gate 
time and averaging. Increasing the gate time between a start and stop 
trigger will increase the number virtual cycles you have, but the 
trigger jitter for each start and stop will remain at 3 ps and thus 
forming the floor which pure gate time cannot reduce. For this averaging 
is needed.

This is really what those ugly formulas in the back of the manual says. 
Staffans papper above give some insight.

Cheers,
Magnus


From df6jb at ulrich-bangert.de  Thu Oct  9 04:58:18 2008
From: df6jb at ulrich-bangert.de (Ulrich Bangert)
Date: Thu, 9 Oct 2008 10:58:18 +0200
Subject: [time-nuts] What is the best counter for a Time Nuts?
In-Reply-To: <48ED296B.7090906@pacific.net>
Message-ID: <CC283535DEAA40F6903FCF9CEAC4CE3D@athlon>

Gentlemen,

first of all I would like to thank you for your feedback. 

Reading in the literature that some of you supplied revealed that modern
counters may work even more tricky than i had though but that their
"tricky output" is NOT easily taken as the input for AD computations
without additional precautions.

> The Ref Output on the front panel of the SR620 is derived 
> (1/10,000) from the 
> EXT IN on the rear panel.  So when you apply a 10 MHz signal 
> to EXT IN you get 
> a 1 kHz REF OUT.  Appendix B in the PSR10 Rubidium source 
> manual describes how 
> to use this along with the arming function to average 1,000 
> measurements per 
> second resulting in 2E-12 per second on the display.  i.e. 
> very close to the 
> HP53132A.  So no external hardware is required and no PC to 
> get this result.

After I had read this suggestion of Brooke I immediately gave it a test.
With a reference and a DUT both believed (due to other
experiements/measurements) to be stable < 3E-12 @ 1s I received the
results attached.

And of course you do not get a frequency value as

> second resulting in 2E-12 per second on the display

may indicate. The counter works in time interval mode in this
arrangement and you get 1 s data of delta ts between 0 and 100 ns that
need to be un-wrapped. I would judge that this method is well suited if
a DUT needs to be trimmed to 10 NHz with high resolution but I fear that
it does not help us in high stability measurements since the intrinsic
noise is still more than a decade too high.

Best regards
Ulrich Bangert

> -----Ursprungliche Nachricht-----
> Von: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] Im Auftrag von Brooke Clarke
> Gesendet: Mittwoch, 8. Oktober 2008 23:43
> An: Discussion of precise time and frequency measurement
> Betreff: Re: [time-nuts] What is the best counter for a Time Nuts?
> 
> 
> Hi Bruce:
> 
> The Ref Output on the front panel of the SR620 is derived 
> (1/10,000) from the 
> EXT IN on the rear panel.  So when you apply a 10 MHz signal 
> to EXT IN you get 
> a 1 kHz REF OUT.  Appendix B in the PSR10 Rubidium source 
> manual describes how 
> to use this along with the arming function to average 1,000 
> measurements per 
> second resulting in 2E-12 per second on the display.  i.e. 
> very close to the 
> HP53132A.  So no external hardware is required and no PC to 
> get this result.
> 
> Have Fun,
> 
> Brooke Clarke
> http://www.prc68.com
> http://www.precisionclock.com
> 
> 
> Bruce Griffiths wrote:
> .....
> > 
> > It is also possible to use a SR620 or a 5370 to take 1000 
> > timestamps/sec. However may require using some external hardware 
> > (frequency divider). For maximum accuracy and precision the 
> resultant 
> > data has to be logged and processed off line using a PC or other 
> > computer.
> > 
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-> bin/mailman/listinfo/time-nuts
> and 
> follow the instructions there.
> 
-------------- next part --------------
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From bruce.griffiths at xtra.co.nz  Thu Oct  9 08:08:58 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Fri, 10 Oct 2008 01:08:58 +1300
Subject: [time-nuts] What is the best counter for a Time Nuts?
In-Reply-To: <48EDC43E.4040001@rubidium.dyndns.org>
References: <06B2020E21E7485BAE78A7667DB7CA7B@athlon>	<48ED1954.2040906@xtra.co.nz>
	<48EDC43E.4040001@rubidium.dyndns.org>
Message-ID: <48EDF45A.8080003@xtra.co.nz>

Magnus Danielson wrote:
> I think you mixed up the HP 53132A A-approximation with the Pendulum 
> linear regression. They are two distinct methods of improvements for the 
> intended application. Both have properties which does not make their 
> readings appropriate for Allan deviation calculations, as indicated in 
> the paper.
>
> Ulrich particular concern was the HP 53132A and then the triangular 
> approximation is the relevant one.
>
> One should recall that the properties of a system cannot be concluded in 
> a single parameter. Single-shot resolution is not everything, trigger 
> jitter, low frequency modulations, cross-talk, etc. etc. all come into 
> play to skew results before we can treat them by beutiful math.
>
> Single-shot resultion is an indication at best.
>
> Look at the HP 53132A where the single-shot resolution is 150 ps but the 
> trigger jitter is only 3 ps. Those numbers behave differently to gate 
> time and averaging. Increasing the gate time between a start and stop 
> trigger will increase the number virtual cycles you have, but the 
> trigger jitter for each start and stop will remain at 3 ps and thus 
> forming the floor which pure gate time cannot reduce. For this averaging 
> is needed.
>
> This is really what those ugly formulas in the back of the manual says. 
> Staffans papper above give some insight.
>
> Cheers,
> Magnus
>   
Magnus

When measuring the frequency of a signal using a conventional counter, 
increasing the gate time decreases the noise contribution of trigger 
jitter to frequency measurement noise although jitter is invariant with 
gate time. The jitter simply becomes a smaller fraction of the total 
gate time. Similarly the frequency measurement resolution increases with 
increasing gate time although the resolution (measured in picoseconds) 
is invariant with gate time it simply becomes a smaller fraction of the 
total gate time.

However if one timestamps a few more signal zero crossings within the 
gate time interval than just those and the start and end of the gate 
time lower noise estimators of the frequency are available.

The HP53132 averages the frequency estimates for a series of identical 
duration overlapped gate times.
Enrico's paper analyses this case.
The Australian paper corrects some of the errors in Enrico's analysis 
and hints how the analysis may be extended to cover the case of counters 
that use other resolution enhancement techniques.

Counters like the Pendulum CNT91 in effect time stamp every Nth zero 
crossing of the signal and fit a linear regression line to the sequence 
of time stamps. The frequency is then estimated from the slope of the 
regression line. However the CNT91 has limited memory and processing 
power so that full advantage isnt taken of the resolution offered by 
this technique.
AFAIK no one has yet done a similar analysis to that done for the 
"triangular" averaging counter (by Enrico and the Australians) for a 
counter that does a regression line fit.

Bruce


From magnus at rubidium.dyndns.org  Thu Oct  9 09:52:34 2008
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Thu, 9 Oct 2008 15:52:34 +0200 (CEST)
Subject: [time-nuts] What is the best counter for a Time Nuts?
In-Reply-To: <48EDF45A.8080003@xtra.co.nz>
References: <06B2020E21E7485BAE78A7667DB7CA7B@athlon>
	<48ED1954.2040906@xtra.co.nz> <48EDC43E.4040001@rubidium.dyndns.org>
	<48EDF45A.8080003@xtra.co.nz>
Message-ID: <40ff0c7dcde9a80df4d514b447ac493f.squirrel@rubidium.dyndns.org>

Bruce,

> When measuring the frequency of a signal using a conventional counter,
> increasing the gate time decreases the noise contribution of trigger
> jitter to frequency measurement noise although jitter is invariant with
> gate time. The jitter simply becomes a smaller fraction of the total
> gate time. Similarly the frequency measurement resolution increases with
> increasing gate time although the resolution (measured in picoseconds)
> is invariant with gate time it simply becomes a smaller fraction of the
> total gate time.

True, I was being a bit sloppy there...

> However if one timestamps a few more signal zero crossings within the
> gate time interval than just those and the start and end of the gate
> time lower noise estimators of the frequency are available.

Indeed.

> The HP53132 averages the frequency estimates for a series of identical
> duration overlapped gate times.
> Enrico's paper analyses this case.
> The Australian paper corrects some of the errors in Enrico's analysis
> and hints how the analysis may be extended to cover the case of counters
> that use other resolution enhancement techniques.

Recommended reading!

> Counters like the Pendulum CNT91 in effect time stamp every Nth zero
> crossing of the signal and fit a linear regression line to the sequence
> of time stamps. The frequency is then estimated from the slope of the
> regression line. However the CNT91 has limited memory and processing
> power so that full advantage isnt taken of the resolution offered by
> this technique.
> AFAIK no one has yet done a similar analysis to that done for the
> "triangular" averaging counter (by Enrico and the Australians) for a
> counter that does a regression line fit.

Actually, as I recall it, there was a note in one of those articles
relating to it, but your could figure out that it was rendering about the
same conclusion. It also makes sense.

Cheers,
Magnus


From tvb at LeapSecond.com  Thu Oct  9 10:54:56 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Thu, 9 Oct 2008 07:54:56 -0700
Subject: [time-nuts] What is the best counter for a Time Nuts?
References: <d43.272633eb.361f1d99@aol.com>
Message-ID: <002f01c92a1e$fed75480$2801a8c0@pc52>

> Hi Tom, Ulrich,
> 
> can't seem to get 12 digits/s out of my 53132A in frequency mode when doing  
> measurement offset of -10MHz. I only get 11 digits/s for some reason. Have to 
> go  to 10s + gate time to get better resolution.

Correct. When you get "close" to an exact 10 MHz input then
the counter drops down into a "reduced resolution" mode and
you lose a digit (regardless of gate time). If you need, you can
query this with the :DIAG:MEAS:PRES? command. Details are
in the back of the 53132A manual.

/tvb



From magnus at rubidium.dyndns.org  Thu Oct  9 11:46:26 2008
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Thu, 9 Oct 2008 17:46:26 +0200 (CEST)
Subject: [time-nuts] What is the best counter for a Time Nuts?
In-Reply-To: <002f01c92a1e$fed75480$2801a8c0@pc52>
References: <d43.272633eb.361f1d99@aol.com>
	<002f01c92a1e$fed75480$2801a8c0@pc52>
Message-ID: <a226d1ba76f3fde830fd410db77b124f.squirrel@rubidium.dyndns.org>

>> Hi Tom, Ulrich,
>>
>> can't seem to get 12 digits/s out of my 53132A in frequency mode when
>> doing
>> measurement offset of -10MHz. I only get 11 digits/s for some reason.
>> Have to
>> go  to 10s + gate time to get better resolution.
>
> Correct. When you get "close" to an exact 10 MHz input then
> the counter drops down into a "reduced resolution" mode and
> you lose a digit (regardless of gate time). If you need, you can
> query this with the :DIAG:MEAS:PRES? command. Details are
> in the back of the 53132A manual.

"Additional Considerations for Digits and Time Arming Modes" (at page 3-13
in my version of the manual).

Cheers,
Magnus


From SAIDJACK at aol.com  Thu Oct  9 12:15:12 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Thu, 9 Oct 2008 12:15:12 EDT
Subject: [time-nuts] What is the best counter for a Time Nuts?
Message-ID: <cb2.42e08880.361f8810@aol.com>

Hi guys,
 
thanks for the hint, this explains it.
 
read the manual, and so it seems I cannot use time arming mode. How do you  
guys get around this? Do A to B measurements on the two channels?
 
thanks,
Said
 
 
In a message dated 10/9/2008 08:49:59 Pacific Daylight Time,  
magnus at rubidium.dyndns.org writes:

>>  Hi Tom, Ulrich,
>>
>> can't seem to get 12 digits/s out of  my 53132A in frequency mode when
>> doing
>> measurement  offset of -10MHz. I only get 11 digits/s for some reason.
>> Have  to
>> go  to 10s + gate time to get better  resolution.
>
> Correct. When you get "close" to an exact 10 MHz  input then
> the counter drops down into a "reduced resolution" mode  and
> you lose a digit (regardless of gate time). If you need, you  can
> query this with the :DIAG:MEAS:PRES? command. Details are
>  in the back of the 53132A manual.

"Additional Considerations for Digits  and Time Arming Modes" (at page 3-13
in my version of the  manual).

Cheers,
Magnus

_______________________________________________
time-nuts  mailing list -- time-nuts at febo.com
To unsubscribe, go to  https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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Dining, Movies, Events, News & more. Try it out!      
(http://local.mapquest.com/?ncid=emlcntnew00000001)

From magnus at rubidium.dyndns.org  Thu Oct  9 14:12:04 2008
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Thu, 9 Oct 2008 20:12:04 +0200 (CEST)
Subject: [time-nuts] What is the best counter for a Time Nuts?
Message-ID: <16f5a1deb62a97e6b570d0207a6204a2.squirrel@rubidium.dyndns.org>

Tom Duckworth wrote:
> Ulrich,
>
> Check out a Pendulum Instruments CNT-91 time stamping counter. You'll
find
> much better resolution. This counter doesn't work the way other
> direct/reciprocal counters do. It has 50 ps resolution time resolution
and
> 12 digits per second display.

The actual resolution is higher, but 50 ps is the published number.

Cheers,
Magnus






From bruce.griffiths at xtra.co.nz  Thu Oct  9 16:35:43 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Fri, 10 Oct 2008 09:35:43 +1300
Subject: [time-nuts] What is the best counter for a Time Nuts?
In-Reply-To: <40ff0c7dcde9a80df4d514b447ac493f.squirrel@rubidium.dyndns.org>
References: <06B2020E21E7485BAE78A7667DB7CA7B@athlon>	<48ED1954.2040906@xtra.co.nz>
	<48EDC43E.4040001@rubidium.dyndns.org>	<48EDF45A.8080003@xtra.co.nz>
	<40ff0c7dcde9a80df4d514b447ac493f.squirrel@rubidium.dyndns.org>
Message-ID: <48EE6B1F.2080006@xtra.co.nz>

Magnus Danielson wrote:
> Bruce,
>
>   
>> When measuring the frequency of a signal using a conventional counter,
>> increasing the gate time decreases the noise contribution of trigger
>> jitter to frequency measurement noise although jitter is invariant with
>> gate time. The jitter simply becomes a smaller fraction of the total
>> gate time. Similarly the frequency measurement resolution increases with
>> increasing gate time although the resolution (measured in picoseconds)
>> is invariant with gate time it simply becomes a smaller fraction of the
>> total gate time.
>>     
>
> True, I was being a bit sloppy there...
>
>   
>> However if one timestamps a few more signal zero crossings within the
>> gate time interval than just those and the start and end of the gate
>> time lower noise estimators of the frequency are available.
>>     
>
> Indeed.
>
>   
>> The HP53132 averages the frequency estimates for a series of identical
>> duration overlapped gate times.
>> Enrico's paper analyses this case.
>> The Australian paper corrects some of the errors in Enrico's analysis
>> and hints how the analysis may be extended to cover the case of counters
>> that use other resolution enhancement techniques.
>>     
>
> Recommended reading!
>
>   
>> Counters like the Pendulum CNT91 in effect time stamp every Nth zero
>> crossing of the signal and fit a linear regression line to the sequence
>> of time stamps. The frequency is then estimated from the slope of the
>> regression line. However the CNT91 has limited memory and processing
>> power so that full advantage isnt taken of the resolution offered by
>> this technique.
>> AFAIK no one has yet done a similar analysis to that done for the
>> "triangular" averaging counter (by Enrico and the Australians) for a
>> counter that does a regression line fit.
>>     
>
> Actually, as I recall it, there was a note in one of those articles
> relating to it, but your could figure out that it was rendering about the
> same conclusion. It also makes sense.
>
> Cheers,
> Magnus
>   
Hej Magnus

Of course such enhanced resolution techniques arent restricted purely to 
frequency measurement.
An analogous technique can be used in an integrating DVM where the 
integrator output is sampled periodically during the signal integration.
Even when a "multislope" technique is used during integrator runup, such 
a technique can be used.
In this case a form of sigma delta modulation is used to keep the 
integrator output within bounds and minimise the effect of dielectric 
absorption.
The accumulated quantised feedback is combined with the sampled 
integrator residue to form the equivalent of samples taken from an ideal 
integrator with a very large output range.
One can then use regression techniques to fit a straight line (or other 
curve) to the integrator output.
This will be most effective when the noise of the ADC used to sample the 
integrator residue is the dominant noise source and the input signal is 
relatively quiet with no significant spurious frequency components.

Bruce



From Paul.Reeves at uk.thalesgroup.com  Fri Oct 10 03:11:21 2008
From: Paul.Reeves at uk.thalesgroup.com (Reeves Paul)
Date: Fri, 10 Oct 2008 08:11:21 +0100
Subject: [time-nuts] Sulzer Labs D-5 oscillator
Message-ID: <8E8D23D235D70840B6582917DF27898006935BCD@temps153538.tms-ltd.com>

Hi all,
 
I need a bit of help getting an old Sulzer D-5 5MHz oscillator to work. It
was built into a rack module with monitoring facilities and had been
slightly 'got-at' by the previous owner. Some of the connections were
pencilled on the case but not enough to give confidence about powering it
up. Has anybody got any information on this 'classic' design? Pin connection
data would be a great help, anything more would be wonderful!!
 
Thanks in advance,
 
Paul Reeves,    G8GJA

This email, including any attachment, is a confidential communication
intended solely for the use of the individual or entity to whom it is
addressed. It contains information which is private and may be proprietary
or covered by legal professional privilege. If you have received this email
in error, please notify the sender upon receipt, and immediately delete it
from your system.

Anything contained in this email that is not connected with the businesses
of this company is neither endorsed by nor is the liability of this company.

Whilst we have taken reasonable precautions to ensure that any attachment to
this email has been swept for viruses, we cannot accept liability for any
damage sustained as a result of software viruses, and would advise that you
carry out your own virus checks before opening any attachment.


From sar10538 at gmail.com  Fri Oct 10 03:12:42 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Fri, 10 Oct 2008 20:12:42 +1300
Subject: [time-nuts] PPS sync from NTP
Message-ID: <1231b6a80810100012y5e66d453wb2b9a2b4f24affb5@mail.gmail.com>

I was thinking about what has been recently discussed about the
possibility of measuring frequency via time-stamping samples
referenced to NTP and crunching the numbers. On a different vein, it
would be possible to make a PC output PPS from the internal clock
synchronised to NTP. OK, all the existing arguments about the accuracy
and stability of this still exist but it should then be possible to
sync a ocxo with this PPS to make a frequency standard suitable for a
number of uses, although not up to TN standards, agreed

73,
Steve ZL3TUV
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From sar10538 at gmail.com  Fri Oct 10 03:37:01 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Fri, 10 Oct 2008 20:37:01 +1300
Subject: [time-nuts] Sulzer Labs D-5 oscillator
In-Reply-To: <8E8D23D235D70840B6582917DF27898006935BCD@temps153538.tms-ltd.com>
References: <8E8D23D235D70840B6582917DF27898006935BCD@temps153538.tms-ltd.com>
Message-ID: <1231b6a80810100037v208b06beue1780e46ea8da87b@mail.gmail.com>

2008/10/10 Reeves Paul <Paul.Reeves at uk.thalesgroup.com>:
> Hi all,
>
> I need a bit of help getting an old Sulzer D-5 5MHz oscillator to work. It
> was built into a rack module with monitoring facilities and had been
> slightly 'got-at' by the previous owner. Some of the connections were
> pencilled on the case but not enough to give confidence about powering it
> up. Has anybody got any information on this 'classic' design? Pin connection
> data would be a great help, anything more would be wonderful!!
>
> Thanks in advance,
>
> Paul Reeves,    G8GJA
>
> This email, including any attachment, is a confidential communication
> intended solely for the use of the individual or entity to whom it is
> addressed. It contains information which is private and may be proprietary
> or covered by legal professional privilege. If you have received this email
> in error, please notify the sender upon receipt, and immediately delete it
> from your system.
>
> Anything contained in this email that is not connected with the businesses
> of this company is neither endorsed by nor is the liability of this company.
>
> Whilst we have taken reasonable precautions to ensure that any attachment to
> this email has been swept for viruses, we cannot accept liability for any
> damage sustained as a result of software viruses, and would advise that you
> carry out your own virus checks before opening any attachment.

I love that the disclaimer attached to this email is longer than the
email itself. It's a new form of spam, inflate the amount of data on
the Net by doubling the size of emails with these stupid disclaimers.
Sorry Paul, this is not aimed at you at all.

73, Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From rk at timing-consultants.com  Fri Oct 10 03:52:33 2008
From: rk at timing-consultants.com (Rob Kimberley)
Date: Fri, 10 Oct 2008 08:52:33 +0100
Subject: [time-nuts] Sulzer Labs D-5 oscillator
In-Reply-To: <1231b6a80810100037v208b06beue1780e46ea8da87b@mail.gmail.com>
References: <8E8D23D235D70840B6582917DF27898006935BCD@temps153538.tms-ltd.com>
	<1231b6a80810100037v208b06beue1780e46ea8da87b@mail.gmail.com>
Message-ID: <546315AF00DE4E928823953256F078C3@Robin>

Paul can you send me a photo of your oscillator?

Cheers

Rob Kimberley


-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Steve Rooke
Sent: 10 October 2008 08:37
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Sulzer Labs D-5 oscillator

2008/10/10 Reeves Paul <Paul.Reeves at uk.thalesgroup.com>:
> Hi all,
>
> I need a bit of help getting an old Sulzer D-5 5MHz oscillator to 
> work. It was built into a rack module with monitoring facilities and 
> had been slightly 'got-at' by the previous owner. Some of the 
> connections were pencilled on the case but not enough to give 
> confidence about powering it up. Has anybody got any information on 
> this 'classic' design? Pin connection data would be a great help, anything
more would be wonderful!!
>
> Thanks in advance,
>
> Paul Reeves,    G8GJA
>
> This email, including any attachment, is a confidential communication 
> intended solely for the use of the individual or entity to whom it is 
> addressed. It contains information which is private and may be 
> proprietary or covered by legal professional privilege. If you have 
> received this email in error, please notify the sender upon receipt, 
> and immediately delete it from your system.
>
> Anything contained in this email that is not connected with the 
> businesses of this company is neither endorsed by nor is the liability of
this company.
>
> Whilst we have taken reasonable precautions to ensure that any 
> attachment to this email has been swept for viruses, we cannot accept 
> liability for any damage sustained as a result of software viruses, 
> and would advise that you carry out your own virus checks before opening
any attachment.

I love that the disclaimer attached to this email is longer than the email
itself. It's a new form of spam, inflate the amount of data on the Net by
doubling the size of emails with these stupid disclaimers.
Sorry Paul, this is not aimed at you at all.

73, Steve
--
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



From rk at timing-consultants.com  Fri Oct 10 03:52:54 2008
From: rk at timing-consultants.com (Rob Kimberley)
Date: Fri, 10 Oct 2008 08:52:54 +0100
Subject: [time-nuts] Sulzer Labs D-5 oscillator
In-Reply-To: <1231b6a80810100037v208b06beue1780e46ea8da87b@mail.gmail.com>
References: <8E8D23D235D70840B6582917DF27898006935BCD@temps153538.tms-ltd.com>
	<1231b6a80810100037v208b06beue1780e46ea8da87b@mail.gmail.com>
Message-ID: <995765D00C9A462CAED3D7B3FE1865C7@Robin>


One of the advantages of top posting - you can reply to the message and
ignore the rubbish at the bottom....

Rob Kimberley 

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Steve Rooke
Sent: 10 October 2008 08:37
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Sulzer Labs D-5 oscillator

2008/10/10 Reeves Paul <Paul.Reeves at uk.thalesgroup.com>:
> Hi all,
>
> I need a bit of help getting an old Sulzer D-5 5MHz oscillator to 
> work. It was built into a rack module with monitoring facilities and 
> had been slightly 'got-at' by the previous owner. Some of the 
> connections were pencilled on the case but not enough to give 
> confidence about powering it up. Has anybody got any information on 
> this 'classic' design? Pin connection data would be a great help, anything
more would be wonderful!!
>
> Thanks in advance,
>
> Paul Reeves,    G8GJA
>
> This email, including any attachment, is a confidential communication 
> intended solely for the use of the individual or entity to whom it is 
> addressed. It contains information which is private and may be 
> proprietary or covered by legal professional privilege. If you have 
> received this email in error, please notify the sender upon receipt, 
> and immediately delete it from your system.
>
> Anything contained in this email that is not connected with the 
> businesses of this company is neither endorsed by nor is the liability of
this company.
>
> Whilst we have taken reasonable precautions to ensure that any 
> attachment to this email has been swept for viruses, we cannot accept 
> liability for any damage sustained as a result of software viruses, 
> and would advise that you carry out your own virus checks before opening
any attachment.

I love that the disclaimer attached to this email is longer than the email
itself. It's a new form of spam, inflate the amount of data on the Net by
doubling the size of emails with these stupid disclaimers.
Sorry Paul, this is not aimed at you at all.

73, Steve
--
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



From wb6bnq at cox.net  Fri Oct 10 03:58:05 2008
From: wb6bnq at cox.net (WB6BNQ)
Date: Fri, 10 Oct 2008 00:58:05 -0700
Subject: [time-nuts] Sulzer Labs D-5 oscillator
References: <8E8D23D235D70840B6582917DF27898006935BCD@temps153538.tms-ltd.com>
	<1231b6a80810100037v208b06beue1780e46ea8da87b@mail.gmail.com>
	<546315AF00DE4E928823953256F078C3@Robin>
Message-ID: <48EF0B0D.A2AF8A3@cox.net>

Paul,

Send me a photo as well please.  I have a Sulzer 1150 5MHz oscillator and am
curious if it looks the same.

Bill....WB6BNQ
wb6bnq at cox.net


Rob Kimberley wrote:

> Paul can you send me a photo of your oscillator?
>
> Cheers
>
> Rob Kimberley
>
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
> Behalf Of Steve Rooke
> Sent: 10 October 2008 08:37
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Sulzer Labs D-5 oscillator
>
> 2008/10/10 Reeves Paul <Paul.Reeves at uk.thalesgroup.com>:
> > Hi all,
> >
> > I need a bit of help getting an old Sulzer D-5 5MHz oscillator to
> > work. It was built into a rack module with monitoring facilities and
> > had been slightly 'got-at' by the previous owner. Some of the
> > connections were pencilled on the case but not enough to give
> > confidence about powering it up. Has anybody got any information on
> > this 'classic' design? Pin connection data would be a great help, anything
> more would be wonderful!!
> >
> > Thanks in advance,
> >
> > Paul Reeves,    G8GJA
> >
> > This email, including any attachment, is a confidential communication
> > intended solely for the use of the individual or entity to whom it is
> > addressed. It contains information which is private and may be
> > proprietary or covered by legal professional privilege. If you have
> > received this email in error, please notify the sender upon receipt,
> > and immediately delete it from your system.
> >
> > Anything contained in this email that is not connected with the
> > businesses of this company is neither endorsed by nor is the liability of
> this company.
> >
> > Whilst we have taken reasonable precautions to ensure that any
> > attachment to this email has been swept for viruses, we cannot accept
> > liability for any damage sustained as a result of software viruses,
> > and would advise that you carry out your own virus checks before opening
> any attachment.
>
> I love that the disclaimer attached to this email is longer than the email
> itself. It's a new form of spam, inflate the amount of data on the Net by
> doubling the size of emails with these stupid disclaimers.
> Sorry Paul, this is not aimed at you at all.
>
> 73, Steve
> --
> Steve Rooke - ZL3TUV & G8KVD
> Omnium finis imminet
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.



From df6jb at ulrich-bangert.de  Fri Oct 10 04:11:19 2008
From: df6jb at ulrich-bangert.de (Ulrich Bangert)
Date: Fri, 10 Oct 2008 10:11:19 +0200
Subject: [time-nuts] PLOTTER & EZGPIB
Message-ID: <AD67111641F842279BA1C46724E1271A@athlon>

Gentlemen,

new versions of PLOTTER and EZGPIB are available. Some bugs concerning
the search for Prologix serial & network controllers have been removed
and the possibility has been included to log the messages from the debug
window into a file.

PLOTTER now can compute the mean and the SD of a series only on the part
of the series that is displayed, i.e. you can zoom in to parts of the
series and compute mean & SD for the displayed part only.

Enjoy

Ulrich Bangert
www.ulrich-bangert.de
Ortholzer Weg 1
27243 Gross Ippener 



From rdarlington at gmail.com  Fri Oct 10 10:06:44 2008
From: rdarlington at gmail.com (Robert Darlington)
Date: Fri, 10 Oct 2008 08:06:44 -0600
Subject: [time-nuts] Looking for a Efratom FRS-C connector
In-Reply-To: <20081008224203.31A771165C3@hamburg.alientech.net>
References: <b3bd5fcb0810081511w7af284fke11e4ff0cec6402c@mail.gmail.com>
	<20081008224203.31A771165C3@hamburg.alientech.net>
Message-ID: <b3bd5fcb0810100706x597d01f6m1e9aba4055578dd4@mail.gmail.com>

Hi Mike,

I ordered the shell, that was easy enough to find once I had a good part
number.  I wasn't sure on the coax connector so I bought one of each.  I
have a roll of some skinny coax which I believe is RG174, but wasn't
positive.  Instead of driving into work to check, I opted to just buy the
other type of connector.  Also, not knowing what gender, I had to buy one of
each.  The oscillator is still in transit and not on my desk to examine.

Thank you to all that responded.  I appreciate the knowledge base and hope I
can reciprocate some day.

-Bob

On Wed, Oct 8, 2008 at 4:42 PM, Mike S <mikes at flatsurface.com> wrote:

> At 06:11 PM 10/8/2008, Robert Darlington wrote...
> >Hello all,
> >
> >Would any of you happen to know where I can find a mating connector
> >for the
> >Efratom FRS-C rubidium standard?  I see one eBay ad via a Google
> >search
> >listing it as a "Cannon P/N DAM11WIS", but searches on the ITT/Cannon
> >website don't turn up any hits.    Is this a valid part number?
>
> FCT makes them, and they're available from Mouser.
>
> Here's the catalog page: http://www.mouser.com/catalog/635/1223.pdf
>
> Mouser P/Ns: 152-FM11W1S-K121 (connector shell), 152-FMX006P102 (50 ohm
> crimp/solder coax contact for RG-174U sized cable)
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

From tvb at LeapSecond.com  Fri Oct 10 10:17:10 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Fri, 10 Oct 2008 07:17:10 -0700
Subject: [time-nuts] Sulzer Labs D-5 oscillator
References: <8E8D23D235D70840B6582917DF27898006935BCD@temps153538.tms-ltd.com>
Message-ID: <002f01c92ae2$e2d623f0$2801a8c0@pc52>

> Hi all,
> 
> I need a bit of help getting an old Sulzer D-5 5MHz oscillator to work. It
> was built into a rack module with monitoring facilities and had been
> slightly 'got-at' by the previous owner. Some of the connections were
> pencilled on the case but not enough to give confidence about powering it
> up. Has anybody got any information on this 'classic' design? Pin connection
> data would be a great help, anything more would be wonderful!!
> 
> Thanks in advance,
> 
> Paul Reeves,    G8GJA

Does it look like either of these?

http://leapsecond.com/museum/sul25-1/
http://leapsecond.com/museum/sul25-2/

/tvb



From scmcgrath at gmail.com  Fri Oct 10 13:14:44 2008
From: scmcgrath at gmail.com (Scott McGrath)
Date: Fri, 10 Oct 2008 13:14:44 -0400
Subject: [time-nuts] Stripped FTS 4050 on ebay 330277362819
Message-ID: <c9ffea950810101014y14e67b19m4e5a771a301df15c@mail.gmail.com>

Tube and Oscilliators look like they are missing


From mikes at flatsurface.com  Fri Oct 10 14:01:02 2008
From: mikes at flatsurface.com (Mike S)
Date: Fri, 10 Oct 2008 14:01:02 -0400
Subject: [time-nuts] Looking for a Efratom FRS-C connector
In-Reply-To: <b3bd5fcb0810100706x597d01f6m1e9aba4055578dd4@mail.gmail.co
 m>
References: <b3bd5fcb0810081511w7af284fke11e4ff0cec6402c@mail.gmail.com>
	<20081008224203.31A771165C3@hamburg.alientech.net>
	<b3bd5fcb0810100706x597d01f6m1e9aba4055578dd4@mail.gmail.com>
Message-ID: <20081010180742.183DC1165C3@hamburg.alientech.net>


>On Wed, Oct 8, 2008 at 4:42 PM, Mike S <mikes at flatsurface.com> wrote:
>
> > Mouser P/Ns: 152-FM11W1S-K121 (connector shell), 152-FMX006P102 (50 
> ohm
> > crimp/solder coax contact for RG-174U sized cable)

At 10:06 AM 10/10/2008, Robert Darlington wrote...
>I wasn't sure on the coax connector...not knowing what gender, I had 
>to buy one of each.

The shell needs a "plug" type coax contact - indicated by the "P" in 
the part number above. The FRS itself has a "socket" type, which would 
be indicated by an "S." Unlike most connectors, the reference is to the 
outer (ground) contact (!). I used the part numbers given with some 
RG-188A/U (Belden 83269), and it worked great.  



From w3kl at w3kl.com  Fri Oct 10 14:08:42 2008
From: w3kl at w3kl.com (Jeffrey Okamitsu)
Date: Fri, 10 Oct 2008 11:08:42 -0700 (PDT)
Subject: [time-nuts] Symmetricom SA.31m
Message-ID: <2760.52734.qm@web35402.mail.mud.yahoo.com>

Hi.
?
Does anyone know if the Symmetricom SA.31m is pin compatible with "standard" OXCOs used in com gear and test instruments?
?
I would make sense that it was, but then again...
?
Also, does anyone know off hand the price of new SA.31m's in small quantities?
?
Thanks!
?
Jeff

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

From rk at timing-consultants.com  Fri Oct 10 14:22:53 2008
From: rk at timing-consultants.com (Rob Kimberley)
Date: Fri, 10 Oct 2008 19:22:53 +0100
Subject: [time-nuts] Sulzer Labs D-5 oscillator
In-Reply-To: <48EF0B0D.A2AF8A3@cox.net>
References: <8E8D23D235D70840B6582917DF27898006935BCD@temps153538.tms-ltd.com><1231b6a80810100037v208b06beue1780e46ea8da87b@mail.gmail.com><546315AF00DE4E928823953256F078C3@Robin>
	<48EF0B0D.A2AF8A3@cox.net>
Message-ID: <152E6980C8B2439999C1BE4865DC0032@Robin>

The reason I asked is that  AFIK Austron acquired the Sulzer line and
therefore we can probably go down an Austron route regarding any
documentation.

Rob Kimberley




Paul,

Send me a photo as well please.  I have a Sulzer 1150 5MHz oscillator and am
curious if it looks the same.

Bill....WB6BNQ
wb6bnq at cox.net


Rob Kimberley wrote:

> Paul can you send me a photo of your oscillator?
>
> Cheers
>
> Rob Kimberley
>
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] 
> On Behalf Of Steve Rooke
> Sent: 10 October 2008 08:37
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Sulzer Labs D-5 oscillator
>
> 2008/10/10 Reeves Paul <Paul.Reeves at uk.thalesgroup.com>:
> > Hi all,
> >
> > I need a bit of help getting an old Sulzer D-5 5MHz oscillator to 
> > work. It was built into a rack module with monitoring facilities and 
> > had been slightly 'got-at' by the previous owner. Some of the 
> > connections were pencilled on the case but not enough to give 
> > confidence about powering it up. Has anybody got any information on 
> > this 'classic' design? Pin connection data would be a great help, 
> > anything
> more would be wonderful!!
> >
> > Thanks in advance,
> >
> > Paul Reeves,    G8GJA
> >
> > This email, including any attachment, is a confidential 
> > communication intended solely for the use of the individual or 
> > entity to whom it is addressed. It contains information which is 
> > private and may be proprietary or covered by legal professional 
> > privilege. If you have received this email in error, please notify 
> > the sender upon receipt, and immediately delete it from your system.
> >
> > Anything contained in this email that is not connected with the 
> > businesses of this company is neither endorsed by nor is the 
> > liability of
> this company.
> >
> > Whilst we have taken reasonable precautions to ensure that any 
> > attachment to this email has been swept for viruses, we cannot 
> > accept liability for any damage sustained as a result of software 
> > viruses, and would advise that you carry out your own virus checks 
> > before opening
> any attachment.
>
> I love that the disclaimer attached to this email is longer than the 
> email itself. It's a new form of spam, inflate the amount of data on 
> the Net by doubling the size of emails with these stupid disclaimers.
> Sorry Paul, this is not aimed at you at all.
>
> 73, Steve
> --
> Steve Rooke - ZL3TUV & G8KVD
> Omnium finis imminet
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.


_______________________________________________
time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



From true-cal at swbell.net  Fri Oct 10 16:02:30 2008
From: true-cal at swbell.net (Don @ True-Cal)
Date: Fri, 10 Oct 2008 13:02:30 -0700 (PDT)
Subject: [time-nuts] PLOTTER & EZGPIB
Message-ID: <11567.33191.qm@web81803.mail.mud.yahoo.com>

Ulrich,

I have been wanting to try your EZGPIB to control and capture data from various instruments I run in my lab. My GPIB bus typically has 3-6 instruments connected and I currently use the NI GPIB-ENET/100 as a LAN bridge to any one of several?windows based computers. Ocassionally, I also use the?NI GPIB-USB-A connected to a single instrument. In either case, I use the NI drivers and NI-488.2 ver 2.1 on WinXP. My control applications to date have been limited to Agilent VEE Pro along with the Agilent IO library suite. Can you comment on any known problems or issues I might encounter using EZGPIB with the above hardware or VISA API configuration/s. The instruments I may have on the bus are:
SR620
HP 53181A
HP 5372A
HP 3457A
HP 8903B
Keithley 2002

Thanks...
Don


----- Original Message ----
From: Ulrich Bangert <df6jb at ulrich-bangert.de>
To: Time nuts <time-nuts at febo.com>
Sent: Friday, October 10, 2008 3:11:19 AM
Subject: [time-nuts] PLOTTER & EZGPIB

Gentlemen,

new versions of PLOTTER and EZGPIB are available. Some bugs concerning
the search for Prologix serial & network controllers have been removed
and the possibility has been included to log the messages from the debug
window into a file.

PLOTTER now can compute the mean and the SD of a series only on the part
of the series that is displayed, i.e. you can zoom in to parts of the
series and compute mean & SD for the displayed part only.

Enjoy

Ulrich Bangert
www.ulrich-bangert.de
Ortholzer Weg 1
27243 Gross Ippener 


_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

From w3kl at w3kl.com  Fri Oct 10 16:12:19 2008
From: w3kl at w3kl.com (Jeffrey Okamitsu)
Date: Fri, 10 Oct 2008 13:12:19 -0700 (PDT)
Subject: [time-nuts] Agilent 5071A
Message-ID: <476490.13171.qm@web35402.mail.mud.yahoo.com>

Hi.? Will the beam tube in a 5071A work in a 5061B?
?
I suspect not, but I defer to experts out there.
?
Jeff

Jeffrey K. Okamitsu, PhD, MBA
+1-609-638-5402

From vilgotch at bigpond.net.au  Fri Oct 10 22:36:14 2008
From: vilgotch at bigpond.net.au (Morris Odell)
Date: Sat, 11 Oct 2008 13:36:14 +1100
Subject: [time-nuts] Lassen IQ receiver
Message-ID: <001901c92b4a$217b9010$ad00a8c0@Morris1>

Hi all,

I'm using a Trimble Lassen IQ receiver for a Shera style GPSDO. That part 
works OK but I would also like to get serial data from the receiver's output 
port #2.

The receiver seems to respond to commands sent to port #1 but the desired 
outputs don't seem to appear.

Specifically I want to get two NMEA messages, GGA and ZDA, or alternatively 
the TAIP TM timing message. No matter how I instruct the receiver I don't 
see two NMEA messages, just the first one on the list I've sent to the 
receiver. The TAIP doen't seem to work at all.

Am I missing something here? Has anyone had any success with this device?

Thanks,

Morris



From smace at intt.net  Sat Oct 11 00:11:26 2008
From: smace at intt.net (Scott Mace)
Date: Fri, 10 Oct 2008 23:11:26 -0500
Subject: [time-nuts] BC637PCI
Message-ID: <48F0276E.7040106@intt.net>

Has anyone "upgraded" the oscillator on an older Datum BC637PCI card to
the MTI crystal?  Is it as simple as changing the crystal and adjusting the
osc gain?

	Scott


From rdarlington at gmail.com  Sat Oct 11 00:58:47 2008
From: rdarlington at gmail.com (Robert Darlington)
Date: Fri, 10 Oct 2008 22:58:47 -0600
Subject: [time-nuts] Lassen IQ receiver
In-Reply-To: <001901c92b4a$217b9010$ad00a8c0@Morris1>
References: <001901c92b4a$217b9010$ad00a8c0@Morris1>
Message-ID: <b3bd5fcb0810102158v4bb1f1e1u7c85ddf21ac51478@mail.gmail.com>

I use them for non-time keeping things.  You need to use the configuration
tool to configure the ports so that they both spit out NMEA, and the
particular NMEA strings you want to see, and then save the configuration.
Otherwise you get NMEA out of one port and the Trimble binary format out of
the other.  Do you have a copy of the software?  You can find it here:

http://www.trimble.com/embeddedsystems/lasseniq.aspx?dtID=support

Also, make sure you have the IQ and not the SQ.  The SQ only has one port
but is otherwise pin compatible.

On Fri, Oct 10, 2008 at 8:36 PM, Morris Odell <vilgotch at bigpond.net.au>wrote:

> Hi all,
>
> I'm using a Trimble Lassen IQ receiver for a Shera style GPSDO. That part
> works OK but I would also like to get serial data from the receiver's
> output
> port #2.
>
> The receiver seems to respond to commands sent to port #1 but the desired
> outputs don't seem to appear.
>
> Specifically I want to get two NMEA messages, GGA and ZDA, or alternatively
> the TAIP TM timing message. No matter how I instruct the receiver I don't
> see two NMEA messages, just the first one on the list I've sent to the
> receiver. The TAIP doen't seem to work at all.
>
> Am I missing something here? Has anyone had any success with this device?
>
> Thanks,
>
> Morris
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

From rdarlington at gmail.com  Sat Oct 11 01:06:47 2008
From: rdarlington at gmail.com (Robert Darlington)
Date: Fri, 10 Oct 2008 23:06:47 -0600
Subject: [time-nuts] Lassen IQ receiver
In-Reply-To: <001901c92b4a$217b9010$ad00a8c0@Morris1>
References: <001901c92b4a$217b9010$ad00a8c0@Morris1>
Message-ID: <b3bd5fcb0810102206u5f872877x67ff4dcf6b91095e@mail.gmail.com>

Looking more closely at the software list, I don't see the utility that I
use.  Whatever it is, it's a DOS based thing or is at least a shell ap with
just text.  I'll dig up the zip file at work when I'm in the office over the
weekend and get it over to you if I still have it.  I've used it
successfully to configure both ports to dump NMEA with varying output
strings.

-Bob

On Fri, Oct 10, 2008 at 8:36 PM, Morris Odell <vilgotch at bigpond.net.au>wrote:

> Hi all,
>
> I'm using a Trimble Lassen IQ receiver for a Shera style GPSDO. That part
> works OK but I would also like to get serial data from the receiver's
> output
> port #2.
>
> The receiver seems to respond to commands sent to port #1 but the desired
> outputs don't seem to appear.
>
> Specifically I want to get two NMEA messages, GGA and ZDA, or alternatively
> the TAIP TM timing message. No matter how I instruct the receiver I don't
> see two NMEA messages, just the first one on the list I've sent to the
> receiver. The TAIP doen't seem to work at all.
>
> Am I missing something here? Has anyone had any success with this device?
>
> Thanks,
>
> Morris
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

From vilgotch at bigpond.net.au  Sat Oct 11 02:12:00 2008
From: vilgotch at bigpond.net.au (Morris Odell)
Date: Sat, 11 Oct 2008 17:12:00 +1100
Subject: [time-nuts] Lassen IQ receiver
References: <mailman.403.1223701616.2205.time-nuts@febo.com>
Message-ID: <000c01c92b68$45cc2650$ad00a8c0@Morris1>

Thanks for the reply Bob!

Does this mean it's not possible to get two alternating NMEA messages from 
the same port? I have all the Trimble (IQ_chat and IQ_monitor) utilities and 
use port 1 to communicate with a PC using TSIP. I have port 2 connected to a 
microcontroller and I want to get both strings alternating with each other 
so I can translate them into a different serial code for a particular 
application. Alternatively the TAIP message TM has all the info I need in 
one sentence, but I can't seem to make it appear :-(

It's definitely an IQ not a SQ.

Thanks,

Morris


> From: "Robert Darlington" <rdarlington at gmail.com>

> I use them for non-time keeping things.  You need to use the configuration
> tool to configure the ports so that they both spit out NMEA, and the
> particular NMEA strings you want to see, and then save the configuration.
> Otherwise you get NMEA out of one port and the Trimble binary format out 
> of
> the other.  Do you have a copy of the software?  You can find it here:
>
> http://www.trimble.com/embeddedsystems/lasseniq.aspx?dtID=support
>
> Also, make sure you have the IQ and not the SQ.  The SQ only has one port
> but is otherwise pin compatible.
>
> On Fri, Oct 10, 2008 at 8:36 PM, Morris Odell 
> <vilgotch at bigpond.net.au>wrote:
>
>> Hi all,
>>
>> I'm using a Trimble Lassen IQ receiver for a Shera style GPSDO. That part
>> works OK but I would also like to get serial data from the receiver's
>> output
>> port #2.
>>
>> The receiver seems to respond to commands sent to port #1 but the desired
>> outputs don't seem to appear.
>>
>> Specifically I want to get two NMEA messages, GGA and ZDA, or 
>> alternatively
>> the TAIP TM timing message. No matter how I instruct the receiver I don't
>> see two NMEA messages, just the first one on the list I've sent to the
>> receiver. The TAIP doen't seem to work at all.
>>
>> Am I missing something here? Has anyone had any success with this device?
>>
>> Thanks,
>>
>> Morris
>>
>>
>
> Looking more closely at the software list, I don't see the utility that I
> use.  Whatever it is, it's a DOS based thing or is at least a shell ap 
> with
> just text.  I'll dig up the zip file at work when I'm in the office over 
> the
> weekend and get it over to you if I still have it.  I've used it
> successfully to configure both ports to dump NMEA with varying output
> strings.
>
> -Bob



From hmurray at megapathdsl.net  Sat Oct 11 02:20:20 2008
From: hmurray at megapathdsl.net (Hal Murray)
Date: Fri, 10 Oct 2008 23:20:20 -0700
Subject: [time-nuts] Sulzer Labs D-5 oscillator
In-Reply-To: Message from "Rob Kimberley" <rk@timing-consultants.com> of "Fri,
	10 Oct 2008 08:52:54 BST." <995765D00C9A462CAED3D7B3FE1865C7@Robin> 
Message-ID: <20081011062021.61D43BCD5@ip-64-139-1-69.sjc.megapath.net>


> One of the advantages of top posting - you can reply to the message
> and ignore the rubbish at the bottom....

Did you forget the smiley?  :)

If the bottom is rubbish, why send it?

Ignoring it only works if everybody knows that the convention is to only 
top-post and not insert anything in the middle.  Otherwise you have to scan 
to make sure there aren't any gems buried in there.

Trimming everything that's not needed for context and inserting your comments 
at the right place makes much more sense to me.


Also, blindly top posting sure doesn't help the signal/noise ratio.  I'm on 
one list full of quote-everything top posers.  It often has long threads.  
Each layer picks up another signature, sometimes a corporate disclaimer, and 
the list's unsubscribe/info block.  I get it in digest mode.  Sometimes it's 
a challenge to find the signal.


-- 
These are my opinions, not necessarily my employer's.  I hate spam.





From rdarlington at gmail.com  Sat Oct 11 02:29:07 2008
From: rdarlington at gmail.com (Robert Darlington)
Date: Sat, 11 Oct 2008 00:29:07 -0600
Subject: [time-nuts] Lassen IQ receiver
In-Reply-To: <000c01c92b68$45cc2650$ad00a8c0@Morris1>
References: <mailman.403.1223701616.2205.time-nuts@febo.com>
	<000c01c92b68$45cc2650$ad00a8c0@Morris1>
Message-ID: <b3bd5fcb0810102329g68abdf73ree6116f41fb50959@mail.gmail.com>

As far as alternating, you'll get the various NMEA strings in the order you
choose (and the strings you choose) once a second.  You won't get one, then
the other, then back to the first.  It'll be several  all at once, and that
block will repeat once a second.  I suppose you could select just the two
you want, but they'd come in on the same data burst, repeating once a
second.

first string
second string
<1 second pause>
first string
second string
<1 second pause>
etc.

I don't know for sure if you can have port 1 setup with a particular set of
NMEA data strings and port 2 setup with a different set.  Assuming you can't
do that (meaning they have to be the same NMEA data), you can probably have
both ports spit out everything you'd need and ignore what you don't need in
software.

-Bob

On Sat, Oct 11, 2008 at 12:12 AM, Morris Odell <vilgotch at bigpond.net.au>wrote:

> Thanks for the reply Bob!
>
> Does this mean it's not possible to get two alternating NMEA messages from
> the same port? I have all the Trimble (IQ_chat and IQ_monitor) utilities
> and
> use port 1 to communicate with a PC using TSIP. I have port 2 connected to
> a
> microcontroller and I want to get both strings alternating with each other
> so I can translate them into a different serial code for a particular
> application. Alternatively the TAIP message TM has all the info I need in
> one sentence, but I can't seem to make it appear :-(
>
> It's definitely an IQ not a SQ.
>
> Thanks,
>
> Morris
>
>
> > From: "Robert Darlington" <rdarlington at gmail.com>
>
> > I use them for non-time keeping things.  You need to use the
> configuration
> > tool to configure the ports so that they both spit out NMEA, and the
> > particular NMEA strings you want to see, and then save the configuration.
> > Otherwise you get NMEA out of one port and the Trimble binary format out
> > of
> > the other.  Do you have a copy of the software?  You can find it here:
> >
> > http://www.trimble.com/embeddedsystems/lasseniq.aspx?dtID=support
> >
> > Also, make sure you have the IQ and not the SQ.  The SQ only has one port
> > but is otherwise pin compatible.
> >
> > On Fri, Oct 10, 2008 at 8:36 PM, Morris Odell
> > <vilgotch at bigpond.net.au>wrote:
> >
> >> Hi all,
> >>
> >> I'm using a Trimble Lassen IQ receiver for a Shera style GPSDO. That
> part
> >> works OK but I would also like to get serial data from the receiver's
> >> output
> >> port #2.
> >>
> >> The receiver seems to respond to commands sent to port #1 but the
> desired
> >> outputs don't seem to appear.
> >>
> >> Specifically I want to get two NMEA messages, GGA and ZDA, or
> >> alternatively
> >> the TAIP TM timing message. No matter how I instruct the receiver I
> don't
> >> see two NMEA messages, just the first one on the list I've sent to the
> >> receiver. The TAIP doen't seem to work at all.
> >>
> >> Am I missing something here? Has anyone had any success with this
> device?
> >>
> >> Thanks,
> >>
> >> Morris
> >>
> >>
> >
> > Looking more closely at the software list, I don't see the utility that I
> > use.  Whatever it is, it's a DOS based thing or is at least a shell ap
> > with
> > just text.  I'll dig up the zip file at work when I'm in the office over
> > the
> > weekend and get it over to you if I still have it.  I've used it
> > successfully to configure both ports to dump NMEA with varying output
> > strings.
> >
> > -Bob
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

From XDE-L2G3 at myamail.com  Sat Oct 11 02:40:16 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Sat, 11 Oct 2008 02:40:16 -0400
Subject: [time-nuts] Lassen IQ receiver
References: <001901c92b4a$217b9010$ad00a8c0@Morris1>
	<b3bd5fcb0810102158v4bb1f1e1u7c85ddf21ac51478@mail.gmail.com>
Message-ID: <mailman.20.1223707240.2202.time-nuts@febo.com>

  "Robert Darlington" <rdarlington at gmail.com> wrote:

  > I use  them  for  non-time keeping things.  You  need  to  use the
  > configuration tool  to configure the ports so that they  both spit
  > out NMEA,  and  the particular NMEA strings you want  to  see, and
  > then save the configuration.

  > Otherwise you  get  NMEA out of one port  and  the  Trimble binary
  > format out  of the other. Do you have a copy of the  software? You
  > can find it here:

  >http://www.trimble.com/embeddedsystems/lasseniq.aspx?dtID=support

  > Also, make  sure you have the IQ and not the SQ. The  SQ  only has
  > one port but is otherwise pin compatible.

  Robert,

  These units look interesting. Do you mind if I ask some questions?

  1. What kind of non-time keeping uses have you found for them?

  2. How  well do they work indoors? Do you have to be near  a window?
  What about inside a multi-story building?

  3. How well do they handle constellation changes? Is there an abrupt
  shift in position?

  4. Have you ever taken the shield off and looked inside? If  so, can
  you see the crystal oscillator and tell whether it is a bare crystal
  or a complete oscillator module?

  5. How  much  do  they  cost? Do you know  of  any  others  that are
  cheaper?

  Thanks for your help!

  Best Regards,

  Mike Monett


From rk at timing-consultants.com  Sat Oct 11 03:06:09 2008
From: rk at timing-consultants.com (Rob Kimberley)
Date: Sat, 11 Oct 2008 08:06:09 +0100
Subject: [time-nuts] Sulzer Labs D-5 oscillator
In-Reply-To: <20081011062021.61D43BCD5@ip-64-139-1-69.sjc.megapath.net>
References: Message from "Rob Kimberley" <rk@timing-consultants.com> of "Fri,
	10 Oct 2008 08:52:54 BST." <995765D00C9A462CAED3D7B3FE1865C7@Robin>
	<20081011062021.61D43BCD5@ip-64-139-1-69.sjc.megapath.net>
Message-ID: <F17F40AD76BA4994849B95294A8FEA55@Robin>

The smiley (humour) was implied..

I didn't mean any offence, but have been used to top posting, as business
email (that's what I originally got my email for originally back in the mid
90's) was all (and still is) top posted.

It was only when I ventured into newsgroups that I came across bottom
posting, which to me seemed totally illogical. I've read the pros of bottom
posting (and the cons of top posting), but still can't get my head or my
email prog (Outlook), around it.

Cheers

Rob Kimberley

 

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Hal Murray
Sent: 11 October 2008 07:20
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Sulzer Labs D-5 oscillator


> One of the advantages of top posting - you can reply to the message 
> and ignore the rubbish at the bottom....

Did you forget the smiley?  :)

If the bottom is rubbish, why send it?

Ignoring it only works if everybody knows that the convention is to only
top-post and not insert anything in the middle.  Otherwise you have to scan
to make sure there aren't any gems buried in there.

Trimming everything that's not needed for context and inserting your
comments at the right place makes much more sense to me.


Also, blindly top posting sure doesn't help the signal/noise ratio.  I'm on 
one list full of quote-everything top posers.  It often has long threads.  
Each layer picks up another signature, sometimes a corporate disclaimer, and

the list's unsubscribe/info block.  I get it in digest mode.  Sometimes it's

a challenge to find the signal.


-- 
These are my opinions, not necessarily my employer's.  I hate spam.




_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



From df6jb at ulrich-bangert.de  Sat Oct 11 04:17:40 2008
From: df6jb at ulrich-bangert.de (Ulrich Bangert)
Date: Sat, 11 Oct 2008 10:17:40 +0200
Subject: [time-nuts] PLOTTER & EZGPIB
In-Reply-To: <11567.33191.qm@web81803.mail.mud.yahoo.com>
Message-ID: <19F0B668D6544CA38E21DA75586F1C70@athlon>

Don,

basically my understanding is that every application communicates with
the GPIB hardware itself (may it be a plug in card, a usb interface or a
network based device) not DIRECT but by means of drivers % dlls. The
sense of it all is to make the application more or less independend from
the used GPIB hardware. 

I have a feedback that a script that I have written here and used with a
NI GPIB pci card run without any changes on a different system with a NI
USB GPIB adapter. So there is hope the same holds true for network GPIB
adapter. Perhaps it is you to make the proof?

Regarding VISA: What is built into EZGPIB is the very basic VISA stuff
but NOT an complete implementation. If you do already have VISA based
applications check them out whether the used commands are available in
EZGPIB.

My suggestion is that you just give it a try. With a basic understanding
about how to talk with the devices connected to the bus it should be a
matter of minutes to perform some tests.

Best regards
Ulrich 

> -----Urspr?ngliche Nachricht-----
> Von: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] Im Auftrag von Don @ True-Cal
> Gesendet: Freitag, 10. Oktober 2008 22:03
> An: Discussion of precise time and frequency measurement
> Betreff: Re: [time-nuts] PLOTTER & EZGPIB
> 
> 
> Ulrich,
> 
> I have been wanting to try your EZGPIB to control and capture 
> data from various instruments I run in my lab. My GPIB bus 
> typically has 3-6 instruments connected and I currently use 
> the NI GPIB-ENET/100 as a LAN bridge to any one of several?
> windows based computers. Ocassionally, I also use the?NI 
> GPIB-USB-A connected to a single instrument. In either case, 
> I use the NI drivers and NI-488.2 ver 2.1 on WinXP. My 
> control applications to date have been limited to Agilent VEE 
> Pro along with the Agilent IO library suite. Can you comment 
> on any known problems or issues I might encounter using 
> EZGPIB with the above hardware or VISA API configuration/s. 
> The instruments I may have on the bus are: SR620 HP 53181A HP 
> 5372A HP 3457A HP 8903B Keithley 2002
> 
> Thanks...
> Don
> 
> 
> ----- Original Message ----
> From: Ulrich Bangert <df6jb at ulrich-bangert.de>
> To: Time nuts <time-nuts at febo.com>
> Sent: Friday, October 10, 2008 3:11:19 AM
> Subject: [time-nuts] PLOTTER & EZGPIB
> 
> Gentlemen,
> 
> new versions of PLOTTER and EZGPIB are available. Some bugs 
> concerning the search for Prologix serial & network 
> controllers have been removed and the possibility has been 
> included to log the messages from the debug window into a file.
> 
> PLOTTER now can compute the mean and the SD of a series only 
> on the part of the series that is displayed, i.e. you can 
> zoom in to parts of the series and compute mean & SD for the 
> displayed part only.
> 
> Enjoy
> 
> Ulrich Bangert
> www.ulrich-bangert.de
> Ortholzer Weg 1
> 27243 Gross Ippener 
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-> bin/mailman/listinfo/time-nuts
> and 
> follow the instructions 
> there. _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-> bin/mailman/listinfo/time-nuts
> and 
> follow the instructions there.
> 



From XDE-L2G3 at myamail.com  Sat Oct 11 04:43:17 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Sat, 11 Oct 2008 04:43:17 -0400
Subject: [time-nuts] Sulzer Labs D-5 oscillator
References: <rk@timing-consultants.com>
	<995765D00C9A462CAED3D7B3FE1865C7@Robin>
	<20081011062021.61D43BCD5@ip-64-139-1-69.sjc.megapath.net>
	<F17F40AD76BA4994849B95294A8FEA55@Robin>
Message-ID: <mailman.21.1223714631.2202.time-nuts@febo.com>

  "Rob Kimberley" <rk at timing-consultants.com> wrote:

  > The smiley (humour) was implied.

  > I didn't  mean any offence, but have been used to top  posting, as
  > business email  (that's  what   I   originally  got  my  email for
  > originally back  in  the  mid 90's) was  all  (and  still  is) top
  > posted.

  > It was  only  when I ventured into newsgroups that  I  came across
  > bottom posting,  which to me seemed totally  illogical.  I've read
  > the pros  of  bottom posting (and the cons  of  top  posting), but
  > still can't get my head or my email prog (Outlook), around it.

  >  Cheers

  >  Rob Kimberley

  There is a very big difference between a business email and a forum.

  A business email is usually between two people and concerns only one
  subject. The  exchange  is  usually  very  short,  perhaps  a single
  question and  a  single reply. In these situations,  top  posting is
  probably the easiest method.

  A forum is completely different. There may be many  people involved,
  but unless  they  respond  to a post, you  never  know  if  they are
  present. The  discussion can involve several different  issues, each
  with their  own  thread. New threads can appear  and  take  over the
  entire conversation, or quickly disappear. A discussion can continue
  for a very long time and involve many people.

  In this  situation,  top  posting is  very  inconsiderate.  You have
  already heard all the reasons.

  If your email client is to blame, perhaps it should be replaced with
  one more  suitable. Pimmy is an excellent client, and you  can still
  get version 3.5, the last free one here:

  http://www.321download.com/LastFreeware/page28.html

  Pimmy is  designed  to handle an unlimited number  of  mailboxes and
  accounts. You  can get disposable email addresses from  a  number of
  sites. I have found KasMail is the best:

  http://www.kasmail.com/

  KasMail is  free  and allows you to have up  to  25  different email
  addresses. You can use different ones for eBay, PayPal, and  each of
  your bank  accounts. This helps increase security,  since  you never
  use these  for  anything else. This reduces the  opportunity  for ID
  theft.

  You can  use  some  for typical web sites that  won't  allow  you to
  proceed without an email address. However, these can often be stolen
  and end  up  on a spammer's list. Once there,  it  is  impossible to
  remove them.

  You are  now  vulnerable  to all kinds  of  malware  hidden  in html
  messages. These  use  GIF's, JPEG's, PDf,  IFRAMES,  scripts, Visual
  Basic, and  other  methods  to  hijack  your  system.  Once  in, the
  criminals can  do  anything  they want.  They  can  steal  your bank
  account and  credit  card usernames and  passwords,  and  drain your
  accounts. They can turn your computer into a zombie, sending spam to
  other victims.  You  can end up with numerous  malware  programs all
  fighting for  control.  This can slow down your  computer  and cause
  serious crashes.

  The answer  is to simply dispose of the bad email address and  get a
  new one.

  Following this simple rule, I have virtually eliminated all  spam. I
  now may get one spam every month or two. This is a  huge improvement
  from the hundreds or thousands I used to get.

  One more  thing. Most email clients will execute programs  hidden in
  email, or downloaded from a web site.

  Pimmy will not execute programs. It won't even render html. It won't
  download anything from external sites. So there is no way you can be
  infected by incoming malware hidden in an email message.

  And, of course, Pimmy will let you bottom post:)

  Best Regards,

  Mike Monett


From sar10538 at gmail.com  Sat Oct 11 05:18:01 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Sat, 11 Oct 2008 22:18:01 +1300
Subject: [time-nuts] Sulzer Labs D-5 oscillator
In-Reply-To: <E1Koa4m-0006To-CA@febo.com>
References: <rk@timing-consultants.com>
	<995765D00C9A462CAED3D7B3FE1865C7@Robin>
	<20081011062021.61D43BCD5@ip-64-139-1-69.sjc.megapath.net>
	<F17F40AD76BA4994849B95294A8FEA55@Robin> <E1Koa4m-0006To-CA@febo.com>
Message-ID: <1231b6a80810110218v699ec251ke1cff6779857ad65@mail.gmail.com>

2008/10/11 Mike Monett <XDE-L2G3 at myamail.com>:
>  "Rob Kimberley" <rk at timing-consultants.com> wrote:
>
>  > The smiley (humour) was implied.
>
>  > I didn't  mean any offence, but have been used to top  posting, as
>  > business email  (that's  what   I   originally  got  my  email for
>  > originally back  in  the  mid 90's) was  all  (and  still  is) top
>  > posted.
>
>  > It was  only  when I ventured into newsgroups that  I  came across
>  > bottom posting,  which to me seemed totally  illogical.  I've read
>  > the pros  of  bottom posting (and the cons  of  top  posting), but
>  > still can't get my head or my email prog (Outlook), around it.
>
>  >  Cheers
>
>  >  Rob Kimberley
>
>  There is a very big difference between a business email and a forum.
>
>  A business email is usually between two people and concerns only one
>  subject. The  exchange  is  usually  very  short,  perhaps  a single
>  question and  a  single reply. In these situations,  top  posting is
>  probably the easiest method.
>
>  A forum is completely different. There may be many  people involved,
>  but unless  they  respond  to a post, you  never  know  if  they are
>  present. The  discussion can involve several different  issues, each
>  with their  own  thread. New threads can appear  and  take  over the
>  entire conversation, or quickly disappear. A discussion can continue
>  for a very long time and involve many people.
>
>  In this  situation,  top  posting is  very  inconsiderate.  You have
>  already heard all the reasons.
>
>  If your email client is to blame, perhaps it should be replaced with
>  one more  suitable. Pimmy is an excellent client, and you  can still
>  get version 3.5, the last free one here:
>
>  http://www.321download.com/LastFreeware/page28.html
>
>  Pimmy is  designed  to handle an unlimited number  of  mailboxes and
>  accounts. You  can get disposable email addresses from  a  number of
>  sites. I have found KasMail is the best:
>
>  http://www.kasmail.com/
>
>  KasMail is  free  and allows you to have up  to  25  different email
>  addresses. You can use different ones for eBay, PayPal, and  each of
>  your bank  accounts. This helps increase security,  since  you never
>  use these  for  anything else. This reduces the  opportunity  for ID
>  theft.
>
>  You can  use  some  for typical web sites that  won't  allow  you to
>  proceed without an email address. However, these can often be stolen
>  and end  up  on a spammer's list. Once there,  it  is  impossible to
>  remove them.
>
>  You are  now  vulnerable  to all kinds  of  malware  hidden  in html
>  messages. These  use  GIF's, JPEG's, PDf,  IFRAMES,  scripts, Visual
>  Basic, and  other  methods  to  hijack  your  system.  Once  in, the
>  criminals can  do  anything  they want.  They  can  steal  your bank
>  account and  credit  card usernames and  passwords,  and  drain your
>  accounts. They can turn your computer into a zombie, sending spam to
>  other victims.  You  can end up with numerous  malware  programs all
>  fighting for  control.  This can slow down your  computer  and cause
>  serious crashes.
>
>  The answer  is to simply dispose of the bad email address and  get a
>  new one.
>
>  Following this simple rule, I have virtually eliminated all  spam. I
>  now may get one spam every month or two. This is a  huge improvement
>  from the hundreds or thousands I used to get.
>
>  One more  thing. Most email clients will execute programs  hidden in
>  email, or downloaded from a web site.
>
>  Pimmy will not execute programs. It won't even render html. It won't
>  download anything from external sites. So there is no way you can be
>  infected by incoming malware hidden in an email message.
>
>  And, of course, Pimmy will let you bottom post:)
>
>  Best Regards,
>
>  Mike Monett
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

Or you can use Linux and not worry about any of this :)

And I personally think that Rob has been unfairly taken to task over a
comment about the verbiage added to emails sent from some corporate
systems which add huge disclaimers to the bottom of each message. I
took his reply as a friendly jibe to my previous light-hearted comment
on this.

73
Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From XDE-L2G3 at myamail.com  Sat Oct 11 05:46:38 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Sat, 11 Oct 2008 05:46:38 -0400
Subject: [time-nuts] Sulzer Labs D-5 oscillator
References: <rk@timing-consultants.com>
	<995765D00C9A462CAED3D7B3FE1865C7@Robin>
	<20081011062021.61D43BCD5@ip-64-139-1-69.sjc.megapath.net>
	<F17F40AD76BA4994849B95294A8FEA55@Robin>
	<E1Koa4m-0006To-CA@febo.com>
	<1231b6a80810110218v699ec251ke1cff6779857ad65@mail.gmail.com>
Message-ID: <mailman.22.1223718427.2202.time-nuts@febo.com>

  "Steve Rooke" <sar10538 at gmail.com> wrote:

  > Or you can use Linux and not worry about any of this :)

  > And I  personally think that Rob has been unfairly  taken  to task
  > over a  comment about the verbiage added to emails sent  from some
  > corporate systems which add huge disclaimers to the bottom of each
  > message. I  took  his  reply as a  friendly  jibe  to  my previous
  > light-hearted comment on this.

  >73
  >Steve

  >Steve Rooke - ZL3TUV & G8KVD
  >Omnium finis imminet

  Steve,

  I'm in  the  process  of switching over  to  Ubuntu,  and  I already
  checked - Wine handles Pimmy.

  Does linux have an email client that handles multiple accounts?

  BTW, my  reason for switching will probably affect more people  in a
  couple of  years.  I am running Win98, and recently  bought  two new
  Asus motherboards.  They no longer have drivers for Win98,  but they
  do have drivers for Ubuntu and several other distros.

  WinXP will  expire  soon,  and  VISTA is  a  disaster.  There  is no
  guarantee the  next  release  will   be  any  better.  And  you will
  eventually need  a new motherboard or two, so the handwriting  is on
  the wall.

  Best Regards,

  Mike Monett


From wb6bnq at cox.net  Sat Oct 11 06:09:35 2008
From: wb6bnq at cox.net (WB6BNQ)
Date: Sat, 11 Oct 2008 03:09:35 -0700
Subject: [time-nuts] Sulzer Labs D-5 oscillator
References: <rk@timing-consultants.com>
	<995765D00C9A462CAED3D7B3FE1865C7@Robin>
	<20081011062021.61D43BCD5@ip-64-139-1-69.sjc.megapath.net>
	<F17F40AD76BA4994849B95294A8FEA55@Robin> <E1Koa4m-0006To-2D@febo.com>
Message-ID: <48F07B5F.8816F579@cox.net>

   Mike Monett wrote:

       There is a very big difference between a business email and a
     forum.

       A business email is usually between two people and concerns only
     one
       subject. The  exchange  is  usually  very  short,  perhaps  a
     single
       question and  a  single reply. In these situations,  top  posting
     is
       probably the easiest method.

       A forum is completely different. <snip>

       In this  situation,  top  posting is  very  inconsiderate.  You
     have
       already heard all the reasons.

       Best Regards,

       Mike Monett

   Mike,

   Just for your pleasure I am posting at the bottom.  Hmmmm did I get
   that right ?

   While there is an issue with TOP/BOTTOM posting styles, I think the
   original comment was referring to all the CRAP people include after
   they "sign" at the bottom of their post.  Some have [presumably] a cute
   little saying, others are totally paranoid, and the original post had
   so much crap that, besides wasting space, I did not bother to read it.

   People or companies' use that space to post a form of denial or an
   apology.  Today, with such a litigious world, maybe it has some value.
   Just think, you do not see the U.S. Post Office putting such verbiage
   on the mail we give them to carry around.

   The only stuff that makes sense after you "sign off" would be a phone
   number or snail mail address, or perhaps a web site URL.  One or two
   short lines, after that it is going to far.  That my view and I am
   sticking to it !

   As for the TOP/BOTTOM thing, I find it hard to read an email from the
   bottom up to properly follow the action, especially with the extraneous
   stuff.  However, it is a pain, at times, to go the other way too.  I
   really hate it when people make a reply with no reference to what they
   were referring to.  You know, a blank email with just a comment like
   "Yes I agree."  I get those and the subject line gives no clue either.

   The real answer is people are getting sloppy and forgetting how to
   properly write, whether it is a formal letter or an informal note.  An
   Email is a letter !  All the "do - dad" shorts for smiling and such
   (none of which I have learned) allow people to forget how to describe,
   more accurately with words, their ideas and feelings.

   Bill....WB6BNQ

From rexa at sonic.net  Sat Oct 11 06:26:01 2008
From: rexa at sonic.net (Rex)
Date: Sat, 11 Oct 2008 03:26:01 -0700
Subject: [time-nuts] Sulzer Labs D-5 oscillator
In-Reply-To: <E1Koa4m-0006To-5w@febo.com>
References: <rk@timing-consultants.com>	<995765D00C9A462CAED3D7B3FE1865C7@Robin>	<20081011062021.61D43BCD5@ip-64-139-1-69.sjc.megapath.net>	<F17F40AD76BA4994849B95294A8FEA55@Robin>
	<E1Koa4m-0006To-5w@febo.com>
Message-ID: <48F07F39.2080108@sonic.net>

This group seems pretty flexible about -- top -- mid -- or bottom -- 
posting.

Don't see any reason to lecture this group about how they might want to 
communicate.
I never paid attention about how it was being done, but it all seems to 
work here. I never can remember having any thought about bad form.

Mike Monett wrote:
>   There is a very big difference between a business email and a forum.
>
>   
...
Wow, that was a long message. Imagine how far we would have to scroll if 
I hadn't deleted it. -- And if I felt obligated to take the effort to 
bottom post my reply.
>   
>   Best Regards,
>
>   Mike Monett
>
>   
So there are points of view about posting. Feel free to continue to 
contribute, but I never saw a lecture about netiquette here before, and 
don't see the need.



From vilgotch at bigpond.net.au  Sat Oct 11 07:51:29 2008
From: vilgotch at bigpond.net.au (Morris Odell)
Date: Sat, 11 Oct 2008 22:51:29 +1100
Subject: [time-nuts] Lassen IQ receiver
References: <mailman.406.1223714630.2205.time-nuts@febo.com>
Message-ID: <001d01c92b97$b28beb20$ad00a8c0@Morris1>

Thanks again Bob,

Yes, that's what I thought it would do, but It doesn't seem to be so. My 
micro is programmed to identify the beginning of an NMEA string by the $ 
character and there's only one per sec. Maybe the second string is 
concatenated onto the first one without the dollar symbol.

Having said all that, in the time between my original post and this one I 
managed to get the TAIP output working and the micro to recognise it so I'm 
a happy man :-)

Morris

> Date: Sat, 11 Oct 2008 00:29:07 -0600
> From: "Robert Darlington" <rdarlington at gmail.com>
> Subject: Re: [time-nuts] Lassen IQ receiver
>>
> As far as alternating, you'll get the various NMEA strings in the order 
> you
> choose (and the strings you choose) once a second.  You won't get one, 
> then
> the other, then back to the first.  It'll be several  all at once, and 
> that
> block will repeat once a second.  I suppose you could select just the two
> you want, but they'd come in on the same data burst, repeating once a
> second.
>
> first string
> second string
> <1 second pause>
> first string
> second string
> <1 second pause>
> etc.
>
> I don't know for sure if you can have port 1 setup with a particular set 
> of
> NMEA data strings and port 2 setup with a different set.  Assuming you 
> can't
> do that (meaning they have to be the same NMEA data), you can probably 
> have
> both ports spit out everything you'd need and ignore what you don't need 
> in
> software.
>
> -Bob



From vilgotch at bigpond.net.au  Sat Oct 11 08:08:33 2008
From: vilgotch at bigpond.net.au (Morris Odell)
Date: Sat, 11 Oct 2008 23:08:33 +1100
Subject: [time-nuts] Lassen IQ receiver
References: <mailman.406.1223714630.2205.time-nuts@febo.com>
Message-ID: <002201c92b9a$14f68cf0$ad00a8c0@Morris1>

Hi Mike,

The Lassen IQ is a little PCB mounted 12 channel receiver about half the 
size of a matchbox, which is intended for OEM applications. It's not easy to 
open to see what's inside. It uses tiny surface mount connectors to get 
signals in and out but there's no access to the oscillator if you want to 
use an external osc.  It doesn't have a built in antenna so the performance 
depends on the external antenna connected to it. It seems to handle 
constellation changes quite well as far as I can see. The application info 
says it can be used for navigation as well as timekeeping.

It has 2 serial ports as well as a 1 pps output. One serial port is used to 
control and read it using Trimble's TSIP binary protocol. There is free DOS 
and Windows software available from Trimble to do this. The other port can 
be configured to use TSIP, NMEA or Trimble's own ASCII protocol called TAIP.

I paid AU$70 about 2 years ago, which at the time was equivalent to about 
US$60. You could probably do better these days. I bought a bunch of old 6 
channel VP Oncore receivers about a year ago on ebay for AU12 each. They are 
ideal for timing aplications and clocks.

HTH,

Morris

>
>  These units look interesting. Do you mind if I ask some questions?
>
>  1. What kind of non-time keeping uses have you found for them?
>
>  2. How  well do they work indoors? Do you have to be near  a window?
>  What about inside a multi-story building?
>
>  3. How well do they handle constellation changes? Is there an abrupt
>  shift in position?
>
>  4. Have you ever taken the shield off and looked inside? If  so, can
>  you see the crystal oscillator and tell whether it is a bare crystal
>  or a complete oscillator module?
>
>  5. How  much  do  they  cost? Do you know  of  any  others  that are
>  cheaper?
>
>  Thanks for your help!
>
>  Best Regards,
>
>  Mike Monett
>
> 


From jim77742 at gmail.com  Sat Oct 11 08:10:52 2008
From: jim77742 at gmail.com (Jim Palfreyman)
Date: Sat, 11 Oct 2008 23:10:52 +1100
Subject: [time-nuts] COMPLETELY off topic - but I know you'll read it anyway.
Message-ID: <f616e0f80810110510p4e8e1a1fw932acf8093cc38ea@mail.gmail.com>

OK I have an interesting but simple problem that has nothing to do with
time. But I'm sure someone on this list will know. And besides I can't be
stuffed finding another list with such a good S/N ratio.

In my spare time I play in a band.

I have a 1000W amplifier that can be either two 500W stereo channels or a
single 1000W mono running in "bridged" mode. (Basically one channel
amplifies the upper part of the sine curve and the other the lower.)

The amp can drive speakers down to 4 ohms.

I have two 8 ohm speakers.

The source is mono.

Do I run each 8 ohm speaker on its own 500W channel?

or

Do I run in bridged mode and put the two speakers in parallel onto the 1000W
amplifier?

Any takers?

Regards,

Jim

From phk at phk.freebsd.dk  Sat Oct 11 08:16:26 2008
From: phk at phk.freebsd.dk (Poul-Henning Kamp)
Date: Sat, 11 Oct 2008 12:16:26 +0000
Subject: [time-nuts] COMPLETELY off topic - but I know you'll read it
	anyway.
In-Reply-To: Your message of "Sat, 11 Oct 2008 23:10:52 +1100."
	<f616e0f80810110510p4e8e1a1fw932acf8093cc38ea@mail.gmail.com> 
Message-ID: <32205.1223727386@critter.freebsd.dk>

In message <f616e0f80810110510p4e8e1a1fw932acf8093cc38ea at mail.gmail.com>, "Jim 
Palfreyman" writes:

>Do I run each 8 ohm speaker on its own 500W channel?
>
>or
>
>Do I run in bridged mode and put the two speakers in parallel onto the 1000W
>amplifier?

Unless the two speakers are _very_ identical, including length and type
of cabling from the amplifier, I will recommend against running them in
parallel.

As former sound technician I will also say this: run them on separate
channels, if you loose one channel, you don't loose your sound entirely.

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.


From cfharris at erols.com  Sat Oct 11 08:16:47 2008
From: cfharris at erols.com (Chuck Harris)
Date: Sat, 11 Oct 2008 08:16:47 -0400
Subject: [time-nuts] Sulzer Labs D-5 oscillator
In-Reply-To: <E1Kob40-0007Bt-0h@febo.com>
References: <rk@timing-consultants.com>	<995765D00C9A462CAED3D7B3FE1865C7@Robin>	<20081011062021.61D43BCD5@ip-64-139-1-69.sjc.megapath.net>	<F17F40AD76BA4994849B95294A8FEA55@Robin>	<E1Koa4m-0006To-CA@febo.com>	<1231b6a80810110218v699ec251ke1cff6779857ad65@mail.gmail.com>
	<E1Kob40-0007Bt-0h@febo.com>
Message-ID: <48F0992F.9020606@erols.com>

Mike Monett wrote:
>   "Steve Rooke" <sar10538 at gmail.com> wrote:
> 
>   > Or you can use Linux and not worry about any of this :)
> 
>   > And I  personally think that Rob has been unfairly  taken  to task
>   > over a  comment about the verbiage added to emails sent  from some
>   > corporate systems which add huge disclaimers to the bottom of each
>   > message. I  took  his  reply as a  friendly  jibe  to  my previous
>   > light-hearted comment on this.
> 
>   >73
>   >Steve
> 
>   >Steve Rooke - ZL3TUV & G8KVD
>   >Omnium finis imminet
> 
>   Steve,
> 
>   I'm in  the  process  of switching over  to  Ubuntu,  and  I already
>   checked - Wine handles Pimmy.
> 
>   Does linux have an email client that handles multiple accounts?

Of course!

If you like an all-in-one browser/email, try seamonkey.  If you want just
mail/news, try thunderbird.  Or pine, or gmail, or kmail, or citadel...


> 
>   BTW, my  reason for switching will probably affect more people  in a
>   couple of  years.  I am running Win98, and recently  bought  two new
>   Asus motherboards.  They no longer have drivers for Win98,  but they
>   do have drivers for Ubuntu and several other distros.

Linux has drivers for just about everything.  You don't have to go to
the manufacturers for the driver very often.

A better reason to change to linux is for reliability.  A nice bonus is
the wide variety of high quality free software that is available.

I have been using linux exclusively for about 12 years now.

-Chuck Harris


From bruce.griffiths at xtra.co.nz  Sat Oct 11 08:24:18 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Sun, 12 Oct 2008 01:24:18 +1300
Subject: [time-nuts] COMPLETELY off topic - but I know you'll read it
 anyway.
In-Reply-To: <f616e0f80810110510p4e8e1a1fw932acf8093cc38ea@mail.gmail.com>
References: <f616e0f80810110510p4e8e1a1fw932acf8093cc38ea@mail.gmail.com>
Message-ID: <48F09AF2.9000103@xtra.co.nz>

Jim Palfreyman wrote:
> OK I have an interesting but simple problem that has nothing to do with
> time. But I'm sure someone on this list will know. And besides I can't be
> stuffed finding another list with such a good S/N ratio.
>
> In my spare time I play in a band.
>
> I have a 1000W amplifier that can be either two 500W stereo channels or a
> single 1000W mono running in "bridged" mode. (Basically one channel
> amplifies the upper part of the sine curve and the other the lower.)
>
>   
Thats not an accurate description of how bridged amplifiers work.
The load is connected between the 2 outputs which are 180 degrees out of 
phase.
This doubles the available voltage swing across the load.
For a given load, this quadruples the power (provided neither of the 
amplifiers goes into current limit).

> The amp can drive speakers down to 4 ohms.
>
>   
4 ohms in bridged mode?
Or 4 ohms in single ended mode?
> I have two 8 ohm speakers.
>
> The source is mono.
>
> Do I run each 8 ohm speaker on its own 500W channel?
>
> or
>
> Do I run in bridged mode and put the two speakers in parallel onto the 1000W
> amplifier?
>
> Any takers?
>
> Regards,
>
> Jim
>   

Bruce


From didier at cox.net  Sat Oct 11 08:30:00 2008
From: didier at cox.net (Didier Juges)
Date: Sat, 11 Oct 2008 07:30:00 -0500
Subject: [time-nuts] Sulzer Labs D-5 oscillator
In-Reply-To: <48F07F39.2080108@sonic.net>
References: <rk@timing-consultants.com>	<995765D00C9A462CAED3D7B3FE1865C7@Robin>	<20081011062021.61D43BCD5@ip-64-139-1-69.sjc.megapath.net>	<F17F40AD76BA4994849B95294A8FEA55@Robin><E1Koa4m-0006To-5w@febo.com>
	<48F07F39.2080108@sonic.net>
Message-ID: <BC5BEF0BC7EA4DF49DB86533E125C2FA@didierhp>

It never ceases to amaze me that this group is by far the highest S/N ratio
group that I belong to, populated by a vast majority of people who are
widely smarter than I am, and yet it seems many of these people can't figure
a thread because it may have mixed top-post and bottom-post and whatnot. 

Get over it, you won't fix it. 

Personally, I respect everyone's opinion, but I have given up in trying to
have the world see things my way, so I try to remain flexible. It's good for
the brain anyhow.

When I read mail on my Blackberry, it is EXTREMELY aggravating to have to
scroll to the bottom of even a short thread to see the response, so that's
one case where top posting is WIDELY preferred, and when I read mail on my
Blackberry, I think bottom posters are VERY inconsiderate to me. And no,
your favorite email client/operating system probably won't run on the
Blackberry. And no, I won't switch to a PDA that runs Linux so you can
bottom post without aggravating me, and no, don't lecture me about the
virtues of Linux, I run 6 Linux machines at the moment (those that actually
have work to do), even though my desktop runs XP Pro.

On the other hand, my friend Bruce always bottom posts, and since his
contributions are so valuable, I try to keep his threads in order and I make
an effort to bottom post on his messages.

Other than that, I do what I feel like is most appropriate. On messages that
are unlikely to add long term value to the archive, like this one, I usually
top post. Then you don't have to scroll all the way down before hitting
"Delete".

Didier

> -----Original Message-----
> From: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Rex
> Sent: Saturday, October 11, 2008 5:26 AM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Sulzer Labs D-5 oscillator
> 
> This group seems pretty flexible about -- top -- mid -- or 
> bottom -- posting.
> 
> Don't see any reason to lecture this group about how they 
> might want to communicate.
> I never paid attention about how it was being done, but it 
> all seems to work here. I never can remember having any 
> thought about bad form.
> 



From didier at cox.net  Sat Oct 11 08:38:45 2008
From: didier at cox.net (Didier Juges)
Date: Sat, 11 Oct 2008 07:38:45 -0500
Subject: [time-nuts] COMPLETELY off topic - but I know you'll read it
	anyway.
In-Reply-To: <48F09AF2.9000103@xtra.co.nz>
References: <f616e0f80810110510p4e8e1a1fw932acf8093cc38ea@mail.gmail.com>
	<48F09AF2.9000103@xtra.co.nz>
Message-ID: <68792EF9B27745D6B8F39E4B34A09D62@didierhp>

 

> -----Original Message-----
> From: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Bruce Griffiths
> Sent: Saturday, October 11, 2008 7:24 AM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] COMPLETELY off topic - but I know 
> you'll read it anyway.
> 
> Jim Palfreyman wrote:
> > OK I have an interesting but simple problem that has nothing to do 
> > with time. But I'm sure someone on this list will know. And 
> > besides I can't be stuffed finding another list with such a 
> > good S/N ratio.
> >
> > In my spare time I play in a band.
> >
> > I have a 1000W amplifier that can be either two 500W stereo 
> > channels or a single 1000W mono running in "bridged" mode. 
> > (Basically one channel amplifies the upper part of the sine 
> > curve and the other the lower.)
> >
> >   

> Thats not an accurate description of how bridged amplifiers work.
> The load is connected between the 2 outputs which are 180 
> degrees out of phase.
> This doubles the available voltage swing across the load.
> For a given load, this quadruples the power (provided neither 
> of the amplifiers goes into current limit).
> 

> > The amp can drive speakers down to 4 ohms.
> >
> >   

> 4 ohms in bridged mode?
> Or 4 ohms in single ended mode?

> > I have two 8 ohm speakers.
> >
> > The source is mono.
> >
> > Do I run each 8 ohm speaker on its own 500W channel?
> >
> > or
> >
> > Do I run in bridged mode and put the two speakers in 
> > parallel onto the 1000W amplifier?
> >
> > Any takers?
> >
> > Regards,
> >
> > Jim
> >   
> 
> Bruce
> 

Jim,


Since your amplifier is specified at 1000W bridged and 2x500W non bridged,
that seems to indicate that the amp would be current limited (otherwise you
could get 200W in bridged mode), so in bridged mode, you are expected to use
speakers with 2ximpedance specified for non-bridged operation.

You say the amplifier can drive speakers down to 4 ohms, but is that the
impedance where it can deliver 500W non-bridged?

If so, you will need 8 ohm impedance to get 1000W bridged. You can't get
there with two 8 ohm speakers, unless you use a transformer.

Since the power is likely to be the same if you bridge the amplifier and put
the speakers in series, or drive each speaker with it's own channel, I would
recommend the second (each speaker on it's own output, non bridged
operation) as it will probably have lower distortion.

Didier



From jherrero at hvsistemas.es  Sat Oct 11 08:38:39 2008
From: jherrero at hvsistemas.es (Javier Herrero)
Date: Sat, 11 Oct 2008 14:38:39 +0200
Subject: [time-nuts] COMPLETELY off topic - but I know you'll read it
 anyway.
In-Reply-To: <f616e0f80810110510p4e8e1a1fw932acf8093cc38ea@mail.gmail.com>
References: <f616e0f80810110510p4e8e1a1fw932acf8093cc38ea@mail.gmail.com>
Message-ID: <48F09E4F.2030907@hvsistemas.es>

If 500W are specified for a 4 ohm load, you will only obtain 250W for 
each channel over a 8 ohm speaker. In bridged mode, it is not true that 
basically one channel drives the upper part of the sine and the other 
the lower: they operate in push-pull, supplying each side of the speaker 
with opposite phases so you will obtain the double peak-to-peak  voltage 
value over the load than in the single ended configuration. Double 
voltage would mean four-times power, so the amplifier surely is not 
rated for the same load in bridged mode than in single-ended two-channel 
mode. If minimum load for each channel is 4 ohm in single-ended mode, 
usually it is 8 ohm for two channels in bridged mode.

So if you have 8 ohm speakers... use it in single ended mode (better 
reliability also, as Poul-Henning pointed), and you will get 250W per 
channel. In brigde mode, you could only put the two speakers in parallel 
if the amplifier is rated for 4 ohm loads in bridged mode.

Regards,

Javier

Jim Palfreyman escribi?:
> OK I have an interesting but simple problem that has nothing to do with
> time. But I'm sure someone on this list will know. And besides I can't be
> stuffed finding another list with such a good S/N ratio.
>
> In my spare time I play in a band.
>
> I have a 1000W amplifier that can be either two 500W stereo channels or a
> single 1000W mono running in "bridged" mode. (Basically one channel
> amplifies the upper part of the sine curve and the other the lower.)
>
> The amp can drive speakers down to 4 ohms.
>
> I have two 8 ohm speakers.
>
> The source is mono.
>
> Do I run each 8 ohm speaker on its own 500W channel?
>
> or
>
> Do I run in bridged mode and put the two speakers in parallel onto the 1000W
> amplifier?
>
> Any takers?
>
> Regards,
>
> Jim
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>

-- 
------------------------------------------------------------------------
Javier Herrero                            EMAIL: jherrero at hvsistemas.com
HV Sistemas S.L.                          PHONE:         +34 949 336 806
Los Charcones, 17A                        FAX:           +34 949 336 792
19170 El Casar - Guadalajara - Spain      WEB: http://www.hvsistemas.com



From jim77742 at gmail.com  Sat Oct 11 08:48:04 2008
From: jim77742 at gmail.com (Jim Palfreyman)
Date: Sat, 11 Oct 2008 23:48:04 +1100
Subject: [time-nuts] COMPLETELY off topic - but I know you'll read it
	anyway.
In-Reply-To: <48F09E4F.2030907@hvsistemas.es>
References: <f616e0f80810110510p4e8e1a1fw932acf8093cc38ea@mail.gmail.com>
	<48F09E4F.2030907@hvsistemas.es>
Message-ID: <f616e0f80810110548j1af03d49r8405421b8d8e0f24@mail.gmail.com>

Thanks folks for your quick replies.

I've dug out the manual and even though the specifications say it can do 4
ohms in bridged mode, there is another statement that says it doesn't
recommend it.

Here is what it says about bridged mode:

"The A channel handles the positive voltage and the B channel becomes the
negative, thus doubling the output voltage swing."

Needless to say, Poul's comment regarding running them as two separate
channels because if one fails I'll have another as a spare is the clincher
for me. Being from an IT background - backup is all important.

Thanks folks!



2008/10/11 Javier Herrero <jherrero at hvsistemas.es>

> If 500W are specified for a 4 ohm load, you will only obtain 250W for
> each channel over a 8 ohm speaker. In bridged mode, it is not true that
> basically one channel drives the upper part of the sine and the other
> the lower: they operate in push-pull, supplying each side of the speaker
> with opposite phases so you will obtain the double peak-to-peak  voltage
> value over the load than in the single ended configuration. Double
> voltage would mean four-times power, so the amplifier surely is not
> rated for the same load in bridged mode than in single-ended two-channel
> mode. If minimum load for each channel is 4 ohm in single-ended mode,
> usually it is 8 ohm for two channels in bridged mode.
>
> So if you have 8 ohm speakers... use it in single ended mode (better
> reliability also, as Poul-Henning pointed), and you will get 250W per
> channel. In brigde mode, you could only put the two speakers in parallel
> if the amplifier is rated for 4 ohm loads in bridged mode.
>
> Regards,
>
> Javier
>
> Jim Palfreyman escribi?:
> > OK I have an interesting but simple problem that has nothing to do with
> > time. But I'm sure someone on this list will know. And besides I can't be
> > stuffed finding another list with such a good S/N ratio.
> >
> > In my spare time I play in a band.
> >
> > I have a 1000W amplifier that can be either two 500W stereo channels or a
> > single 1000W mono running in "bridged" mode. (Basically one channel
> > amplifies the upper part of the sine curve and the other the lower.)
> >
> > The amp can drive speakers down to 4 ohms.
> >
> > I have two 8 ohm speakers.
> >
> > The source is mono.
> >
> > Do I run each 8 ohm speaker on its own 500W channel?
> >
> > or
> >
> > Do I run in bridged mode and put the two speakers in parallel onto the
> 1000W
> > amplifier?
> >
> > Any takers?
> >
> > Regards,
> >
> > Jim
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at febo.com
> > To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
> >
> >
>
> --
> ------------------------------------------------------------------------
> Javier Herrero                            EMAIL: jherrero at hvsistemas.com
> HV Sistemas S.L.                          PHONE:         +34 949 336 806
> Los Charcones, 17A                        FAX:           +34 949 336 792
> 19170 El Casar - Guadalajara - Spain      WEB: http://www.hvsistemas.com
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

From GandalfG8 at aol.com  Sat Oct 11 10:42:49 2008
From: GandalfG8 at aol.com (GandalfG8 at aol.com)
Date: Sat, 11 Oct 2008 10:42:49 EDT
Subject: [time-nuts] BC637PCI
Message-ID: <cd1.3bfd752f.36221569@aol.com>

 
In a message dated 11/10/2008 05:12:11 GMT Daylight Time, smace at intt.net  
writes:

Has  anyone "upgraded" the oscillator on an older Datum BC637PCI card to
the MTI  crystal?  Is it as simple as changing the crystal and adjusting  the
osc gain?



---------
Hi Scott
 
I've not changed the oscillator, but I did look into the possibility and  
also ran a BC637PCI for a while with an external Vectron ovened 10MHz  oscillator.
 
I assume you have the BC637PCI manual?
Appendix A refers to field upgrades, both converting a 635 to 637 by adding  
the GPS module and upgrading to the ovened oscillator.
In both instances a firmware "upgrade" was activated by entering a device  
specific password provided by Datum/Symmetricom. I doubt that option  is still 
longer available even though the necessary firmware changes are  obviously 
already there waiting to be activated.
I suspect, in the case of the oscillator upgrade anyway, some default  
settings including oscillator gain will be all that's changed.
 
When running with an external oscillator I found that loss of power would  
default any settings I had changed so no doubt that's what would happen if you  
upgraded the oscillator without the firmware change.
Page 6-15, in the rev K manual anyway, gives details of the oscillator gain  
adjustment, I found approx 70 seemed reasonable with my Vectron oscillator  
but my BC637PCI, and perhaps others, has some conditioning issues  anyway.
 
The basic onboard oscillator was not very good, apologies for such an  
imprecise statement but I can't find the fairly extensive notes made several  months 
ago, both accuracy and stability were relatively poor measured on an  
HP53132A using a known good Thunderbolt as a reference.
In particular I noticed quite frequent, but seemingly random, jumps in  
output frequency that would then take a little while to recover, a bit like a  fast 
acting automatic gain control with slow recovery time. These jumps  were 
significantly greater than the "normal" variations I observed and  fell outside of 
the unit specification.
 
Using the Vectron oscillator greatly improved things, it was a much better  
oscillator anyway and I was able to observe the significant  improvement in the 
Vectron performance when being conditioned by the  BC637PCI.
However, the frequency jumps still occured albeit with overall performance  
much improved and frequency stability much better and the jumps less than  
before, ie frequency jumps were seemingly reduced in proportion to the better  
accuracy.
Without the jumps I would have been happy with the Vectron performance  but 
didn't feel able to trust the combination without permanent  computer 
monitoring, and still don't know if this was a function of my  BC637PCI or something 
common to all of them.
 
It was interesting to play with, and I'll probably go back to it at some  
time, but I was more concerned then to set up something I could rely on and  
eventually put it to one side.
 
Whilst working with the BC637PCI I did find that I needed both the  BC635PCI 
and BC637PCI software, both offer options the other lacks, and I have  late 
copies of both if you need them.
I also have two manuals, version H from Datum that includes schematics, and  
the fairly similar version K from Symmetricom but without schematics.
 
regards
 
Nigel
GM8PZR
 
 
 



**************   

From frank at timebone.net  Sat Oct 11 10:48:08 2008
From: frank at timebone.net (frank at timebone.net)
Date: Sat, 11 Oct 2008 16:48:08 +0200
Subject: [time-nuts] mailing list policies (formerly Sulzer Labs D-5 osc)
In-Reply-To: <mailman.416.1223727398.2205.time-nuts@febo.com>
References: <mailman.416.1223727398.2205.time-nuts@febo.com>
Message-ID: <20081011144808.99710@gmx.net>

>  humour) was implied.
>  I didn't  mean any offence, but have been used to top  posting, as
>  business email  
>   A forum is completely different. 
>   Pimmy will not execute programs. 
>   and follow the instructions there.
>   Or you can use Linux 
>   Does linux have an email client that handles multiple accounts?
>   WinXP will  expire  soon
>   An Email is a letter ! 
 
Interesting isn't it for the subject of "Sulzer Labs D-5 Oscillator"?
Overall I have found many straight and interesting "conversation" here,
few times I felt a little bored, e.g. by wrong subject entry, 
but overall looks like a matter of working self-teaching.

> So there are points of view about posting. Feel free to continue to 
> contribute, but I never saw a lecture about netiquette here before, and 
> don't see the need.
I agree and
I see this due to the difference between this "mailing list" and a "news-group".

Looking forward to the future of this time-nuts mailing list.
best regards,
Frank
<EOF>


From GandalfG8 at aol.com  Sat Oct 11 10:55:32 2008
From: GandalfG8 at aol.com (GandalfG8 at aol.com)
Date: Sat, 11 Oct 2008 10:55:32 EDT
Subject: [time-nuts] BC637PCI
Message-ID: <d5d.2445f166.36221864@aol.com>

 
In a message dated 11/10/2008 05:12:11 GMT Daylight Time, smace at intt.net  
writes:

Has  anyone "upgraded" the oscillator on an older Datum BC637PCI card to
the MTI  crystal?  Is it as simple as changing the crystal and adjusting  the
osc gain?



---------
PS
 
Should have added to my previous waffle, I think the answer to this is  
yes:-)....
given the need to reset any changed values every time you power down and up  
again.
 
regards
 
Nigel
GM8PZR



**************   

From mark.amos at toast.net  Sat Oct 11 11:15:36 2008
From: mark.amos at toast.net (Mark Amos)
Date: Sat, 11 Oct 2008 11:15:36 -0400
Subject: [time-nuts] Time - an essential ingredient
Message-ID: <81a55d72fa87414f9454ff6000504211.mark.amos@toast.net>

Didier,

Well said! Your comment about "giving up in trying" reminds me of an epiphany I had recently.  

As a young, extremely intelligent and opinionated man, I once believed that the world was populated with 
stupid versions of me.  It took me many years to conclude that other people's opinions might actually have 
some value to me, and many more years to allow that their opinions didn't have to have value to me in order 
to be respected. 

In my case, I think it was mostly a matter of time spent in this fascinating world that drew me (or grew 
me) to the conclusion that diversity of opinion is one of the things that _makes_ this a fascinating world 
(albeit, often contentious.)

Regarding the OS religious wars: as an old boss once said (I think regarding CP/M vs MSDOS): "Operating 
System, Schmoperating System - can it run PASCAL?"

Mark
W8XR



From ghane0 at gmail.com  Sat Oct 11 11:31:03 2008
From: ghane0 at gmail.com (Sanjeev Gupta)
Date: Sat, 11 Oct 2008 23:31:03 +0800
Subject: [time-nuts] Sulzer Labs D-5 oscillator
In-Reply-To: <F17F40AD76BA4994849B95294A8FEA55@Robin>
References: <rk@timing-consultants.com>
	<995765D00C9A462CAED3D7B3FE1865C7@Robin>
	<20081011062021.61D43BCD5@ip-64-139-1-69.sjc.megapath.net>
	<F17F40AD76BA4994849B95294A8FEA55@Robin>
Message-ID: <158106a0810110831u41804d09p7a2d2e3853aabd0a@mail.gmail.com>

On Sat, Oct 11, 2008 at 3:06 PM, Rob Kimberley <rk at timing-consultants.com>wrote:

>
> It was only when I ventured into newsgroups that I came across bottom
> posting, which to me seemed totally illogical. I've read the pros of bottom
> posting (and the cons of top posting), but still can't get my head or my
> email prog (Outlook), around it.
>
>
I have recommended
   http://home.in.tum.de/~jain/software/outlook-quotefix/
and heard good things about it.  Fixes quotes, signature placement, etc.


-- 
Sanjeev Gupta
+65 98551208

From rdarlington at gmail.com  Sat Oct 11 11:40:39 2008
From: rdarlington at gmail.com (Robert Darlington)
Date: Sat, 11 Oct 2008 09:40:39 -0600
Subject: [time-nuts] Lassen IQ receiver
In-Reply-To: <E1KoY9X-0005J0-Sk@febo.com>
References: <001901c92b4a$217b9010$ad00a8c0@Morris1>
	<b3bd5fcb0810102158v4bb1f1e1u7c85ddf21ac51478@mail.gmail.com>
	<E1KoY9X-0005J0-Sk@febo.com>
Message-ID: <b3bd5fcb0810110840v35e81cc3g239ca77b5c402006@mail.gmail.com>

Hi Mike, I'll answer the questions in line with your email message, below...

On Sat, Oct 11, 2008 at 12:40 AM, Mike Monett <XDE-L2G3 at myamail.com> wrote:

>  "Robert Darlington" <rdarlington at gmail.com> wrote:
>
>  > I use  them  for  non-time keeping things.  You  need  to  use the
>  > configuration tool  to configure the ports so that they  both spit
>  > out NMEA,  and  the particular NMEA strings you want  to  see, and
>  > then save the configuration.
>
>  > Otherwise you  get  NMEA out of one port  and  the  Trimble binary
>  > format out  of the other. Do you have a copy of the  software? You
>  > can find it here:
>
>  >http://www.trimble.com/embeddedsystems/lasseniq.aspx?dtID=support
>
>  > Also, make  sure you have the IQ and not the SQ. The  SQ  only has
>  > one port but is otherwise pin compatible.
>
>   Robert,
>
>  These units look interesting. Do you mind if I ask some questions?
>
>  1. What kind of non-time keeping uses have you found for them?


The first project was an APRS beacon for a high altitude balloon project
which hasn't launched yet, but was tested in my car.  The last project was
for the local laboratory.  They developed a sampling system which had every
gadget but the kitchen sink in it, and every part was made out of
unobtanium.  In this case the gps board had been discontinued for about 4
years so I had to design a new one that would be the same physical size,
same hole spacing, and same pinout.  I figured if I was going to do this and
have a minimum run of 5 boards, I was going to make 2 for me (they needed 3
total).  In the picture you'll see the top half with the GPS module has a
white box around it.  This part I cut off after programming the GPS receiver
modules and installed in their gadget, the rest of the board gave me a
MAX232 (3.3 volt version if I remember right) and broke out both serial
ports to DB9 for easy hookup to a PC.  I should've added a PPS line but was
too concerned with keeping the board working when I cut it in half to really
think about more than what they needed.  What you can't see is the button
cell battery on the back for retaining constellation data

Here's the board: http://www.losalamostech.com/gps_board.jpg
Here's their gadget: http://www.*lanl*
.gov/orgs/tt/pdf/techs/hands_off_gun.pdf


>  2. How  well do they work indoors? Do you have to be near  a window?
>  What about inside a multi-story building?


We only tried it outside.  Their gadget got the short little ceramic patch
antenna.  I used the longer (5 meter I think) mag mount version in my car
when testing the APRS beacon.


>
>
>  3. How well do they handle constellation changes? Is there an abrupt
>  shift in position?
>

No clue!  Sorry.


>
>  4. Have you ever taken the shield off and looked inside? If  so, can
>  you see the crystal oscillator and tell whether it is a bare crystal
>  or a complete oscillator module?
>

No, but it comes off easy enough when not soldered down.  I'll try to pop
mine open and take some pictures of the guts for you later today.



>
>  5. How  much  do  they  cost? Do you know  of  any  others  that are
>  cheaper?
>

We paid somewhere on the order of $50 + the antenna.  Sparkfun sells them
here for $56:
http://www.sparkfun.com/commerce/product_info.php?products_id=163

They also sell the antennas and breakout boards that already have the tiny
little surface mount sockets (I have a few left if you end up buying one of
these).

The really interesting thing is that the manual states that the PPS output
is within 50ns of reality.   I plan on using one to discipline that Efratom
rubidium standard I was asking about earlier in the week.  By the way, the
connector from Mouser electronics came in and I'm ready to go, just waiting
on the part to come in from China.

-Bob



>
>  Thanks for your help!
>
>  Best Regards,
>
>  Mike Monett
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

From rdarlington at gmail.com  Sat Oct 11 11:51:49 2008
From: rdarlington at gmail.com (Robert Darlington)
Date: Sat, 11 Oct 2008 09:51:49 -0600
Subject: [time-nuts] Lassen IQ receiver
In-Reply-To: <001d01c92b97$b28beb20$ad00a8c0@Morris1>
References: <mailman.406.1223714630.2205.time-nuts@febo.com>
	<001d01c92b97$b28beb20$ad00a8c0@Morris1>
Message-ID: <b3bd5fcb0810110851n47ff136v82f0d6d2345643a0@mail.gmail.com>

Hi Morris,

The $ character should come before every NMEA sentence, and there should be
several of these in each data burst.  You probably can configure these
modules to only have one, and that might be what you're seeing.  Out of the
box the Lassen IQ spits out about 10 lines every second, each beginning with
the $ like this:

$GPGGA,184050.84,3907.3839,N,12102.4772,W,1,05,1.8,00543,M,,,,*33
$GPRMC,184050.84,A,3907.3839,N,12102.4772,W,00.0,000.0,080301,15,E*54
$GPGSA,A,3,24,07,09,26,05,,,,,,,,03.6,01.8,03.1*05
$PMGNST,02.12,3,T,534,05.0,+03327,00*40
$GPGLL,3907.3839,N,12102.4771,W,184051.812,A*2D
$GPGGA,184051.81,3907.3839,N,12102.4771,W,1,05,1.8,00543,M,,,,*34
$GPRMC,184051.81,A,3907.3839,N,12102.4771,W,00.0,000.0,080301,15,E*53
$GPGSA,A,3,24,07,09,26,05,,,,,,,,03.6,01.8,03.1*05
$GPGSV,3,1,08,07,57,045,43,09,48,303,48,04,44,144,,02,39,092,*7F
$GPGSV,3,2,08,24,18,178,44,26,17,230,41,05,13,292,43,08,01,147,*75
$GPGSV,3,3,08,,,,,,,,,,,,,,,,*71
$GPGLL,3907.3840,N,12102.4770,W,184052.812,A*21


This was spit out of a Magellan GPS and found randomly on the net here:
http://www.gpsinformation.org/dale/nmea.htm

Hook up your gps and watch it with Hyperterm or your terminal program of
choice.  It should fire up and start spitting this stuff out.  Can I ask
what you're doing with it?  Just curious.

-Bob


On Sat, Oct 11, 2008 at 5:51 AM, Morris Odell <vilgotch at bigpond.net.au>wrote:

> Thanks again Bob,
>
> Yes, that's what I thought it would do, but It doesn't seem to be so. My
> micro is programmed to identify the beginning of an NMEA string by the $
> character and there's only one per sec. Maybe the second string is
> concatenated onto the first one without the dollar symbol.
>
> Having said all that, in the time between my original post and this one I
> managed to get the TAIP output working and the micro to recognise it so I'm
> a happy man :-)
>
> Morris
>
> > Date: Sat, 11 Oct 2008 00:29:07 -0600
> > From: "Robert Darlington" <rdarlington at gmail.com>
> > Subject: Re: [time-nuts] Lassen IQ receiver
> >>
> > As far as alternating, you'll get the various NMEA strings in the order
> > you
> > choose (and the strings you choose) once a second.  You won't get one,
> > then
> > the other, then back to the first.  It'll be several  all at once, and
> > that
> > block will repeat once a second.  I suppose you could select just the two
> > you want, but they'd come in on the same data burst, repeating once a
> > second.
> >
> > first string
> > second string
> > <1 second pause>
> > first string
> > second string
> > <1 second pause>
> > etc.
> >
> > I don't know for sure if you can have port 1 setup with a particular set
> > of
> > NMEA data strings and port 2 setup with a different set.  Assuming you
> > can't
> > do that (meaning they have to be the same NMEA data), you can probably
> > have
> > both ports spit out everything you'd need and ignore what you don't need
> > in
> > software.
> >
> > -Bob
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

From didier at cox.net  Sat Oct 11 12:18:45 2008
From: didier at cox.net (Didier Juges)
Date: Sat, 11 Oct 2008 11:18:45 -0500
Subject: [time-nuts] Sulzer Labs D-5 oscillator
In-Reply-To: <158106a0810110831u41804d09p7a2d2e3853aabd0a@mail.gmail.com>
References: <rk@timing-consultants.com><995765D00C9A462CAED3D7B3FE1865C7@Robin><20081011062021.61D43BCD5@ip-64-139-1-69.sjc.megapath.net><F17F40AD76BA4994849B95294A8FEA55@Robin>
	<158106a0810110831u41804d09p7a2d2e3853aabd0a@mail.gmail.com>
Message-ID: <B5C2D54C422C4128866DF7A3D23ACC3B@didierhp>

time-nuts-bounces at febo.com wrote:
> On Sat, Oct 11, 2008 at 3:06 PM, Rob Kimberley
> <rk at timing-consultants.com>wrote:
> 
>> 
>> It was only when I ventured into newsgroups that I came across bottom
>> posting, which to me seemed totally illogical. I've read the pros of
>> bottom posting (and the cons of top posting), but still can't get my
>> head or my email prog (Outlook), around it.
>> 
>> 
> I have recommended
>    http://home.in.tum.de/~jain/software/outlook-quotefix/
> and heard good things about it.  Fixes quotes, signature
> placement, etc.

Sanjeev,

OK, I just installed it, let me try this....

It's amazing, it looks as if Outlook was smartified! Did not know it was
possible!

Did not even have to read any doc or go into any setup!!!

(well,maybe I should, it looks like it eats the last poster's signature...)

Well, I hope nobody is using Blackberrys on this list from now on!

Thanks,

Didier KO4BB



From smace at intt.net  Sat Oct 11 12:26:05 2008
From: smace at intt.net (Scott Mace)
Date: Sat, 11 Oct 2008 11:26:05 -0500
Subject: [time-nuts] BC637PCI
In-Reply-To: <d5d.2445f166.36221864@aol.com>
References: <d5d.2445f166.36221864@aol.com>
Message-ID: <48F0D39D.7030008@intt.net>

Nigel, thanks for the detailed response.  I noticed the password option in
the advanced menu as well.  I ran it overnight locked to a 1-PPS feed
and it seemed to stay witin +-200ns.  Not spectacular, but within
spec according to the older datasheets.  I am mainly interested in the card
as a timecode generator.  However it looks like it might be more convenient
to just feed the card an external 10mhz and not use the internal oscillator.
Also, the RTC battery is toast, so it looks like I'll be replacing that at
some point.

	Scott

GandalfG8 at aol.com wrote:
>  
> In a message dated 11/10/2008 05:12:11 GMT Daylight Time, smace at intt.net  
> writes:
> 
> Has  anyone "upgraded" the oscillator on an older Datum BC637PCI card to
> the MTI  crystal?  Is it as simple as changing the crystal and adjusting  the
> osc gain?
> 
> 
> 
> ---------
> PS
>  
> Should have added to my previous waffle, I think the answer to this is  
> yes:-)....
> given the need to reset any changed values every time you power down and up  
> again.
>  
> regards
>  
> Nigel
> GM8PZR
> 
> 
> 
> **************   
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 
> 


From XDE-L2G3 at myamail.com  Sat Oct 11 13:18:59 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Sat, 11 Oct 2008 13:18:59 -0400
Subject: [time-nuts] What is the best counter for a Time Nuts?
References: <d43.272633eb.361f1d99@aol.com>
Message-ID: <mailman.23.1223745568.2202.time-nuts@febo.com>

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From dforbes at dakotacom.net  Sat Oct 11 13:41:04 2008
From: dforbes at dakotacom.net (David Forbes)
Date: Sat, 11 Oct 2008 10:41:04 -0700
Subject: [time-nuts] Sound and time
In-Reply-To: <32205.1223727386@critter.freebsd.dk>
References: <32205.1223727386@critter.freebsd.dk>
Message-ID: <a06240500c51694dd5f61@[192.168.0.24]>

At 12:16 PM +0000 10/11/08, Poul-Henning Kamp wrote:
>
>As former sound technician...

I used to do that stuff too, being the bass player/sound guy in a 
cheesy bar band. Loads of fun!

Any more time nuts with sound reinforcement experience?

-- 

--David Forbes, Tucson, AZ
http://www.cathodecorner.com/


From rk at timing-consultants.com  Sat Oct 11 13:45:13 2008
From: rk at timing-consultants.com (Rob Kimberley)
Date: Sat, 11 Oct 2008 18:45:13 +0100
Subject: [time-nuts] Sulzer Labs D-5 oscillator
In-Reply-To: <B5C2D54C422C4128866DF7A3D23ACC3B@didierhp>
References: <rk@timing-consultants.com><995765D00C9A462CAED3D7B3FE1865C7@Robin><20081011062021.61D43BCD5@ip-64-139-1-69.sjc.megapath.net><F17F40AD76BA4994849B95294A8FEA55@Robin><158106a0810110831u41804d09p7a2d2e3853aabd0a@mail.gmail.com>
	<B5C2D54C422C4128866DF7A3D23ACC3B@didierhp>
Message-ID: <47557761FBE24B1D9970D22B6284A458@Robin>

Didier Juges wrote:
> time-nuts-bounces at febo.com wrote:
>> On Sat, Oct 11, 2008 at 3:06 PM, Rob Kimberley
>> <rk at timing-consultants.com>wrote:
>> 
>>> 
>>> It was only when I ventured into newsgroups that I came across
>>> bottom posting, which to me seemed totally illogical. I've read the
>>> pros of bottom posting (and the cons of top posting), but still
>>> can't get my head or my email prog (Outlook), around it.
>>> 
>>> 
>> I have recommended
>>    http://home.in.tum.de/~jain/software/outlook-quotefix/
>> and heard good things about it.  Fixes quotes, signature placement,
>> etc.
> 
> Sanjeev,
> 
> OK, I just installed it, let me try this....
> 
> It's amazing, it looks as if Outlook was smartified! Did not know it
> was possible! 
> 
> Did not even have to read any doc or go into any setup!!!
> 
> (well,maybe I should, it looks like it eats the last poster's
> signature...) 
> 
> Well, I hope nobody is using Blackberrys on this list from now on!
> 
> Thanks,
> 
> Didier KO4BB
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow
> the instructions there. 

Just installed Quotefix in my Outlook 2003, and thought I'd try it out.
Amazing!

:-)

Rob Kimberley



From rk at timing-consultants.com  Sat Oct 11 13:46:06 2008
From: rk at timing-consultants.com (Rob Kimberley)
Date: Sat, 11 Oct 2008 18:46:06 +0100
Subject: [time-nuts] Sulzer Labs D-5 oscillator
In-Reply-To: <158106a0810110831u41804d09p7a2d2e3853aabd0a@mail.gmail.com>
References: <rk@timing-consultants.com><995765D00C9A462CAED3D7B3FE1865C7@Robin><20081011062021.61D43BCD5@ip-64-139-1-69.sjc.megapath.net><F17F40AD76BA4994849B95294A8FEA55@Robin>
	<158106a0810110831u41804d09p7a2d2e3853aabd0a@mail.gmail.com>
Message-ID: <AF3CE91F70A945899B7C5A64AFF5FE38@Robin>

Sanjeev Gupta wrote:
> On Sat, Oct 11, 2008 at 3:06 PM, Rob Kimberley
> <rk at timing-consultants.com>wrote: 
> 
>> 
>> It was only when I ventured into newsgroups that I came across bottom
>> posting, which to me seemed totally illogical. I've read the pros of
>> bottom posting (and the cons of top posting), but still can't get my
>> head or my email prog (Outlook), around it.
>> 
>> 
> I have recommended
>    http://home.in.tum.de/~jain/software/outlook-quotefix/
> and heard good things about it.  Fixes quotes, signature placement,
> etc. 

Sanjeev,

Thank you for sending this - it works beatifully.

Rob Kimberley



From jherrero at hvsistemas.es  Sat Oct 11 13:52:05 2008
From: jherrero at hvsistemas.es (Javier Herrero)
Date: Sat, 11 Oct 2008 19:52:05 +0200
Subject: [time-nuts] Sound and time
In-Reply-To: <a06240500c51694dd5f61@[192.168.0.24]>
References: <32205.1223727386@critter.freebsd.dk>
	<a06240500c51694dd5f61@[192.168.0.24]>
Message-ID: <48F0E7C5.5030306@hvsistemas.es>

David Forbes escribi?:
> At 12:16 PM +0000 10/11/08, Poul-Henning Kamp wrote:
>> As former sound technician...
>
> I used to do that stuff too, being the bass player/sound guy in a 
> cheesy bar band. Loads of fun!
>
> Any more time nuts with sound reinforcement experience?
>
Not in the same way... I spent some time long ago working as service 
technician repairing professional sound equipment :)

Regards,

Javier

-- 
------------------------------------------------------------------------
Javier Herrero                            EMAIL: jherrero at hvsistemas.com
HV Sistemas S.L.                          PHONE:         +34 949 336 806
Los Charcones, 17A                        FAX:           +34 949 336 792
19170 El Casar - Guadalajara - Spain      WEB: http://www.hvsistemas.com



From tvb at LeapSecond.com  Sat Oct 11 14:38:16 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Sat, 11 Oct 2008 11:38:16 -0700
Subject: [time-nuts] Sulzer Labs D-5 oscillator
References: <8E8D23D235D70840B6582917DF27898006935BCD@temps153538.tms-ltd.com>
	<002f01c92ae2$e2d623f0$2801a8c0@pc52>
Message-ID: <001c01c92bd0$8d62e3b0$0700a8c0@pc52>

Paul,

Did you get what you needed?  If the schematic at:
http://www.leapsecond.com/museum/sul25-1/sul25bcl.gif
isn't clear enough, let me know. I have a full set of Sulzer
2.5 and 5 manuals here somewhere.

/tvb

>> I need a bit of help getting an old Sulzer D-5 5MHz oscillator to work. It
>> was built into a rack module with monitoring facilities and had been
>> slightly 'got-at' by the previous owner. Some of the connections were
>> pencilled on the case but not enough to give confidence about powering it
>> up. Has anybody got any information on this 'classic' design? Pin connection
>> data would be a great help, anything more would be wonderful!!
>> 
>> Thanks in advance,
>> 
>> Paul Reeves,    G8GJA
> 
> Does it look like either of these?
> 
> http://leapsecond.com/museum/sul25-1/
> http://leapsecond.com/museum/sul25-2/
> 
> /tvb




From magnus at rubidium.dyndns.org  Sat Oct 11 16:17:08 2008
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Sat, 11 Oct 2008 22:17:08 +0200
Subject: [time-nuts] What is the best counter for a Time Nuts?
In-Reply-To: <E1Koi7l-0005LG-VA@febo.com>
References: <d43.272633eb.361f1d99@aol.com> <E1Koi7l-0005LG-VA@febo.com>
Message-ID: <48F109C4.9020609@rubidium.dyndns.org>

Mike,

Mike Monett wrote:
>   The Allen deviation is used to describe the performance of  a stable
>   clock. Measuring the performance of a good clock requires  a counter
>   with resolution  down  to picosecond levels. As  Dr  Griffith points
>   out, some  modern counters may have internal signal  processing that
>   makes them unsuitable for this task.

Hold on!

What modern counters do is to use various means to improve on frequency 
and period measures. This makes the frequency and period measures 
unsuitable for futher processing as well as evaluation of expected 
performance when doing measures for Allan Deviation. However, what we do 
is usually not that measure, we to Time Interval measures for individual 
trigger points. When doing those measures these smoothing methods cannot 
be utilized. Then you are running on the bare-bone hardware performance 
with only the normal (traditional) translation skews.

I specifically cautioned Ulrich from making Allan Deviation performance 
estimate from the frequency performence for this reason. The smoothing 
will make such rule-of-thumb comparisions much harder.

>   Another thread  discussed using a mixer to  generate  the difference
>   frequency between  two oscillators, then measuring the  stability of
>   the resulting beat note:
> 
>   http://www.febo.com/pipermail/time-nuts/2005-July/019006.html
> 
>   The basic  principle  is sound. If the oscillators  were  running at
>   10MHz, and  the  frequency difference was 1 Hz, then  the  beat note
>   would be 1 Hz.
> 
>   This represents  one  part in 10 million, or  1e-7  of  the original
>   frequency. If  the  beat   note   is   measured  with  1 microsecond
>   resolution, the  overall resolution is 1e-7 / 1e-6 = 1e-13.  This is
>   beyond the capability of most commercial counters.
> 
>   The difficulty  with this approach is the output of a mixer is  at a
>   fairly low  level, perhaps 50 millivolts or so. The  frequency would
>   also be very low, perhaps 1 Hz. This means the counter would have to
>   trigger accurately on a very slow-rising, low amplitude signal.

This is not the actual problem. The actual problem is the slew rate of 
the signal. Even if the amplitude was several volts peak-to-peak the 
slew rate of the beat note is the main problem as the wideband noise of 
at the output added with the wideband noise of the counter input causes 
a random additive voltage modulation which can pre/post trigger around 
the ideal position with a RMS value of t_jitter = N_total / SR (this is 
a traditional trigger jitter formula).

The gain stages / slew rate amplifiers that Bruce and I have discussed 
contributes a significant gain which significantly goes beyond what a 
can come out of a mixer. Signal is clipped and filtered in order to 
improve signal to noise properties such that a minimal of noise is 
amplified while the slew rate is raised significantly.

>   This is  a very difficult measurement problem. The accuracy  will be
>   degraded by  noise,  such  as the 60Hz  AC  line  frequency  and its
>   harmonics, switching noise from the pc power supplies  and monitors,
>   radiation from nearby fluorescent lighting, plus thermal  noise from
>   the mixer and input stage of the amplifiers.

Not too hard really. The thing which makes it complex is that good 
signal to noise is needed both at the carrier frequency and beat 
frequency. Some knowledge of suitable measures should give adequate 
measures.

>   This low-level noise is very difficult to eliminate, especially when
>   coax cables are needed to transfer the desired signal from one place
>   to another.  The result is the measurement system is not as  good as
>   it could be.

Is it? Fighting ground loops to handle H fields is no big magic. Using 
mixers which ports is galvanically isolated helps. E fields is easier to 
handle at lower frequencies.

For the output port, the difference frequency needs the signal to noise 
properties. Traditional diffrential signal handling deals with both E 
and H field issues to such a level that other sources will dominate.

It should also be pointed out that carefull adjustment of both input 
port levels and the loading on the output port will have impact on 
performance as recorded in literature.

>   There is a solution to this problem. Another kind of mixer  called a
>   "digital mixer"  is ideally suited for this application.  It  uses a
>   d-flop, with one signal going to the clock pin, and one going to the
>   "D" input.  The resulting signal on the "Q' output is  the frequency
>   difference between the two signals.
> 
>   The output signal is a full logic level swing, perhaps 5 Volts, with
>   a risetime  of a couple of nanoseconds. This is an  ideal  signal to
>   pass on  a terminated coax cable to the counter.  The  schematic and
>   waveforms are shown in the attached GIF.

You will not solve the requirements for good dynamics. The digital input 
is highly non-linear and thus behaves like a mixer so due care is still 
needed, both at the beat frequency and carrier frequency. The benefit is 
the high slew rate.

It behaves like a sample and hold system, but with the quantization 
occuring before the sample action rather than after, which would could 
debated which is best, but the sampling action is certainly the mixing 
action causing problems, regardless of methods it is realized through.

Regardless of method, to achieve performance, you would need to maintain 
a certain degree of signal hygene to achieve the inteded or possible 
limit of the system.

>   The output  of  the  first d-flop is passed to  a  second  d-flop to
>   eliminate glitches due to metastability in the first stage. This can
>   occur when  the signal on the "D" input is exactly on  the switching
>   threshold when the clock transition occurs. The resulting glitch can
>   severely disrupt the following logic stages.
> 
>   In practice, it might be difficult to offset two  stable oscillators
>   by 1  Hz.  In this case, the frequencies can be  multiplied  to some
>   higher value. For example, the frequencies could be multiplied  by a
>   factor of 10 to 100MHz, and offset by 1 Hz.
> 
>   There may be some jitter in the leading edge of the beat  note since
>   the d-flop  may  or may not catch the transition as  it  crosses the
>   threshold on  the  "D" input. Instead of the  standard  +/-  1 clock
>   ambiguity in  digital circuits, the output could  be  several clocks
>   late. However,  if the counter had a resolution  of  100 nanoseconds
>   (10MHz clock),  the  extra  delay  is  much  less  than  the counter
>   resolution and should have no effect.

No, they add up unless you use the CLK signal for couting the beat 
frequency, in which case this is really the input trigger of a 
non-interpolating counter. If you use different clocks the beating 
pattern between them will introduce the additional noise signal.

>   The overall resolution in this example would be 1e-8 / 1e-7 = 1e-15.
> 
>   This is  achieved in one second, which is an impossible  task  for a
>   counter. This means the Allen deviation can be measured  much faster
>   than before, and with much higher accuracy.
> 
>   A simple LTspice analysis is included in the attached ZIP.

Where is the added noise? What D flip flops do you use? What is the ref 
inverter and what properties does it have?

It's an analogue world after all, so we need to evaluate it as an 
analogue system.

Cheers,
Magnus


From d.seiter at comcast.net  Sat Oct 11 17:12:35 2008
From: d.seiter at comcast.net (d.seiter at comcast.net)
Date: Sat, 11 Oct 2008 21:12:35 +0000
Subject: [time-nuts] Any ex-Cylink or PCom folks out there?
Message-ID: <101120082112.25039.48F116C3000DA18F000061CF22007507849D0A9B070A9CD20B@comcast.net>

Any ex-Cylink or Pcom folks out there?  

-Dave


From bruce.griffiths at xtra.co.nz  Sat Oct 11 17:53:50 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Sun, 12 Oct 2008 10:53:50 +1300
Subject: [time-nuts] What is the best counter for a Time Nuts?
In-Reply-To: <E1Koi7n-0005LG-VT@febo.com>
References: <d43.272633eb.361f1d99@aol.com> <E1Koi7n-0005LG-VT@febo.com>
Message-ID: <48F1206E.3070504@xtra.co.nz>

Mike Monett wrote:
>   The Allen deviation is used to describe the performance of  a stable
>   clock. Measuring the performance of a good clock requires  a counter
>   with resolution  down  to picosecond levels. As  Dr  Griffith points
>   out, some  modern counters may have internal signal  processing that
>   makes them unsuitable for this task.
>
>   Another thread  discussed using a mixer to  generate  the difference
>   frequency between  two oscillators, then measuring the  stability of
>   the resulting beat note:
>
>   http://www.febo.com/pipermail/time-nuts/2005-July/019006.html
>
>   The basic  principle  is sound. If the oscillators  were  running at
>   10MHz, and  the  frequency difference was 1 Hz, then  the  beat note
>   would be 1 Hz.
>
>   This represents  one  part in 10 million, or  1e-7  of  the original
>   frequency. If  the  beat   note   is   measured  with  1 microsecond
>   resolution, the  overall resolution is 1e-7 / 1e-6 = 1e-13.  This is
>   beyond the capability of most commercial counters.
>
>   The difficulty  with this approach is the output of a mixer is  at a
>   fairly low  level, perhaps 50 millivolts or so. The  frequency would
>   also be very low, perhaps 1 Hz. This means the counter would have to
>   trigger accurately on a very slow-rising, low amplitude signal.
>
>   
Not true, if both the RF and IF ports are saturated as usually 
recommended for phase detector operation, the output can be as high as 
2V pp (e.g. Minicircuits RPD-1).
The solution to the triggering problem with low slew rate input signals 
is simple, build a slope amplifier.
A slope amplifier (in optimised form) consists of a set of cascaded 
limiting amplifiers with gradually increasing gain and bandwidth.
Oliver Collins showed how to optimise the gain and bandwidth 
distribution to minimise the output noise.
I have since generalised his results to include the case where the input 
(self) noise for all amplifiers are not identical.
For further details/references see:
http://www.ko4bb.com/~bruce/ZeroCrossingDetectors.html 
<http://www.ko4bb.com/%7Ebruce/ZeroCrossingDetectors.html>

I have some spreadsheets for calculating the amplifier parameters both 
for the the restricted and general cases.
>   This is  a very difficult measurement problem. The accuracy  will be
>   degraded by  noise,  such  as the 60Hz  AC  line  frequency  and its
>   harmonics, switching noise from the pc power supplies  and monitors,
>   radiation from nearby fluorescent lighting, plus thermal  noise from
>   the mixer and input stage of the amplifiers.
>
>   This low-level noise is very difficult to eliminate, especially when
>   coax cables are needed to transfer the desired signal from one place
>   to another.  The result is the measurement system is not as  good as
>   it could be.
>   
Not if you use the built in mixer RF transformers to eliminate low 
frequency ground lops at the mixer input and use optical isolation for 
the output of the zero crossing detector comparator.
In other words a PCB using surface or through hole mount mixers is far 
better than using a packaged mixer with a common low frequency ground 
for all inputs and outputs.
It also pays to use a capacitive IF port termination for low beat 
frequencies (<100kHz) as this reduces the noise significantly.
>   There is a solution to this problem. Another kind of mixer  called a
>   "digital mixer"  is ideally suited for this application.  It  uses a
>   d-flop, with one signal going to the clock pin, and one going to the
>   "D" input.  The resulting signal on the "Q' output is  the frequency
>   difference between the two signals.
>   
And this isnt affected by low frequency ground loops?
>   The output signal is a full logic level swing, perhaps 5 Volts, with
>   a risetime  of a couple of nanoseconds. This is an  ideal  signal to
>   pass on  a terminated coax cable to the counter.  The  schematic and
>   waveforms are shown in the attached GIF.
>
>   The output  of  the  first d-flop is passed to  a  second  d-flop to
>   eliminate glitches due to metastability in the first stage. This can
>   occur when  the signal on the "D" input is exactly on  the switching
>   threshold when the clock transition occurs. The resulting glitch can
>   severely disrupt the following logic stages.
>
>   In practice, it might be difficult to offset two  stable oscillators
>   by 1  Hz.  In this case, the frequencies can be  multiplied  to some
>   higher value. For example, the frequencies could be multiplied  by a
>   factor of 10 to 100MHz, and offset by 1 Hz.
>
>   There may be some jitter in the leading edge of the beat  note since
>   the d-flop  may  or may not catch the transition as  it  crosses the
>   threshold on  the  "D" input. Instead of the  standard  +/-  1 clock
>   ambiguity in  digital circuits, the output could  be  several clocks
>   late. However,  if the counter had a resolution  of  100 nanoseconds
>   (10MHz clock),  the  extra  delay  is  much  less  than  the counter
>   resolution and should have no effect.
>
>   The overall resolution in this example would be 1e-8 / 1e-7 = 1e-15.
>
>   
What about the noise?
With a gate array is typically around 4E-11/tau.
The noise with dual flipflops may be a little lower but not stellar.
>   This is  achieved in one second, which is an impossible  task  for a
>   counter. This means the Allen deviation can be measured  much faster
>   than before, and with much higher accuracy.
>
>   A simple LTspice analysis is included in the attached ZIP.
>
>   Best Regards,
>
>   Mike Monett
>   
>
Mike

You've obviously never tried this, in practice its noise is a lot higher 
than you think, perhaps 2 orders of magnitude worse than a a double 
balanced mixer.
You need to breadboard this and do some tests.

Bruce



From holrum at hotmail.com  Sat Oct 11 17:57:06 2008
From: holrum at hotmail.com (Mark Sims)
Date: Sat, 11 Oct 2008 21:57:06 +0000
Subject: [time-nuts] Sound and time
In-Reply-To: <mailman.426.1223745568.2205.time-nuts@febo.com>
References: <mailman.426.1223745568.2205.time-nuts@febo.com>
Message-ID: <BLU125-W21F4EACCB858E1FB97538ACE340@phx.gbl>


Does a 7 megawatt seismic generator count?  Basically the world's largest sub woofer...

----------------------------------------
At 12:16 PM +0000 10/11/08, Poul-Henning Kamp wrote:
>
>As former sound technician...

I used to do that stuff too, being the bass player/sound guy in a 
cheesy bar band. Loads of fun!

Any more time nuts with sound reinforcement experience?

-- 

--David Forbes, Tucson, AZ
http://www.cathodecorner.com/


_________________________________________________________________
See how Windows connects the people, information, and fun that are part of your life.
http://clk.atdmt.com/MRT/go/msnnkwxp1020093175mrt/direct/01/

From sar10538 at gmail.com  Sat Oct 11 18:06:31 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Sun, 12 Oct 2008 11:06:31 +1300
Subject: [time-nuts] Sulzer Labs D-5 oscillator
In-Reply-To: <E1Kob3z-0007Bt-UW@febo.com>
References: <rk@timing-consultants.com>
	<995765D00C9A462CAED3D7B3FE1865C7@Robin>
	<20081011062021.61D43BCD5@ip-64-139-1-69.sjc.megapath.net>
	<F17F40AD76BA4994849B95294A8FEA55@Robin> <E1Koa4m-0006To-CA@febo.com>
	<1231b6a80810110218v699ec251ke1cff6779857ad65@mail.gmail.com>
	<E1Kob3z-0007Bt-UW@febo.com>
Message-ID: <1231b6a80810111506o7b416205laf934bbae8b646a6@mail.gmail.com>

Mike,

>  I'm in  the  process  of switching over  to  Ubuntu,  and  I already
>  checked - Wine handles Pimmy.

Whilst Wine is a very useful utility, I would only use it if there is
an absolute need to run a Windows application whith no equivalent. If
you are switching to Linux, you really would be advised look for
equivalent applications to the Windows ones. There are a real wealth
of them now an you are frequently spoilt by the varieties of the same
time of application. Although Wine will run a lot of Windows
applications, your experience will not be ideal, I can guarantee it.
There are bound to be 'issues' which will annoy you and I expect you
will only end up concluding that Linux is a load of rubbish as it is
not as good at running your Windows application as the real thing.

>  Does linux have an email client that handles multiple accounts?

Well, the obvious one is Thunderbird which will do all the things that
I can see that Pimmy can do, given my albeit brief overview of this
application from the parent website. Obviously, if you are going down
the Ubuntu path, there is Evolution which I think will fit the bill
for you and is the default email client for the Gnome desktop system.
Personally I use a KDE desktop which I consider is considerably more
powerful than Gnome and, coincidently, is a much closer style of a
desktop to the Windows experience. You can, of course, select KDE when
you install Ubuntu or go for a KDE orientated version called Kbuntu. I
know that everyone raves about Ubuntu but I've personally been with
SuSE for many years, and now with OpenSUSE, and I find it a very
polished distribution. It's just a case of what your preferences are.

>  BTW, my  reason for switching will probably affect more people  in a
>  couple of  years.  I am running Win98, and recently  bought  two new
>  Asus motherboards.  They no longer have drivers for Win98,  but they
>  do have drivers for Ubuntu and several other distros.

Well, Linux will run on most hardware these days as there are drivers
for many things, especially older hardware. The type of desktop can be
tailored to the performance capabilities of the hardware that it is
running on and you can almost run it on anything down to a wet lump of
string. I run OpenSUSE on a high end motherboard with quad core CPU,
high end graphics card and all the bells and whistles.

>  WinXP will  expire  soon,  and  VISTA is  a  disaster.  There  is no
>  guarantee the  next  release  will   be  any  better.  And  you will
>  eventually need  a new motherboard or two, so the handwriting  is on
>  the wall.

The good thing about Linux is that you can still run an up to date
version with good performance on quite mediocre hardware and new
versions don't generally drop support for older hardware. You
generally won't have to go out and buy a new printer, scanner,
graphics card, etc. when a new release comes out.

But, unless your a UNIX man, it's going to be a a steep learning curve
and it's all too easy to give up and throw it in the too hard bin.
Just persevere and think the Linux way. Eventually it will be like
those comfortable old slippers and you will enjoy the power and
flexibility you have in your hands.

73
Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From daun at yeagley.net  Sat Oct 11 18:12:19 2008
From: daun at yeagley.net (Daun Yeagley)
Date: Sat, 11 Oct 2008 18:12:19 -0400
Subject: [time-nuts] Sound and time
In-Reply-To: <BLU125-W21F4EACCB858E1FB97538ACE340@phx.gbl>
References: <mailman.426.1223745568.2205.time-nuts@febo.com>
	<BLU125-W21F4EACCB858E1FB97538ACE340@phx.gbl>
Message-ID: <6358C4D26D23493194E322D424A2D939@daundell>

Now *that* sounds like a lot of fun!

Many years ago I was in Beaverton, OR (yeah, TEK land), and there was this
disco called "Earthquake Ethel's". I guess they had a pretty fancy sound
system.... the feature every evening at around 9 pm (don't remember the real
time)... they had an "earthquake".  I leave the description to your
imagination!

Also, a lot of years ago (including high school and college), my thing was
to do lights and sound for theater.

Daun 

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Mark Sims
Sent: Saturday, October 11, 2008 5:57 PM
To: time-nuts at febo.com
Subject: [time-nuts] Sound and time


Does a 7 megawatt seismic generator count?  Basically the world's largest
sub woofer...

----------------------------------------
At 12:16 PM +0000 10/11/08, Poul-Henning Kamp wrote:
>
>As former sound technician...

I used to do that stuff too, being the bass player/sound guy in a cheesy bar
band. Loads of fun!

Any more time nuts with sound reinforcement experience?

-- 

--David Forbes, Tucson, AZ
http://www.cathodecorner.com/


_________________________________________________________________
See how Windows connects the people, information, and fun that are part of
your life.
http://clk.atdmt.com/MRT/go/msnnkwxp1020093175mrt/direct/01/
_______________________________________________
time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.





From brooke at pacific.net  Sat Oct 11 18:24:37 2008
From: brooke at pacific.net (Brooke Clarke)
Date: Sat, 11 Oct 2008 15:24:37 -0700
Subject: [time-nuts] Sound and time
In-Reply-To: <6358C4D26D23493194E322D424A2D939@daundell>
References: <mailman.426.1223745568.2205.time-nuts@febo.com>	<BLU125-W21F4EACCB858E1FB97538ACE340@phx.gbl>
	<6358C4D26D23493194E322D424A2D939@daundell>
Message-ID: <48F127A5.70805@pacific.net>

Hi:

In the late 1950's early 1960's FM stereo did not yet exist.  The method used 
was to use a receiver that could tune AM or FM but allowed receiving both at 
the same time.  So a station in S.F., maybe K101 got frequency assignments so 
that with one dial pointer position you were tuned to one of their stations on 
FM and the other on AM.  Later they used the new FM stereo broadcast system

One of their "sounds" was an earthquake and I think it was the one with the 
warning to not turn up the volume too high, because you may blow your speakers.
That may have been the source for "Earthquake Ethel's"?  James Gabbard 
(spelling? was the host)

Have Fun,

Brooke Clarke, N6GCE
http://www.prc68.com/P/Prod.html  Products I make and sell
http://www.prc68.com/Alpha.shtml  All my web pages listed based on html name
http://www.PRC68.com
http://www.precisionclock.com
http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Web Cam

Daun Yeagley wrote:
> Now *that* sounds like a lot of fun!
> 
> Many years ago I was in Beaverton, OR (yeah, TEK land), and there was this
> disco called "Earthquake Ethel's". I guess they had a pretty fancy sound
> system.... the feature every evening at around 9 pm (don't remember the real
> time)... they had an "earthquake".  I leave the description to your
> imagination!
> 
> Also, a lot of years ago (including high school and college), my thing was
> to do lights and sound for theater.
> 
> Daun 
> 
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
> Behalf Of Mark Sims
> Sent: Saturday, October 11, 2008 5:57 PM
> To: time-nuts at febo.com
> Subject: [time-nuts] Sound and time
> 
> 
> Does a 7 megawatt seismic generator count?  Basically the world's largest
> sub woofer...
> 
> ----------------------------------------
> At 12:16 PM +0000 10/11/08, Poul-Henning Kamp wrote:
>> As former sound technician...
> 
> I used to do that stuff too, being the bass player/sound guy in a cheesy bar
> band. Loads of fun!
> 
> Any more time nuts with sound reinforcement experience?
> 


From aa8k at comcast.net  Sat Oct 11 19:08:44 2008
From: aa8k at comcast.net (Mike Naruta AA8K)
Date: Sat, 11 Oct 2008 19:08:44 -0400
Subject: [time-nuts] Sound and time
In-Reply-To: <a06240500c51694dd5f61@[192.168.0.24]>
References: <32205.1223727386@critter.freebsd.dk>
	<a06240500c51694dd5f61@[192.168.0.24]>
Message-ID: <48F131FC.9010301@comcast.net>

I used to be the roadie for The Fourth Dynasty,
a hard rock band back in the 1960's.  Built a
neat box that the drummer could use to flash
various colored floods with his foot.  Built an
ultraviolet strobe light (this is in the 60's).
I even played an audio oscillator on certain
tunes.  We had so many high-powered amps that
it's a miracle that I can still hear.  At the
Music Dome (an old geodesic) we shook the dust
out of the building.  The bass player and I
used to grab a Hammond B3 organ and put it up
on the stage.  The B3 wasn't a home organ,
but a truly huge, heavy beast.  Coupled with
the Leslie speaker, it was an awesome sound.
I wonder where our Fender Telecasters are today.
The bass player used to build custom 15 inch
speakers; he was super at leatherette.  It
was neat watching the blue glow on the 6L6s.

The only time we lost a "battle of the bands"
was at one school where they gave it to the
hometown band.  The crowd wasn't happy and
the contact guy was apologetic, but we wound
up playing for free that night.  There were
some nice places, and some real sleazy ones;
a couple that almost needed the chicken wire.
We made a couple of 45s, but never got famous.
It was interesting learning about human
personalities by observing the band members
and the crowd.


Mike - AA8K


David Forbes wrote:
> At 12:16 PM +0000 10/11/08, Poul-Henning Kamp wrote:
>> As former sound technician...
> 
> I used to do that stuff too, being the bass player/sound guy in a 
> cheesy bar band. Loads of fun!
> 
> Any more time nuts with sound reinforcement experience?
> 


From magnus at rubidium.dyndns.org  Sat Oct 11 19:53:11 2008
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Sun, 12 Oct 2008 01:53:11 +0200
Subject: [time-nuts] Sound and time
In-Reply-To: <a06240500c51694dd5f61@[192.168.0.24]>
References: <32205.1223727386@critter.freebsd.dk>
	<a06240500c51694dd5f61@[192.168.0.24]>
Message-ID: <48F13C67.7000306@rubidium.dyndns.org>

David Forbes wrote:
> At 12:16 PM +0000 10/11/08, Poul-Henning Kamp wrote:
>> As former sound technician...
> 
> I used to do that stuff too, being the bass player/sound guy in a 
> cheesy bar band. Loads of fun!
> 
> Any more time nuts with sound reinforcement experience?
> 

Sure thing. One of my first jobs was to work on PA systems. I did the 
home work by trimming up active cross overs and associated limiters, 
measuring them and also hunt down hum and noise to get the dynamics way 
up. Catastroph limiters ensured we didn't burn the speakers and we could 
do 139 db SPL at 1 m in the mid range and 136 dB SPL at the top. We 
never used less than 4 a side. The amps could burn the elements without 
clipping, and the catastroph limiters ensured we never did that. What 
really kills your ears is amps clipping. Lots of nice overtones crashing 
out of the speaker. As for dynamics, if you where in a silent room you 
had to crash your head to the speaker to hear a very very faint noise 
while the system was at full power capable of burning your ears out if 
there was a signal. I did pseudo-anecoic impulse responce measurements 
for the sum of speaker responses as a standard thing.

I was also involved in line speakers as they appeared on the market. 
This was very early out. They changed the PA market for the better.

I still have a complete hearing. I can't even recall having tinitus 
after a concert or work. Ever.

Cheers,
Magnus


From True-Cal at swbell.net  Sat Oct 11 20:04:58 2008
From: True-Cal at swbell.net (Don Johnson)
Date: Sat, 11 Oct 2008 19:04:58 -0500
Subject: [time-nuts] COMPLETELY off topic - but I know you'll read
	itanyway.
References: <f616e0f80810110510p4e8e1a1fw932acf8093cc38ea@mail.gmail.com><48F09E4F.2030907@hvsistemas.es>
	<f616e0f80810110548j1af03d49r8405421b8d8e0f24@mail.gmail.com>
Message-ID: <954A2FF2247246C1B96372E05A3B601E@dv6000z>

Jim,

 

Ahh audio, my first love and almost 50-years of experience. You already have replies with the right answers but here is my 2-cents..

 

>I've dug out the manual and even though the specifications say it can do 4
>ohms in bridged mode, there is another statement that says it doesn't
>recommend it.

 

The recommendation is due to current limiting in the amplifier. The amplifier output impedance is doubled from the typical 4-ohm per channel to 8-ohm when bridged. If you loaded the bridged output with 4-ohm (both 8-ohm speakers in parallel), it would require double the current through each output stage in addition to 2x the draw from the power supply. Current limiting, probably in the power supply, would result at a much lower peak voltage from each channel. The result is less power (earlier clipping/distortion) with this lower than design point load. 

 

>"The A channel handles the positive voltage and the B channel becomes the
>negative, thus doubling the output voltage swing."

 

This is a very odd way to state what's happening in the bridged mode. You gatta love manuals written by the marketing department. Not totally wrong but only accurate during complex instances in time when the positive half of the output is indeed handled by ch-A and the negative by ch-B. In another instance however, this will be reversed. A more accurate description is what someone else has already stated as a push-pull arrangement of the out-of-phase driven channels. The bridge mode switch couples one of the input channels to both output stages but also inserts an additional op-amp stage (phase inverter) in only one of the channels. Now as the input signal goes positive, the "hot" terminal of ch-A will be driven positive while the "hot" terminal of ch-B will be driven negative equally. All this reverses as the input signal goes negative.

 

The clincher for you to NOT operate in bridge mode is that you have TWO speakers of the correct impedance to match each channel separately. Just drive both input channels with a Y adapter from your mono source and you will have the best arrangement. If there is ever a time that you want to only drive one of the 8-ohm speakers, now you would want to bridge the amp and connect the one speaker accordingly.

 

Regards...

Don




  ----- Original Message ----- 
  From: Jim Palfreyman 
  To: Discussion of precise time and frequency measurement 
  Sent: Saturday, October 11, 2008 7:48 AM
  Subject: Re: [time-nuts] COMPLETELY off topic - but I know you'll read itanyway.


  Thanks folks for your quick replies.

  I've dug out the manual and even though the specifications say it can do 4
  ohms in bridged mode, there is another statement that says it doesn't
  recommend it.

  Here is what it says about bridged mode:

  "The A channel handles the positive voltage and the B channel becomes the
  negative, thus doubling the output voltage swing."

  Needless to say, Poul's comment regarding running them as two separate
  channels because if one fails I'll have another as a spare is the clincher
  for me. Being from an IT background - backup is all important.

  Thanks folks!



  2008/10/11 Javier Herrero <jherrero at hvsistemas.es>

  > If 500W are specified for a 4 ohm load, you will only obtain 250W for
  > each channel over a 8 ohm speaker. In bridged mode, it is not true that
  > basically one channel drives the upper part of the sine and the other
  > the lower: they operate in push-pull, supplying each side of the speaker
  > with opposite phases so you will obtain the double peak-to-peak  voltage
  > value over the load than in the single ended configuration. Double
  > voltage would mean four-times power, so the amplifier surely is not
  > rated for the same load in bridged mode than in single-ended two-channel
  > mode. If minimum load for each channel is 4 ohm in single-ended mode,
  > usually it is 8 ohm for two channels in bridged mode.
  >
  > So if you have 8 ohm speakers... use it in single ended mode (better
  > reliability also, as Poul-Henning pointed), and you will get 250W per
  > channel. In brigde mode, you could only put the two speakers in parallel
  > if the amplifier is rated for 4 ohm loads in bridged mode.
  >
  > Regards,
  >
  > Javier
  >
  > Jim Palfreyman escribi?:
  > > OK I have an interesting but simple problem that has nothing to do with
  > > time. But I'm sure someone on this list will know. And besides I can't be
  > > stuffed finding another list with such a good S/N ratio.
  > >
  > > In my spare time I play in a band.
  > >
  > > I have a 1000W amplifier that can be either two 500W stereo channels or a
  > > single 1000W mono running in "bridged" mode. (Basically one channel
  > > amplifies the upper part of the sine curve and the other the lower.)
  > >
  > > The amp can drive speakers down to 4 ohms.
  > >
  > > I have two 8 ohm speakers.
  > >
  > > The source is mono.
  > >
  > > Do I run each 8 ohm speaker on its own 500W channel?
  > >
  > > or
  > >
  > > Do I run in bridged mode and put the two speakers in parallel onto the
  > 1000W
  > > amplifier?
  > >
  > > Any takers?
  > >
  > > Regards,
  > >
  > > Jim
  > > _______________________________________________
  > > time-nuts mailing list -- time-nuts at febo.com
  > > To unsubscribe, go to
  > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
  > > and follow the instructions there.
  > >
  > >
  >
  > --
  > ------------------------------------------------------------------------
  > Javier Herrero                            EMAIL: jherrero at hvsistemas.com
  > HV Sistemas S.L.                          PHONE:         +34 949 336 806
  > Los Charcones, 17A                        FAX:           +34 949 336 792
  > 19170 El Casar - Guadalajara - Spain      WEB: http://www.hvsistemas.com
  >
  >
  > _______________________________________________
  > time-nuts mailing list -- time-nuts at febo.com
  > To unsubscribe, go to
  > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
  > and follow the instructions there.
  >
  _______________________________________________
  time-nuts mailing list -- time-nuts at febo.com
  To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
  and follow the instructions there.

From XDE-L2G3 at myamail.com  Sat Oct 11 20:07:16 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Sat, 11 Oct 2008 20:07:16 -0400
Subject: [time-nuts] What is the best counter for a Time Nuts?
References: <d43.272633eb.361f1d99@aol.com>
Message-ID: <mailman.24.1223770064.2202.time-nuts@febo.com>

  Two corrections: 

  The denominators in the following equations have the  wrong polarity
  in the exponent:

  > the overall resolution is 1e-7 / 1e-6 = 1e-13.

  This should read:

  > the overall resolution is 1e-7 / 1e+6 = 1e-13.

  Similarly

  > The overall  resolution  in this example would be  1e-8  /  1e-7 =
  > 1e-15.

  This should read:

  > The overall  resolution  in this example would be  1e-8  /  1e+7 =
  > 1e-15.

  These were obvious typos that I hope did not confuse anyone.

  Best Regards

  Mike Monett


From sar10538 at gmail.com  Sat Oct 11 20:11:42 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Sun, 12 Oct 2008 13:11:42 +1300
Subject: [time-nuts] COMPLETELY off topic - but I know you'll read
	itanyway.
In-Reply-To: <954A2FF2247246C1B96372E05A3B601E@dv6000z>
References: <f616e0f80810110510p4e8e1a1fw932acf8093cc38ea@mail.gmail.com>
	<48F09E4F.2030907@hvsistemas.es>
	<f616e0f80810110548j1af03d49r8405421b8d8e0f24@mail.gmail.com>
	<954A2FF2247246C1B96372E05A3B601E@dv6000z>
Message-ID: <1231b6a80810111711y3c96625bt391e379abc8ed2c5@mail.gmail.com>

2008/10/12 Don Johnson <True-Cal at swbell.net>:
>>"The A channel handles the positive voltage and the B channel becomes the
>>negative, thus doubling the output voltage swing."
>
> This is a very odd way to state what's happening in the bridged mode. You gatta love manuals written by the marketing department. Not totally wrong but only accurate during complex instances in time when the positive half of the output is indeed handled by ch-A and the negative by ch-B. In another instance however, this will be reversed. A more accurate description is what someone else has already stated as a push-pull arrangement of the out-of-phase driven channels. The bridge mode switch couples one of the input channels to both output stages but also inserts an additional op-amp stage (phase inverter) in only one of the channels. Now as the input signal goes positive, the "hot" terminal of ch-A will be driven positive while the "hot" terminal of ch-B will be driven negative equally. All this reverses as the input signal goes negative.

It should be called differential output.

73
Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From sar10538 at gmail.com  Sat Oct 11 20:13:37 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Sun, 12 Oct 2008 13:13:37 +1300
Subject: [time-nuts] What is the best counter for a Time Nuts?
In-Reply-To: <E1KooUr-0002Fl-Dm@febo.com>
References: <d43.272633eb.361f1d99@aol.com> <E1KooUr-0002Fl-Dm@febo.com>
Message-ID: <1231b6a80810111713x34436451qd398db01703aa269@mail.gmail.com>

2008/10/12 Mike Monett <XDE-L2G3 at myamail.com>:
>  Two corrections:
>
>  The denominators in the following equations have the  wrong polarity
>  in the exponent:
>
>  > the overall resolution is 1e-7 / 1e-6 = 1e-13.
>
>  This should read:
>
>  > the overall resolution is 1e-7 / 1e+6 = 1e-13.
>
>  Similarly
>
>  > The overall  resolution  in this example would be  1e-8  /  1e-7 =
>  > 1e-15.
>
>  This should read:
>
>  > The overall  resolution  in this example would be  1e-8  /  1e+7 =
>  > 1e-15.
>
>  These were obvious typos that I hope did not confuse anyone.
>
>  Best Regards
>
>  Mike Monett
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

I was confused even before I read the posts :)

73
Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From XDE-L2G3 at myamail.com  Sat Oct 11 20:32:51 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Sat, 11 Oct 2008 20:32:51 -0400
Subject: [time-nuts] Sulzer Labs D-5 oscillator
References: <rk@timing-consultants.com>
	<995765D00C9A462CAED3D7B3FE1865C7@Robin>
	<20081011062021.61D43BCD5@ip-64-139-1-69.sjc.megapath.net>
	<F17F40AD76BA4994849B95294A8FEA55@Robin>
	<E1Koa4m-0006To-CA@febo.com>
	<1231b6a80810110218v699ec251ke1cff6779857ad65@mail.gmail.com>
	<E1Kob3z-0007Bt-UW@febo.com>
	<1231b6a80810111506o7b416205laf934bbae8b646a6@mail.gmail.com>
Message-ID: <mailman.25.1223771613.2202.time-nuts@febo.com>


  "Steve Rooke" <sar10538 at gmail.com> wrote:

  >  Mike,

  >> I'm in  the  process of switching over to Ubuntu,  and  I already
  >> checked - Wine handles Pimmy.

  > Whilst Wine is a very useful utility, I would only use it if there
  > is an  absolute  need  to   run  a  Windows  application  whith no
  > equivalent. If  you  are switching to Linux, you  really  would be
  > advised look for equivalent applications to the Windows ones.

  I have been running Eagle pcb cad on Suse since 2001. I am extremely
  happy with  linux. But LTspice requires Wine, Pimmy will run  on it,
  and also  Hotkeyz.  This  will   tide   me  over  until  I  can find
  replacements, but LTspice will always need Wine.

  My friend  down  the hall keeps experimenting  with  different Linux
  distros and  tells me about his experiences, some good and  some not
  so good. For now, it looks like I will be running Suse and Ubuntu.

  >> Does linux have an email client that handles multiple accounts?

  > Well, the obvious one is Thunderbird which will do all  the things
  > that I  can see that Pimmy can do, given my albeit  brief overview
  > of this application from the parent website.

  I tried  Thunderbird some time ago, but I think I gave  up  since it
  would not  handle multiple accounts like Pimmy does.  That  may have
  changed.

  But the  message  there  is  to go to KasMail  and  get  a  bunch of
  disposable email addresses. Then kill any that pick up spam. But you
  need a  client  that  takes  care of  all  the  details  in handling
  multiple accounts,  or  you very quickly get in  a  lot  of trouble.
  Pimmy does that very well.

  I just  checked  - the last spam I got was a  phishing  email  for a
  London bank. It was last August 14, which is two months ago.

  One spam every two months is not so bad. I can handle that:)

  > Obviously, if  you  are  going  down  the  Ubuntu  path,  there is
  > Evolution which  I  think  will fit the bill for  you  and  is the
  > default email  client for the Gnome desktop  system.  Personally I
  > use a  KDE desktop which I consider is considerably  more powerful
  > than Gnome and, coincidently, is a much closer style of  a desktop
  > to the Windows experience. You can, of course, select KDE when you
  > install Ubuntu or go for a KDE orientated version called Kbuntu. I
  > know that  everyone  raves about Ubuntu but  I've  personally been
  > with SuSE  for many years, and now with OpenSUSE, and I find  it a
  > very polished  distribution.  It's   just   a  case  of  what your
  > preferences are.

  My preferences are stuff that works, doesn't crash and doesn't erase
  my files.  Once  you are inside a CAD program  or  writing  code, it
  really doesn't matter what system you are on as long as it works.

  [...]

  > The good thing about Linux is that you can still run an up to date
  > version with  good performance on quite mediocre hardware  and new
  > versions don't  generally  drop support  for  older  hardware. You
  > generally won't  have  to go out and buy a  new  printer, scanner,
  > graphics card, etc. when a new release comes out.

  > But, unless  your a UNIX man, it's going to be a a  steep learning
  > curve and  it's  all too easy to give up and throw it  in  the too
  > hard bin.  Just persevere and think the Linux  way.  Eventually it
  > will be like those comfortable old slippers and you will enjoy the
  > power and flexibility you have in your hands.

  I really  have no problems running Linux. I still write  most  of my
  programs in  DOS, so commandline switches are not an  issue.  I just
  include them  in  my programs so I don't have  to  remember  all the
  silly options, like all the stuff you can do with PKZip.

  So far,  I  just  haven't  had  the time  to  sit  down  and  do the
  conversion to  Linux.  But  now my lab is expanding,  and  I  can no
  longer get motherboards with drivers for Win98, so I have no choice.

  And that was my message for those still hoping XP will last forever.

  It won't. Bill will see to that:)

  >73
  >Steve

  >Steve Rooke - ZL3TUV & G8KVD
  >Omnium finis imminet

  Thanks for the encouragement!

  Best Regards,

  Mike Monett


From XDE-L2G3 at myamail.com  Sat Oct 11 21:19:05 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Sat, 11 Oct 2008 21:19:05 -0400
Subject: [time-nuts] What is the best counter for a Time Nuts?
References: <d43.272633eb.361f1d99@aol.com> <E1Koi7l-0005LG-VA@febo.com>
	<48F109C4.9020609@rubidium.dyndns.org>
Message-ID: <mailman.26.1223774367.2202.time-nuts@febo.com>

  Magnus Danielson <magnus at rubidium.dyndns.org> wrote:

  [...]

  > It's an analogue world after all, so we need to evaluate it  as an
  > analogue system.

  >Cheers,
  >Magnus

  Magnus,

  Thank you for your reply. I challenge you to a duel.  Picoseconds at
  50 paces:)

  You build  your  system  and  show the  results.  I  should  have my
  complete system running by Christmas, and will post everything.

  Perhaps we can agree on a common set of oscillators. I will  have an
  old LPRO  Rubidium  and two IsoTemp 134 OXCO's from  eBay,  plus GPS
  time.

  Bet I beat you:)

  Best Regards,

  Mike Monett


From mikes at flatsurface.com  Sat Oct 11 22:26:16 2008
From: mikes at flatsurface.com (Mike S)
Date: Sat, 11 Oct 2008 22:26:16 -0400
Subject: [time-nuts] What is the best counter for a Time Nuts?
In-Reply-To: <48F109C4.9020609@rubidium.dyndns.org>
References: <d43.272633eb.361f1d99@aol.com> <E1Koi7l-0005LG-VA@febo.com>
	<48F109C4.9020609@rubidium.dyndns.org>
Message-ID: <20081012022623.45F3A1165C3@hamburg.alientech.net>

At 04:17 PM 10/11/2008, Magnus Danielson wrote...
>It's an analogue world after all, so we need to evaluate it as an
>analogue system.

I take it you don't agree with quantum theory (mechanics, 
electrodynamics, chromodynamics, etc.)?

I suppose we're still far from measuring at the scale of Planck time, 
so it's hard to prove one way or the other. Still, quantum physics has 
been empirically useful where analog physics fails. 



From XDE-L2G3 at myamail.com  Sat Oct 11 22:52:26 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Sat, 11 Oct 2008 22:52:26 -0400
Subject: [time-nuts] What is the best counter for a Time Nuts?
References: <d43.272633eb.361f1d99@aol.com> <E1Koi7n-0005LG-VT@febo.com>
	<48F1206E.3070504@xtra.co.nz>
Message-ID: <mailman.27.1223779975.2202.time-nuts@febo.com>

  > Mike

  > You've obviously never tried this, in practice its noise is  a lot
  > higher than you think, perhaps 2 orders of magnitude worse  than a
  > double balanced mixer.

  > You need to breadboard this and do some tests.

  > Bruce

  Bruce,

  Thank you for the reply. Please let me introduce myself.

  I know this circuit very well. I've been using it since  1970, where
  it formed  the  basis  of development work  that  led  to  my second
  patent, US 4533881. Among other things, this patent was the first to
  recognize the  problem  of   deadband   in  the  PLL phase/frequency
  detector, and  shows how to fix it. People still get  it  wrong even
  today.

  That patent led to an amazing discovery, documented in the paper:

  "Effect of  Bitshift   Distribution   on   Error   Rate  in Magnetic
  Recording", Eric R. Katz and Thomas G. Campbell, IEEE Transaction on
  Magnetics, Vol. MAG-15, No. 3, May 1979, pp 1050-1053.

  This technique  saved  the  hard  disk  drive  industry  hundreds of
  millions, if not billions of dollars. It did this by  separating the
  contributions of  the head, media, preamplifier, servo  system, disk
  defects, external  EMI,  and anything else that  affected  the error
  rate. It gave manufacturing a very quick test to tell if a drive was
  meeting the error rate spec, and tells what to do if it failed.

  It also  gave  head  and media manufacturers a  way  to  measure the
  performance of  their  products, and a way to  meet  the competition
  that was  using the same technique. It told R&D  engineers  how well
  their design  was  working, and what to do to improve it.  It  had a
  tremendous effect  on  every disk drive company on  the  planet, and
  there were over 220 at the peak.

  I made a great deal of money developing test systems that  used this
  technique for  manufacturers all over the world. I owned a  house in
  Saratoga Hills in Silicon Valley. I had two Mercedes and three Lexus
  for my  managers,  and gave a bunch of Toyota station  wagons  to my
  staff so they wouldn't have problems getting to work. I  helped most
  of my staff buy houses. I bought this plane brand new,  Piper Malibu
  N4360V.

  http://www.jetphotos.net/viewphoto.php?id=5874208&nseq=0

  This is  a twin turbocharged with constant speed  prop, pressurized,
  retractable, six-place  high  performance  aircraft  with  a service
  ceiling of  25,000 ft. That is above most of the weather, and  I put
  over 750  hours  on it flying to customers all over the  US.  It was
  truly the nicest plane I have ever had the pleasure to fly,  but you
  have to  watch  it on takeoff when the turbos spool  up.  The torque
  will take you into the weeds if you are not ready for it. It is very
  nice to see it is still in the air:)

  All of this resulted from work using the circuit I  described above,
  so I  know it pretty well. It works a lot better than  you  think it
  does.

  It also  forms the basis of two of my latest inventions,  which will
  be disclosed  as soon as I have time to get my new web  site  up and
  running.

  The old  site was finally taken down by Microsoft, so  I  can't give
  you a  working  url. But at this moment,  searching  for  the phrase
  "binary sampler"  in quotes gives me the first four hits  in google,
  so you  can see it was up until recently. Unfortunately  the WayBack
  machine doesn't link to images, so I can't send you there to see how
  it works.  But  I  should  have  the  above  circuit  running around
  Christmas, along with some other new stuff.

  I'll be happy to discuss these issues when there is hardware to make
  measurements on.

  Best Regards,

  Mike Monett


From mccorkle at ptialaska.net  Sat Oct 11 22:54:22 2008
From: mccorkle at ptialaska.net (Richard H McCorkle)
Date: Sat, 11 Oct 2008 18:54:22 -0800 (AKDT)
Subject: [time-nuts] Sound and time
In-Reply-To: <a06240500c51694dd5f61@[192.168.0.24]>
References: <32205.1223727386@critter.freebsd.dk>
	<a06240500c51694dd5f61@[192.168.0.24]>
Message-ID: <11236.206.174.39.163.1223780062.squirrel@mymail.acsalaska.net>

> At 12:16 PM +0000 10/11/08, Poul-Henning Kamp wrote:
>>
>>As former sound technician...
>
> I used to do that stuff too, being the bass player/sound guy in a
> cheesy bar band. Loads of fun!
>
> Any more time nuts with sound reinforcement experience?
>
> --
>
> --David Forbes, Tucson, AZ
> http://www.cathodecorner.com/

Hi Dave,

In the 70's and 80's my partner and I in Fairbanks worked with
another friend in Anchorage and together we did sound for hundreds
of commercial concerts in Alaska. Shipping equipment up here was
a major issue for promoters and with 20KW sound systems in both major
cities we got a lot of work. Eventually dedicated facilities with
built-in sound systems were constructed which put us out of business.
Sure was fun while it lasted though!

Richard





From Charlie.Myers at ps.net  Sun Oct 12 00:09:23 2008
From: Charlie.Myers at ps.net (Myers, Charlie)
Date: Sat, 11 Oct 2008 23:09:23 -0500
Subject: [time-nuts]  What is the best counter for a Time Nuts?
Message-ID: <8C1E01B3C43FF44EAC6658014AB0617A02A93905@PSCDALPEXCH03.perotsystems.net>

Hello to the Time Nuts,

I have been reading the mail on this topic for the last week or so with
great interest.  Lots of interesting ideas have been put forth for
measuring frequency to a high degree of precision and for comparing a 10
MHz clock's frequency to a highly accurate 10Mhz frequency "standard".

The way I measure the frequency of a 10 MHz clock is to compare it to a
second 10MHz clock of known accuracy and stability, not only with a
frequency counter but also with a phase meter.  

I have several GPS disciplined OCXO's, one GPS disciplined Rubidium
oscillator, and several free running rubidium oscillators.  I measure
the frequency of an unknown 10 MHz clock using a 2 step process.  First
I measure the unknown 10 MHz clock using an HP 5384A reciprocal counter
that employs my known 10 MHz clock as its external timebase.  I set the
gate time to 10 seconds and the counter delivers a frequency measurement
with a resolution of less than 3 mhz (3 millihertz).  So, assuming my
known timebase is "bang on", I know the frequency of the unknown 10 MHz
source to an accuracy of roughly 3e-10 or 3 parts in 10 billion.  

To get a more precise measurement of the frequency difference between
the two 10 MHz clocks, I supply the known 10 MHz clock to the Channel A
input of an HP 3575A Gain-Phase meter and the unknown 10 MHz clock to
the channel B input of the Gain-Phase meter.  I measure the change in
the phase angle between the 2 input clocks over some convenient time
interval (e.g., 10, 100, or 1,000 seconds) and compute the frequency
difference using the formula:


Frequency Difference = [Change in Phase Angle (in degrees) / Measurement
Duration (in seconds)] X [1 / 360]

The frequency difference can then be converted to frequency accuracy
using the formula:

Accuracy = Frequency Difference / 1e7


This seems like a pretty straight forward technique.  Am I missing
something?



Charlie Myers
WA3RAD



From sar10538 at gmail.com  Sun Oct 12 00:33:15 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Sun, 12 Oct 2008 17:33:15 +1300
Subject: [time-nuts] Sulzer Labs D-5 oscillator
In-Reply-To: <E1Kootq-0002oD-Hs@febo.com>
References: <rk@timing-consultants.com>
	<995765D00C9A462CAED3D7B3FE1865C7@Robin>
	<20081011062021.61D43BCD5@ip-64-139-1-69.sjc.megapath.net>
	<F17F40AD76BA4994849B95294A8FEA55@Robin> <E1Koa4m-0006To-CA@febo.com>
	<1231b6a80810110218v699ec251ke1cff6779857ad65@mail.gmail.com>
	<E1Kob3z-0007Bt-UW@febo.com>
	<1231b6a80810111506o7b416205laf934bbae8b646a6@mail.gmail.com>
	<E1Kootq-0002oD-Hs@febo.com>
Message-ID: <1231b6a80810112133jea0e0c3m387b5348d320218a@mail.gmail.com>

Hi Mike,

2008/10/12 Mike Monett <XDE-L2G3 at myamail.com>:
>  I have been running Eagle pcb cad on Suse since 2001. I am extremely
>  happy with  linux. But LTspice requires Wine, Pimmy will run  on it,
>  and also  Hotkeyz.  This  will   tide   me  over  until  I  can find
>  replacements, but LTspice will always need Wine.

Ok, I understand the need, certainly, for LTspice. Have you looked at
the hotkey support under KDE, I know it may not be as simple and slick
as Hotkeyz but once configured it may do what you want. I'll cover
what I think you are meaning about the need for Pimmy later.

>  My friend  down  the hall keeps experimenting  with  different Linux
>  distros and  tells me about his experiences, some good and  some not
>  so good. For now, it looks like I will be running Suse and Ubuntu.

Well, we all can have bad experiences with the OS at times. I've
certainly done things that have pushed it well over the edge and it
has fallen into broken pieces but that was my fault for trying to do
something that did not work. But, whenever this has happened, I've
been able to pick up the pieces and put it back together every time,
without having to resort to getting the install disks out. And I
frequently work well beyond the bleeding-edge. It really bugs me the
times I have to completely rebuild my WinXP laptop system after
nothing more than sneezing on it. Quite how an enterprise can even
think about basing it's precious business on this completely puzzles
me but then I'm not taken in by the slick high pressure marketing
stuff. Take Nobodies Word For It is a good adage and was an excellent
Brit TV series. Carol Vordawoman, the thinking man's crumpet (sorry,
off the rails again).

>  I tried  Thunderbird some time ago, but I think I gave  up  since it
>  would not  handle multiple accounts like Pimmy does.  That  may have
>  changed.
>
>  But the  message  there  is  to go to KasMail  and  get  a  bunch of
>  disposable email addresses. Then kill any that pick up spam. But you
>  need a  client  that  takes  care of  all  the  details  in handling
>  multiple accounts,  or  you very quickly get in  a  lot  of trouble.
>  Pimmy does that very well.

OK, so you open up a bunch of tmp mail addresses and want to use them
transparently from a mail client. One obvious way is to use Gmail as
the main account and add the external KasMail mailboxes to it. You can
get Gmail to label the foreign mail addresses with their own account
name and to automatically handle the sending addresses to be the
remote mailbox on replies. When you compose a fresh thread, you just
select the sending address as you require. I use this system all the
time for the same reasons that you have stated.

It's also possible to do the same thing with Thunderbird. Just add the
external email accounts and configure it to send with a return address
of the external email box. I have no idea if these options are as
slick and easy to use as Pimmy as I have never used it.

>  I just  checked  - the last spam I got was a  phishing  email  for a
>  London bank. It was last August 14, which is two months ago.
>
>  One spam every two months is not so bad. I can handle that:)

Congratulations. Last time I looked at my Mother's email account, she
had about 1300 spam messages over the last 30 days. Yes, really! she
is hopeless, hands over her details to every Tom, Dick and Harry
despite my strong advice not to do so.

>  My preferences are stuff that works, doesn't crash and doesn't erase
>  my files.  Once  you are inside a CAD program  or  writing  code, it
>  really doesn't matter what system you are on as long as it works.

Well, not much crashes under the stable, IE. non bleeding-edge, Lunux
these days apart from the stupid Flash plugin under Firefox, I guess.
That's the thing that really bugs me.

>  I really  have no problems running Linux. I still write  most  of my
>  programs in  DOS, so commandline switches are not an  issue.  I just
>  include them  in  my programs so I don't have  to  remember  all the
>  silly options, like all the stuff you can do with PKZip.

That's what 'man command' or --help is for. Mind you that probably
does not apply in the other-world. When I stared out with UNIX there
was no X Windows, it was all command line and I'm at my most comfort
when I'm working down there too. It's certainly much more powerful
than any gui version of the application I have seen.

>  So far,  I  just  haven't  had  the time  to  sit  down  and  do the
>  conversion to  Linux.  But  now my lab is expanding,  and  I  can no
>  longer get motherboards with drivers for Win98, so I have no choice.

Cool, well it's of no loss to you, I would see it as a gain. They have
been saying that UNIX (Linux is just a clone of it) is dead since the
70's and that has kept a smile on my face for the last three decades.
Seems they may have thrown out the bathwater but the baby is still
alive and kicking.

>  And that was my message for those still hoping XP will last forever.

I think Vista will go the way that ME went but I think that XP will
last a bit longer than M$ wants it around due to industry pressure. As
for Windows 7, well that is another unknown so I don't see how people
can say that this will be the answer to all the problems. It's just
going to be millions of extra lines of bloat^H^H^H^H^Hcode and will
require heaps more power, I bet anyone.

>  It won't. Bill will see to that:)

Thought he retired :)

>  Thanks for the encouragement!

My pleasure. Now I'd better duck down for the flack that will fly
around for going so off-topic on this group. Still, I'm no the only
one, there is the sound guys thread going round at the moment.

73 and all best wishes
Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From sar10538 at gmail.com  Sun Oct 12 00:36:21 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Sun, 12 Oct 2008 17:36:21 +1300
Subject: [time-nuts] What is the best counter for a Time Nuts?
In-Reply-To: <8C1E01B3C43FF44EAC6658014AB0617A02A93905@PSCDALPEXCH03.perotsystems.net>
References: <8C1E01B3C43FF44EAC6658014AB0617A02A93905@PSCDALPEXCH03.perotsystems.net>
Message-ID: <1231b6a80810112136l16717795oe01914e5ea6ceb4@mail.gmail.com>

2008/10/12 Myers, Charlie <Charlie.Myers at ps.net>:
> Hello to the Time Nuts,
>
> I have been reading the mail on this topic for the last week or so with
> great interest.  Lots of interesting ideas have been put forth for
> measuring frequency to a high degree of precision and for comparing a 10
> MHz clock's frequency to a highly accurate 10Mhz frequency "standard".
>
> The way I measure the frequency of a 10 MHz clock is to compare it to a
> second 10MHz clock of known accuracy and stability, not only with a
> frequency counter but also with a phase meter.
>
> I have several GPS disciplined OCXO's, one GPS disciplined Rubidium
> oscillator, and several free running rubidium oscillators.  I measure
> the frequency of an unknown 10 MHz clock using a 2 step process.  First
> I measure the unknown 10 MHz clock using an HP 5384A reciprocal counter
> that employs my known 10 MHz clock as its external timebase.  I set the
> gate time to 10 seconds and the counter delivers a frequency measurement
> with a resolution of less than 3 mhz (3 millihertz).  So, assuming my
> known timebase is "bang on", I know the frequency of the unknown 10 MHz
> source to an accuracy of roughly 3e-10 or 3 parts in 10 billion.
>
> To get a more precise measurement of the frequency difference between
> the two 10 MHz clocks, I supply the known 10 MHz clock to the Channel A
> input of an HP 3575A Gain-Phase meter and the unknown 10 MHz clock to
> the channel B input of the Gain-Phase meter.  I measure the change in
> the phase angle between the 2 input clocks over some convenient time
> interval (e.g., 10, 100, or 1,000 seconds) and compute the frequency
> difference using the formula:
>
>
> Frequency Difference = [Change in Phase Angle (in degrees) / Measurement
> Duration (in seconds)] X [1 / 360]
>
> The frequency difference can then be converted to frequency accuracy
> using the formula:
>
> Accuracy = Frequency Difference / 1e7
>
>
> This seems like a pretty straight forward technique.  Am I missing
> something?

So what's time nutty about this method...

:)
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From bruce.griffiths at xtra.co.nz  Sun Oct 12 02:02:42 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Sun, 12 Oct 2008 19:02:42 +1300
Subject: [time-nuts] What is the best counter for a Time Nuts?
In-Reply-To: <1231b6a80810112136l16717795oe01914e5ea6ceb4@mail.gmail.com>
References: <8C1E01B3C43FF44EAC6658014AB0617A02A93905@PSCDALPEXCH03.perotsystems.net>
	<1231b6a80810112136l16717795oe01914e5ea6ceb4@mail.gmail.com>
Message-ID: <48F19302.1090206@xtra.co.nz>

Steve Rooke wrote:
> 2008/10/12 Myers, Charlie <Charlie.Myers at ps.net>:
>   
>> Hello to the Time Nuts,
>>
>> I have been reading the mail on this topic for the last week or so with
>> great interest.  Lots of interesting ideas have been put forth for
>> measuring frequency to a high degree of precision and for comparing a 10
>> MHz clock's frequency to a highly accurate 10Mhz frequency "standard".
>>
>> The way I measure the frequency of a 10 MHz clock is to compare it to a
>> second 10MHz clock of known accuracy and stability, not only with a
>> frequency counter but also with a phase meter.
>>
>> I have several GPS disciplined OCXO's, one GPS disciplined Rubidium
>> oscillator, and several free running rubidium oscillators.  I measure
>> the frequency of an unknown 10 MHz clock using a 2 step process.  First
>> I measure the unknown 10 MHz clock using an HP 5384A reciprocal counter
>> that employs my known 10 MHz clock as its external timebase.  I set the
>> gate time to 10 seconds and the counter delivers a frequency measurement
>> with a resolution of less than 3 mhz (3 millihertz).  So, assuming my
>> known timebase is "bang on", I know the frequency of the unknown 10 MHz
>> source to an accuracy of roughly 3e-10 or 3 parts in 10 billion.
>>
>> To get a more precise measurement of the frequency difference between
>> the two 10 MHz clocks, I supply the known 10 MHz clock to the Channel A
>> input of an HP 3575A Gain-Phase meter and the unknown 10 MHz clock to
>> the channel B input of the Gain-Phase meter.  I measure the change in
>> the phase angle between the 2 input clocks over some convenient time
>> interval (e.g., 10, 100, or 1,000 seconds) and compute the frequency
>> difference using the formula:
>>
>>
>> Frequency Difference = [Change in Phase Angle (in degrees) / Measurement
>> Duration (in seconds)] X [1 / 360]
>>
>> The frequency difference can then be converted to frequency accuracy
>> using the formula:
>>
>> Accuracy = Frequency Difference / 1e7
>>
>>
>> This seems like a pretty straight forward technique.  Am I missing
>> something?
>>     
>
> So what's time nutty about this method...
>
> :)
>   
Using ~40 year old boat anchor rackmount equipment to measure something 
that can be done more accurately with a handful Of ICs.

Bruce


From sar10538 at gmail.com  Sun Oct 12 02:20:55 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Sun, 12 Oct 2008 19:20:55 +1300
Subject: [time-nuts] What is the best counter for a Time Nuts?
In-Reply-To: <48F19302.1090206@xtra.co.nz>
References: <8C1E01B3C43FF44EAC6658014AB0617A02A93905@PSCDALPEXCH03.perotsystems.net>
	<1231b6a80810112136l16717795oe01914e5ea6ceb4@mail.gmail.com>
	<48F19302.1090206@xtra.co.nz>
Message-ID: <1231b6a80810112320ybf2cd4eu9f148a4a9f2741cb@mail.gmail.com>

2008/10/12 Bruce Griffiths <bruce.griffiths at xtra.co.nz>:
> Steve Rooke wrote:
>> 2008/10/12 Myers, Charlie <Charlie.Myers at ps.net>:
>>
>>> Hello to the Time Nuts,
>>>
>>> I have been reading the mail on this topic for the last week or so with
>>> great interest.  Lots of interesting ideas have been put forth for
>>> measuring frequency to a high degree of precision and for comparing a 10
>>> MHz clock's frequency to a highly accurate 10Mhz frequency "standard".
>>>
>>> The way I measure the frequency of a 10 MHz clock is to compare it to a
>>> second 10MHz clock of known accuracy and stability, not only with a
>>> frequency counter but also with a phase meter.
>>>
>>> I have several GPS disciplined OCXO's, one GPS disciplined Rubidium
>>> oscillator, and several free running rubidium oscillators.  I measure
>>> the frequency of an unknown 10 MHz clock using a 2 step process.  First
>>> I measure the unknown 10 MHz clock using an HP 5384A reciprocal counter
>>> that employs my known 10 MHz clock as its external timebase.  I set the
>>> gate time to 10 seconds and the counter delivers a frequency measurement
>>> with a resolution of less than 3 mhz (3 millihertz).  So, assuming my
>>> known timebase is "bang on", I know the frequency of the unknown 10 MHz
>>> source to an accuracy of roughly 3e-10 or 3 parts in 10 billion.
>>>
>>> To get a more precise measurement of the frequency difference between
>>> the two 10 MHz clocks, I supply the known 10 MHz clock to the Channel A
>>> input of an HP 3575A Gain-Phase meter and the unknown 10 MHz clock to
>>> the channel B input of the Gain-Phase meter.  I measure the change in
>>> the phase angle between the 2 input clocks over some convenient time
>>> interval (e.g., 10, 100, or 1,000 seconds) and compute the frequency
>>> difference using the formula:
>>>
>>>
>>> Frequency Difference = [Change in Phase Angle (in degrees) / Measurement
>>> Duration (in seconds)] X [1 / 360]
>>>
>>> The frequency difference can then be converted to frequency accuracy
>>> using the formula:
>>>
>>> Accuracy = Frequency Difference / 1e7
>>>
>>>
>>> This seems like a pretty straight forward technique.  Am I missing
>>> something?
>>>
>>
>> So what's time nutty about this method...
>>
>> :)
>>
> Using ~40 year old boat anchor rackmount equipment to measure something
> that can be done more accurately with a handful Of ICs.

That would surely just make it nutty then...
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From jra at febo.com  Mon Oct 13 00:58:06 2008
From: jra at febo.com (John Ackermann N8UR)
Date: Sun, 12 Oct 2008 20:58:06 -0400
Subject: [time-nuts] Test message
Message-ID: <48F29D1E.9010906@febo.com>

Just testing after moving to the new server.  Sorry for the bandwidth...

John


From dk4xp at hoffmann-hochfrequenz.de  Mon Oct 13 01:32:52 2008
From: dk4xp at hoffmann-hochfrequenz.de (dk4xp at hoffmann-hochfrequenz.de)
Date: Mon, 13 Oct 2008 03:32:52 +0200
Subject: [time-nuts] homebrew 13 dBm distribution amplifier based on
	NIST design 5 to 100 MHz
In-Reply-To: <48DD83A2.9090002@xtra.co.nz>
References: <1fkdd4p9jpu3f6sn7qmchc7n8ft7j0gaph@4ax.com>	<48D71673.8080001@xtra.co.nz>	<qlcld41iisd7o6jq43o4tpbi3bgievgr6h@4ax.com>	<48DAF2B3.9010802@xtra.co.nz>
	<8llqd4pncvdrf1ocsgjrdq15mdjjvpotqg@4ax.com>
	<48DD83A2.9090002@xtra.co.nz>
Message-ID: <0v25f458c01cc3cvn0umgmir1upge156a6@4ax.com>

I've done a redesign of the distribution amplifier without
transformers or other ferrite (apart of dc filters). This required 
2 transistor chains in parallel or 96 mA at 24V / Channel.
 
It runs quite hot but looks like it could work from KHz to 600 MHz+. 
Harmonics are down 40 dB at 250 MHz/13 dBm including SMPD signal generator
and the 54846B scope digitizers.
AF decoupling is in again as well as Bruce's base divider caps.

http://www.hoffmann-hochfrequenz.de/downloads/IMG_0499__Q73.jpg

I had quite a lot of stability problems in the last stage; 
it liked to oscillate at 1.5  to 3 GHz. I had to use 33R
base stoppers for the pnp transistors and tried a week's evenings
with Genesys to get rid of them to no avail.

I even tried 0603 base decoupling caps right _through_ the board
from the base pad to the ground plane 0.5mm / 20 mil away.
 
There is still a lot to do optimizing the voltage drops
per stage and characterizing that thing. Any idea of more
harmless pnp wideband transistors with Ptot = 1W?
Maybe I could run this with -24V and use more NPNs and the
pnp only in the CC stage.

The efficiency might be improved with a 10 uH choke from the 
final collectors to gnd. That could be accomplished without
ferrite or at least with a large air gap.

regards, Gerhard dk4xp


From VK3FGJM at commtelns.com  Mon Oct 13 01:36:23 2008
From: VK3FGJM at commtelns.com (VK3FGJM)
Date: Mon, 13 Oct 2008 12:36:23 +1100
Subject: [time-nuts] FW:  Test message
Message-ID: <A02F13E7BD2DA746B816838E9267A7AC930FFD@companyweb>

 Hi John,

5 by 9 down here.

Regards

Gerald
Vk3FGJM

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of John Ackermann N8UR
Sent: Monday, 13 October 2008 11:58 AM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] Test message

Just testing after moving to the new server.  Sorry for the bandwidth...

John

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
--
Message  protected by MailGuard: e-mail anti-virus, anti-spam and
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http://www.mailguard.com.au/mg




From XDE-L2G3 at myamail.com  Mon Oct 13 02:59:02 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Sun, 12 Oct 2008 22:59:02 -0400
Subject: [time-nuts] What is the best counter for a Time Nuts?
References: <8C1E01B3C43FF44EAC6658014AB0617A02A93905@PSCDALPEXCH03.perotsystems.net>
Message-ID: <mailman.0.1223866777.2535.time-nuts@febo.com>


  Hello Charlie,

  I am  very pleased to see your post. Measurements and good  data are
  very important, and much more valuable than handwaving.

  "Myers, Charlie" <Charlie.Myers at ps.net> wrote:

  >  Hello to the Time Nuts,

  > I have been reading the mail on this topic for the last week or so
  > with great interest. Lots of interesting ideas have been put forth
  > for measuring  frequency  to a high degree  of  precision  and for
  > comparing a  10 MHz clock's frequency to a  highly  accurate 10Mhz
  > frequency "standard".

  > The way I measure the frequency of a 10 MHz clock is to compare it
  > to a second 10MHz clock of known accuracy and stability,  not only
  > with a frequency counter but also with a phase meter.

  This is excellent procedure. Cross-checking is always a good idea. I
  try to  find as many ways to measure something as  possible.  If one
  measurement doesn't  agree  with the others, it  shows  something is
  wrong somewhere. So this is not a boring or stupid waste of time. It
  is essential.

  > I have  several  GPS   disciplined   OCXO's,  one  GPS disciplined
  > Rubidium    oscillator,   and   several   free   running  rubidium
  > oscillators. I  measure the frequency of an unknown  10  MHz clock
  > using a 2 step process.

  What are  the models? What GPS card are you using, and  how  are you
  locking to it?

  > First I  measure  the  unknown  10 MHz  clock  using  an  HP 5384A
  > reciprocal counter  that  employs  my known 10  MHz  clock  as its
  > external timebase.  I  set  the gate time to  10  seconds  and the
  > counter delivers a frequency measurement with a resolution of less
  > than 3 mhz (3 millihertz).

  Do you  happen  to know any source for the manual?  There  is almost
  nothing on the web.

  > So, assuming my known timebase is "bang on", I know  the frequency
  > of the unknown 10 MHz source to an accuracy of roughly 3e-10  or 3
  > parts in 10 billion.

  > To get  a  more precise measurement  of  the  frequency difference
  > between the two 10 MHz clocks, I supply the known 10 MHz  clock to
  > the Channel  A  input  of an HP  3575A  Gain-Phase  meter  and the
  > unknown 10  MHz  clock to the channel B  input  of  the Gain-Phase
  > meter.

  Another very  difficult instrument to find any data on.  The  best I
  could find shows it has an accuracy of +/- 0.5 degree and resolution
  of 0.1 degree.

  I think in this case the resolution parameter might be quite valid.

  You are  measuring a small change, not an absolute value.  So  if it
  stable, I'd consider keeping it.

  > I measure the change in the phase angle between the 2 input clocks
  > over some convenient time interval (eg, 10, 100, or 1,000 seconds)
  > and compute the frequency difference using the formula:

  > Frequency Difference  =  [Change  in Phase  Angle  (in  degrees) /
  > Measurement Duration (in seconds)] X [1 / 360]

  > The frequency  difference  can   then  be  converted  to frequency
  > accuracy using the formula:

  >  Accuracy = Frequency Difference / 1e7

  > This seems like a pretty straight forward technique. Am  I missing
  > something?

  >  Charlie Myers
  >  WA3RAD

  Charlie, this could be quite significant. A cross-check on your math
  shows 1  degree  at  10MHz  is   1e-7  /  360  =  2.77e-10s,  or 277
  picoseconds. That's not bad at all.

  In 1000 seconds, you could resolve 2.77e-10 / 1e3 = 2.77e-13. That's
  pretty good.  1000  seconds  is only 16.6  minutes,  which  is quite
  reasonable. And that's truncating the resolution to 1 degree.

  24 hrs  would get you to 2.77e-10 / (24 * 3600) = 3.2e-15,  which is
  very acceptable. That puts you in the big leagues.

  Now comes the big question - what kind of data do you get?

  Can you give some examples of the measurements you have made?

  Can you see any drift in the GPS time?

  Thanks again very much for your post!

  Best Regards,

  Mike Monett


From tvb at LeapSecond.com  Mon Oct 13 03:19:42 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Sun, 12 Oct 2008 20:19:42 -0700
Subject: [time-nuts] Testing frequency using NTP Bruce GPS ps
References: <mailman.195.1222952732.2205.time-nuts@febo.com><E1KlOmJ-0007rp-88@febo.com>
	<48E52F08.8070400@xtra.co.nz><E1KlwtS-0002lT-Ek@febo.com>
	<000f01c925cd$e6c84de0$0300a8c0@pc52><E1KlyXH-0004HB-SC@febo.com>
	<005401c925f2$db402fe0$0300a8c0@pc52> <E1KnqaY-0005xh-W5@febo.com>
Message-ID: <000701c92ce2$8d792e50$0700a8c0@pc52>

Mike,
Comments below...

>  I have to learn more about how you do your measurements. A 53132A is
>  way out  of  my price range at the moment. But I  do  have  a 53310A
>  which should give comparable results.

Yes, if you can get a clean series of 1PPS sub-ns time interval
measurements over GPIB from your 53310A then you're all set.
What time/frequency reference do you have available against
which to compare your GPS receiver?

>  I am interested in learning more about these errors. Is there a list
>  somewhere that describes the sources of error, and what can  be done
>  to reduce it? I keep coming across hints of doing this  in software,
>  but it would seem that has to be done in the signal  processing part
>  of the receiver. But we don't have access to that. Is there anything
>  else we can do to help remove some of these errors?

This is a large topic. Google for words: gps error budget
and you'll begin your long journey. Also look for topics like
ionosphere multipath troposphere ephemeris. A typical OEM
GPS receiver board will get you within 100 ns of UTC without
much effort. Here's a couple of pages to get you started:

http://edu-observatory.org/gps/gps_accuracy.html
http://www.trimble.com/gps/howgps-error2.shtml
http://www.cmtinc.com/gpsbook/chap6.html
http://www.ias.ac.in/currsci/oct102007/927.pdf
http://www.usace.army.mil/publications/eng-manuals/em1110-1-1003/c-4.pdf
http://seismo.berkeley.edu/~battag/GAMITwrkshp/lecturenotes/unit1/unit1.html

>  That is very interesting. What do you mean by granularity? I  have a
>  file somewhere  that  talks about the algorithm to  select  the next
>  1PPS pulse.  It added 500ps to the rounding, so the result  would be
>  on 1 ns boundaries. Is that what you meant?

Your GPS receiver outputs a correction value in fixed integer
units of ns; no less. Other words loosely used on this context
are resolution or quantum or precision.

>  That is getting very subtle. How much effect does it have, and where
>  on earth do you learn all this stuff?

When you write your software to correct sawtooth errors you'll
see where GPS or TIC sign errors and off-by-one sample errors
can bite you. Not all receivers do it the same way, either, so
make sure to study the manual(s).

/tvb



From XDE-L2G3 at myamail.com  Mon Oct 13 03:23:15 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Sun, 12 Oct 2008 23:23:15 -0400
Subject: [time-nuts] Lassen IQ receiver APRS beacon pictures
References: <001901c92b4a$217b9010$ad00a8c0@Morris1>
	<b3bd5fcb0810102158v4bb1f1e1u7c85ddf21ac51478@mail.gmail.com>
	<E1KoY9X-0005J0-Sk@febo.com>
	<b3bd5fcb0810110840v35e81cc3g239ca77b5c402006@mail.gmail.com>
Message-ID: <mailman.1.1223868229.2535.time-nuts@febo.com>

  Hi Robert

  "Robert Darlington" <rdarlington at gmail.com> wrote:

  > Hi Mike,  I'll  answer  the  questions  in  line  with  your email
  > message, below.

  [...]

  >> These units look interesting. Do you mind if I ask some questions?

  >> 1. What kind of non-time keeping uses have you found for them?

  > The first  project was an APRS beacon for a high  altitude balloon
  > project which  hasn't launched yet, but was tested in my  car. The
  > last project  was  for  the  local  laboratory.  They  developed a
  > sampling system which had every gadget but the kitchen sink in it,
  > and every  part was made out of unobtanium. In this  case  the gps
  > board had been discontinued for about 4 years so I had to design a
  > new one  that would be the same physical size, same  hole spacing,
  > and same pinout.

  That is very interesting. Making things fit can be fun!

  > I figured  if I was going to do this and have a minimum  run  of 5
  > boards, I was going to make 2 for me (they needed 3 total). In the
  > picture you'll  see the top half with the GPS module  has  a white
  > box around  it.  This  part I cut off  after  programming  the GPS
  > receiver modules  and installed in their gadget, the  rest  of the
  > board gave me a MAX232 (3.3 volt version if I remember  right) and
  > broke out  both  serial ports to DB9 for easy hookup  to  a  PC. I
  > should've added a PPS line but was too concerned with  keeping the
  > board working  when  I cut it in half to really  think  about more
  > than what  they  needed.  What you can't see  is  the  button cell
  > battery on the back for retaining constellation data

  Too bad  about losing the 1PPS. Maybe you can persuade  them  to get
  some spares.

  >  Here's the board: http://www.losalamostech.com/gps_board.jpg

  Thanks - that gives a good idea how bug the GPS is.

  But don't the connectors add a lot of weight?

  > Here's their gadget:

  >http://www.lanl.gov/orgs/tt/pdf/techs/hands_off_gun.pdf

  Shades of Star Trek. We can see it happening right before our eyes.

  >> 2. How  well  do  they work indoors? Do you  have  to  be  near a
  >> window? What about inside a multi-story building?

  > We only  tried  it  outside. Their  gadget  got  the  short little
  > ceramic patch  antenna.  I used the longer (5 meter  I  think) mag
  > mount version in my car when testing the APRS beacon.

  I wonder  about  the  GPS chips used in  cellphones.  Would  they be
  suitable for this project? They might save some weight.

  >> 4. Have  you ever taken the shield off and looked  inside?  If so,
  >> can you  see the crystal oscillator and tell whether it is  a bare
  >> crystal or a complete oscillator module?

  > No, but it comes off easy enough when not soldered down.  I'll try
  > to pop mine open and take some pictures of the guts for  you later
  > today.

  Thanks, I would really appreciate that.

  >> 5. How  much  do  they cost? Do you know of  any  others  that are
  >> cheaper?

  > We paid  somewhere  on the order of $50  +  the  antenna. Sparkfun
  > sells them here for $56:

  >  http://www.sparkfun.com/commerce/product_info.php?products_id=163

  Great - thanks for the link.

  > They also sell the antennas and breakout boards that  already have
  > the tiny  little surface mount sockets (I have a few  left  if you
  > end up buying one of these).

  I'm very  interested  in antennas these days. I  know  nothing about
  them, but  find they can have a lot to do with time errors.  Such as
  multipath from passing cars.

  What happens if a pigeon sits on your GPS antenna?

  > The really  interesting thing is that the manual  states  that the
  > PPS output  is  within  50ns of reality. I plan  on  using  one to
  > discipline that  Efratom  rubidium  standard  I  was  asking about
  > earlier in  the  week.  By  the  way,  the  connector  from Mouser
  > electronics came in and I'm ready to go, just waiting on  the part
  > to come in from China.

  Me too! I just got news that my rubidium has already  shipped, which
  is surprising. PayPal hasn't cleared yet, so I guess he has a lot of
  confidence in the system.

  Which Efratom do you have? And who are you dealing with in China?

  >  -Bob

  >> Thanks for your help!

  Best Regards,

  Mike Monett


From XDE-L2G3 at myamail.com  Mon Oct 13 03:27:29 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Sun, 12 Oct 2008 23:27:29 -0400
Subject: [time-nuts] Lassen IQ receiver
References: <mailman.406.1223714630.2205.time-nuts@febo.com>
	<002201c92b9a$14f68cf0$ad00a8c0@Morris1>
Message-ID: <mailman.2.1223868471.2535.time-nuts@febo.com>


  "Morris Odell" <vilgotch at bigpond.net.au> wrote:

  >  Hi Mike,

  > The Lassen  IQ is a little PCB mounted 12  channel  receiver about
  > half the  size  of   a   matchbox,   which   is  intended  for OEM
  > applications. It's not easy to open to see what's inside.  It uses
  > tiny surface  mount  connectors  to get  signals  in  and  out but
  > there's no access to the oscillator if you want to use an external
  > osc. It doesn't have a built in antenna so the performance depends
  > on the  external  antenna  connected to  it.  It  seems  to handle
  > constellation changes  quite  well  as   far  as  I  can  see. The
  > application info  says  it can be used for navigation  as  well as
  > timekeeping.

  Thanks - that is good info.

  > It has  2 serial ports as well as a 1 pps output. One  serial port
  > is used  to  control  and  read  it  using  Trimble's  TSIP binary
  > protocol.

  > There is  free DOS and Windows software available from  Trimble to
  > do this.  The  other port can be configured to use  TSIP,  NMEA or
  > Trimble's own ASCII protocol called TAIP.

  Very very good info. Thanks.

  > I paid  AU$70 about 2 years ago, which at the time  was equivalent
  > to about US$60. You could probably do better these days.  I bought
  > a bunch  of old 6 channel VP Oncore receivers about a year  ago on
  > ebay for  AU12  each. They are ideal  for  timing  aplications and
  > clocks.

  I couldn't seem to find any VP, so I got two UP+. Are they usable?

  >  HTH,

  >  Morris

  Thanks for your help.

  Best Regards,

  Mike Monett


From XDE-L2G3 at myamail.com  Mon Oct 13 03:56:31 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Sun, 12 Oct 2008 23:56:31 -0400
Subject: [time-nuts] Testing frequency using NTP Bruce GPS ps
References: <mailman.195.1222952732.2205.time-nuts@febo.com>
	<E1KlOmJ-0007rp-88@febo.com> <48E52F08.8070400@xtra.co.nz>
	<E1KlwtS-0002lT-Ek@febo.com> <000f01c925cd$e6c84de0$0300a8c0@pc52>
	<E1KlyXH-0004HB-SC@febo.com> <005401c925f2$db402fe0$0300a8c0@pc52>
	<E1KnqaY-0005xh-W5@febo.com> <000701c92ce2$8d792e50$0700a8c0@pc52>
Message-ID: <mailman.3.1223870215.2535.time-nuts@febo.com>


  "Tom Van Baak" <tvb at LeapSecond.com> wrote:

  >Mike,

  > Comments below.

  >> I have to learn more about how you do your measurements. A 53132A
  >> is way  out  of  my price range at the moment. But  I  do  have a
  >> 53310A which should give comparable results.

  > Yes, if  you can get a clean series of 1PPS  sub-ns  time interval
  > measurements over GPIB from your 53310A then you're all set.

  No luck. It is very good for looking at PLL loop dynamics,  which is
  the reason I bought it.

  But it doesn't seem to be useful for Allan variance, so I'll have to
  make my own system. I'll use the digital mixer I posted earlier.

  > What time/frequency reference do you have available  against which
  > to compare your GPS receiver?

  I ordered a rubidium, two OCXO's, and two Oncore UT Plus GPS cards.

  I plan on making a standard 1PPS phase/frequency detector to lock to
  the 1PPS.

  The second version will use the same model GPS card, but it will use
  a new method of locking to the 1PPS.

  I'll compare  the  results with the rubidium  and  OCXO's  locked to
  either GPS.

  >> I am  interested in learning more about these errors. Is  there a
  >> list somewhere that describes the sources of error, and  what can
  >> be done to reduce it? I keep coming across hints of doing this in
  >> software, but  it  would seem that has to be done  in  the signal
  >> processing part  of  the receiver. But we  don't  have  access to
  >> that. Is  there  anything else we can do to help  remove  some of
  >> these errors?

  > This is  a  large topic. Google for words:  gps  error  budget and
  > you'll begin  your  long   journey.   Also  look  for  topics like
  > ionosphere multipath  troposphere  ephemeris.  A  typical  OEM GPS
  > receiver board  will  get you within 100 ns  of  UTC  without much
  > effort. Here's a couple of pages to get you started:

  >http://edu-observatory.org/gps/gps_accuracy.html
  >http://www.trimble.com/gps/howgps-error2.shtml
  >http://www.cmtinc.com/gpsbook/chap6.html
  >http://www.ias.ac.in/currsci/oct102007/927.pdf
  >http://www.usace.army.mil/publications/eng-manuals/em1110-1-1003/c-4.pdf
 
>http://seismo.berkeley.edu/~battag/GAMITwrkshp/lecturenotes/unit1/unit1.html

  Thanks very  much  for  the links.  That  information  will  be very
  helpful.

  [...]

  > Your GPS  receiver  outputs a correction  value  in  fixed integer
  > units of ns; no less. Other words loosely used on this context are
  > resolution or quantum or precision.

  Now I am confused. I thought it used the internal crystal  clock for
  the timing,  and  selected which pulse to output for  the  1PPS, and
  this is what causes the sawtooth. If so, the timing is determined by
  the crystal.

  [...]

  > When you write your software to correct sawtooth errors you'll see
  > where GPS or TIC sign errors and off-by-one sample errors can bite
  > you. Not all receivers do it the same way, either, so make sure to
  > study the manual(s).

  I don't use software to correct the sawtooth. It is a whole  new way
  of locking to the 1PPS.

  A lot of the errors will simply vanish. But I'll still be vulnerable
  to ionosphere  delay, constellation changes, and pigeons  sitting on
  the antenna.

  >/tvb

  Thanks for your help!

  Best Regards,

  Mike Monett


From tvb at LeapSecond.com  Mon Oct 13 04:22:18 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Sun, 12 Oct 2008 21:22:18 -0700
Subject: [time-nuts] Testing frequency using NTP Bruce GPS ps
References: <mailman.195.1222952732.2205.time-nuts@febo.com><E1KlOmJ-0007rp-88@febo.com>
	<48E52F08.8070400@xtra.co.nz><E1KlwtS-0002lT-Ek@febo.com>
	<000f01c925cd$e6c84de0$0300a8c0@pc52><E1KlyXH-0004HB-SC@febo.com>
	<005401c925f2$db402fe0$0300a8c0@pc52><E1KnqaY-0005xh-W5@febo.com>
	<000701c92ce2$8d792e50$0700a8c0@pc52>
	<E1KpEYA-0005hN-W1@meow.febo.com>
Message-ID: <00e501c92ceb$4a6d17d0$0700a8c0@pc52>

>  Now I am confused. I thought it used the internal crystal  clock for
>  the timing,  and  selected which pulse to output for  the  1PPS, and
>  this is what causes the sawtooth. If so, the timing is determined by
>  the crystal.

Correct. For example, if the xtal were 20.00 MHz then the hardware
timing pulse could be off by up to +/- 25.00 ns from the nominal
value. But the firmware knows approximately how far off, and so
it outputs this value as a correction message. The correction is
not perfect, but if used, is always better than hardware alone.

>  I don't use software to correct the sawtooth. It is a whole  new way
>  of locking to the 1PPS.

You might want to check out James Miller's excellent GPSDO.
His simple design also does not use sawtooth correction and
the results are very good. See:

http://www.jrmiller.demon.co.uk/projects/ministd/frqstd.htm
http://www.leapsecond.com/pages/gpsdo/
http://www.febo.com/pages/oscillators/g3ruh_gpsdo/

/tvb



From tvb at LeapSecond.com  Mon Oct 13 04:36:50 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Sun, 12 Oct 2008 21:36:50 -0700
Subject: [time-nuts] What is the best counter for a Time Nuts?
References: <8C1E01B3C43FF44EAC6658014AB0617A02A93905@PSCDALPEXCH03.perotsystems.net>
	<E1KpDek-0004sh-0v@meow.febo.com>
Message-ID: <00ea01c92ced$53d3cab0$0700a8c0@pc52>

> This seems like a pretty straight forward technique. Am  I missing
> something?

Hi Charlie,

Nope, your basic method of measuring frequency *accuracy*
with two phase angle measurements is fine. I think many of us
do the same, one way or another. Relative frequency error is,
after all, just a measure of _phase_ drift over time. So you're
good to go.

One has to be careful, though, not to claim more accuracy than
is fair. Once you take into account
    the instability of your unit under test,
    the resolution and stability of the phase comparator itself,
    and the accuracy and stability of the frequency reference,
you may find that your accuracy method is slightly less precise
than the simple math suggests.

Going one step further, note that measuring frequency *stability* 
is essentially taking multiple frequency accuracy measurements
and statistically looking at _frequency_ drift over time.

>  24 hrs  would get you to 2.77e-10 / (24 * 3600) = 3.2e-15,  which is
>  very acceptable. That puts you in the big leagues.

Hi Mike,

It doesn't quite work this way. If it did, hey, you could wait a
month, and be better than the big leagues!

The missing consideration is the stability of the test setup. The
frequency reference and the phase comparator would have to
have 10^-15 levels of stability before you could claim this sort
of per-day measurement resolution. I can tell you a telecom
rubidium and hp3575A are not even close to this.

>  Can you see any drift in the GPS time?

You're not likely to see "drift in GPS time" when using a free
running rubidium or another GPSDO as a reference. Do you
see why?

/tvb




From rdarlington at gmail.com  Mon Oct 13 05:21:48 2008
From: rdarlington at gmail.com (Robert Darlington)
Date: Sun, 12 Oct 2008 23:21:48 -0600
Subject: [time-nuts] Lassen IQ receiver APRS beacon pictures
In-Reply-To: <E1KpE2A-0005GO-LB@meow.febo.com>
References: <001901c92b4a$217b9010$ad00a8c0@Morris1>
	<b3bd5fcb0810102158v4bb1f1e1u7c85ddf21ac51478@mail.gmail.com>
	<E1KoY9X-0005J0-Sk@febo.com>
	<b3bd5fcb0810110840v35e81cc3g239ca77b5c402006@mail.gmail.com>
	<E1KpE2A-0005GO-LB@meow.febo.com>
Message-ID: <b3bd5fcb0810122221y6e35dd06t9e08e7940713481d@mail.gmail.com>

On Sun, Oct 12, 2008 at 9:23 PM, Mike Monett <XDE-L2G3 at myamail.com> wrote:

<snip?

   Too bad  about losing the 1PPS. Maybe you can persuade  them  to get
some spares.

I added the PPS line today.  2 wires off the connector (PPS and ground) to
an SMA connector and some epoxy.  It took 10 minutes but wish I thought to
add it from the get go.


>  >  Here's the board: http://www.losalamostech.com/gps_board.jpg
>
>  Thanks - that gives a good idea how bug the GPS is.
>
>  But don't the connectors add a lot of weight?
>

It adds some weight.  I have another board with a Lassen SQ receiver that
I'll probably end up using for the balloon project.


>
>  > Here's their gadget:
>
>  >http://www.lanl.gov/orgs/tt/pdf/techs/hands_off_gun.pdf
>
>  Shades of Star Trek. We can see it happening right before our eyes.


Yep, and it was designed nearly 5 years ago.  My company got the contract to
clone the device and design/build anything that was impossible to find.  Our
clones were sent out as demo units by the technology transfer group at the
lab.  I guess it's so companies can license the technology and develop
commercial units.  We made one clear, and one transparent blue.  The most
fun was polishing up the parts that were made on an ObJet printer.  They
were yellow but polished up clear.  Very cool.


>
>  >> 2. How  well  do  they work indoors? Do you  have  to  be  near a
>  >> window? What about inside a multi-story building?
>

I've been running it for the past 24 hours with the antenna in a west facing
window.  I'm picking up 4-5 satellites and only getting a 2D fix.  6 allows
for a 3D fix, but it might be more of a reception issue than number of
satellites.  I would think 4 would be sufficient.

<snip>


>  >> 4. Have  you ever taken the shield off and looked  inside?  If so,
>  >> can you  see the crystal oscillator and tell whether it is  a bare
>  >> crystal or a complete oscillator module?
>

http://www.nerdhouse.org/gallery/v/gps

<snip>

 I'm very  interested  in antennas these days. I  know  nothing about
>  them, but  find they can have a lot to do with time errors.  Such as
>  multipath from passing cars.
>
>  What happens if a pigeon sits on your GPS antenna?
>

I imagine that it would attenuate the signal sufficiently to lose a fix, but
the realtime clock would take over.  I setup the Lassen iQ to only give a
PPS signal when it has a satellite fix so in this case, it should stop.

  > The really  interesting thing is that the manual  states  that the
>  > PPS output  is  within  50ns of reality. I plan  on  using  one to
>  > discipline that  Efratom  rubidium  standard  I  was  asking about
>  > earlier in  the  week.  By  the  way,  the  connector  from Mouser
>  > electronics came in and I'm ready to go, just waiting on  the part
>  > to come in from China.
>
>  Me too! I just got news that my rubidium has already  shipped, which
>  is surprising. PayPal hasn't cleared yet, so I guess he has a lot of
>  confidence in the system.
>
>  Which Efratom do you have? And who are you dealing with in China?
>

It's an Efratom FRS-C purchased on eBay from "fluke.l",
http://myworld.ebay.com/fluke.l/   He's got nearly 500 positive feedback
ratings so I figure it's a good risk.   $100 delivered.

A couple weeks ago I picked up an HP time mark generator for calibrating my
oscilloscopes.  It has a 10MHz TCXO inside but can accept an external 10MHz
reference source.  Buttons on the front divide the signal, there's also an
amplifier built in, etc.  So before adjusting anything on the scope, but
after hooking it up and playing with it, I started wondering how accurate it
was -nevermind the parallax error associated with using my Mk. I eyeball
viewing the CRT!   Then I started thinking about calibrating it against
another time mark generator I had in the cabinet and wondered how I could
know if that was accurate.  Then I started thinking about how I could trust
any clocks and to what precision I need for my measurements.  I guess I
caught the bug late in the game but when I got it, it hit rather fast.
Today I was questioning why the PPS period of this GPS was reading
1.000002527 seconds (it was fluctuating by about 300ns too!) on an HP
frequency counter from the 80s.  Using the PPS signal to gate it I was
getting 10,000,0025 to 10,000,027 counts pretty consistantly using the
internal 10MHz source.  Sounds like it needs adjustment, but I don't dare
fiddle with it till I feel a lot more comfortable in this area.

The good news?   Both the time mark generator and the frequency counter will
accept a 10MHz source.   The Efratom unit spits out a 10MHz TTL signal that
should be just fine, especially after using a GPS PPS signal for feedback.
I have a lot to learn in this area but thankfully my business partner knows
a lot about this stuff.  He was one of the Navy/DoD electronics weenies that
serviced *the* clocks and was responsible for portable units in case ground
stations were destroyed.  This would allow for surface fleets to contact
subs, and military coordination in general in the case of nuclear war.  A
true keeper of the time during the late 80s early 90s.

-Bob

From kyrrin at bluefeathertech.com  Mon Oct 13 06:07:18 2008
From: kyrrin at bluefeathertech.com (Bruce Lane)
Date: Sun, 12 Oct 2008 23:07:18 -0700
Subject: [time-nuts] New servers
Message-ID: <200810122307180861.8158C2A3@192.168.42.129>

	I just found a bunch of 'Reject' entries in our mail system's log relating to the time-nuts list. The reason for the rejections is that the new list server appears to be based with a company called Server Beach.

	The reason Server Beach was blocked is because they did, at one time, have a long and sordid history of supporting spammers. I will grant that I have not seen a spam attempt from them in some time. Perhaps they cleaned up their act, finally?

	I've punched a hole in the filters for now, specifically to allow meow.febo.com through, but I'm wondering two things.

	(1) Please confirm: Is time-nuts, in fact, now permanently based out of Server Beach IP space, or is that a temporary assignment?

	(2) Will the list drop my subscription because of the rejects? There were quite a few of them.

	Thanks.


-=-=-=-=-=-=-=-=-=-=-=-
Bruce Lane, Owner & Head Hardware Heavy,
Blue Feather Technologies -- http://www.bluefeathertech.com
kyrrin (at) bluefeathertech do/t c=o=m
"Quid Malmborg in Plano..."



From Paul.Reeves at uk.thalesgroup.com  Mon Oct 13 07:24:09 2008
From: Paul.Reeves at uk.thalesgroup.com (Reeves Paul)
Date: Mon, 13 Oct 2008 08:24:09 +0100
Subject: [time-nuts] Sulzer Labs D-5 oscillator
Message-ID: <8E8D23D235D70840B6582917DF27898006935BCE@temps153538.tms-ltd.com>

Hi Tom, all,

Sorry, the D-5 is a rectangular solid, 4"x4"x7", quite featureless except
for the nameplate on the top and the connection pins, circular ~14pin, octal
size (possibly a valve - sorry, 'tube' - base, on the bottom. I will try to
get a couple of pictures off to the group within the next few days.
I have a 5.0C like the one in the reference - a very nice performing unit,
compares nicely with homebuilt GPSDO and off-air MSF standards. When the 'D'
model was offered by a friend I snapped it up - anything by Sulzer was good!
Apologies for the 'legalese' fluff that appears at the end - my employers
apparently have several lawyers with nothing important to do........

regards,
Paul     G8GJA


-----Original Message-----
From: Tom Van Baak [mailto:tvb at LeapSecond.com]
Sent: 10 October 2008 15:17
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Sulzer Labs D-5 oscillator


> Hi all,
> 
> I need a bit of help getting an old Sulzer D-5 5MHz oscillator to work. It
> was built into a rack module with monitoring facilities and had been
> slightly 'got-at' by the previous owner. Some of the connections were
> pencilled on the case but not enough to give confidence about powering it
> up. Has anybody got any information on this 'classic' design? Pin
connection
> data would be a great help, anything more would be wonderful!!
> 
> Thanks in advance,
> 
> Paul Reeves,    G8GJA

Does it look like either of these?

http://leapsecond.com/museum/sul25-1/
http://leapsecond.com/museum/sul25-2/

/tvb


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From XDE-L2G3 at myamail.com  Mon Oct 13 07:38:53 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Mon, 13 Oct 2008 03:38:53 -0400
Subject: [time-nuts] What is the best counter for a Time Nuts?
References: <8C1E01B3C43FF44EAC6658014AB0617A02A93905@PSCDALPEXCH03.perotsystems.net>
	<E1KpDek-0004sh-0v@meow.febo.com>
	<00ea01c92ced$53d3cab0$0700a8c0@pc52>
Message-ID: <mailman.4.1223883555.2535.time-nuts@febo.com>

  "Tom Van Baak" <tvb at LeapSecond.com> wrote:

  >> 24 hrs  would get you to 2.77e-10 / (24 * 3600) =  3.2e-15, which
  >> is very acceptable. That puts you in the big leagues.

  >Hi Mike,

  > It doesn't  quite work this way. If it did, hey, you could  wait a
  > month, and be better than the big leagues!

  > The missing consideration is the stability of the test  setup. The
  > frequency reference  and the phase comparator would  have  to have
  > 10^-15 levels  of  stability before you could claim  this  sort of
  > per-day measurement resolution. I can tell you a  telecom rubidium
  > and hp3575A are not even close to this.

  I know. All I was saying is he could resolve a  frequency difference
  of 3.2e-15 in 24 hours. That is big league stuff.

  As you  point  out, that is far better than  the  oscillators  he is
  using. So  his  method  is valid, and his  equipment  is  capable of
  making useful  and important measurements. Since it is  a completely
  different method, it would give a valuable cross-check against other
  methods.

  As far as the measurement stability, the phase measurement is merely
  measuring the  time between two signals. I would expect  HP  to hold
  much better than 0.1 degree with no problems. Since it  is measuring
  a relatively small change and not an absolute value,  the resolution
  of 0.1 degree could be considered valid data.

  So his equipment is capable of resolving a frequency difference that
  is much smaller than the stability of the oscillators. That is good.

  But we don't know what would happen during a 24 hour run. So  what I
  was hoping for was a table of phase angle measurements perhaps every
  15 minutes for the first several hours to get a feeling for  the ups
  and downs  of the phase angle drift, then perhaps every  hour  for a
  couple of days. That would be very valuable data.

  >> Can you see any drift in the GPS time?

  > You're not  likely  to see "drift in GPS time" when  using  a free
  > running rubidium or another GPSDO as a reference. Do you see why?

  Sorry, badly  worded. I thought he locked the rubidium  to  gps, and
  was wondering  if he monitored the DC error to the rubidium,  and if
  he saw any diurnal change.

  If so, that would indicate the rubidium is quite stable by itself.

  >/tvb

  Best Regards,

  Mike Monett


From XDE-L2G3 at myamail.com  Mon Oct 13 07:58:43 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Mon, 13 Oct 2008 03:58:43 -0400
Subject: [time-nuts] Testing frequency using NTP Bruce GPS ps
References: <mailman.195.1222952732.2205.time-nuts@febo.com>
	<E1KlOmJ-0007rp-88@febo.com> <48E52F08.8070400@xtra.co.nz>
	<E1KlwtS-0002lT-Ek@febo.com> <000f01c925cd$e6c84de0$0300a8c0@pc52>
	<E1KlyXH-0004HB-SC@febo.com> <005401c925f2$db402fe0$0300a8c0@pc52>
	<E1KnqaY-0005xh-W5@febo.com> <000701c92ce2$8d792e50$0700a8c0@pc52>
	<E1KpEYA-0005hN-W1@meow.febo.com>
	<00e501c92ceb$4a6d17d0$0700a8c0@pc52>
Message-ID: <mailman.5.1223884747.2535.time-nuts@febo.com>

  "Tom Van Baak" <tvb at LeapSecond.com> wrote:

  >> Now I  am confused. I thought it used the internal  crystal clock
  >> for the timing, and selected which pulse to output for  the 1PPS,
  >> and this  is  what  causes the sawtooth.  If  so,  the  timing is
  >> determined by the crystal.

  > Correct. For example, if the xtal were 20.00 MHz then the hardware
  > timing pulse  could be off by up to +/- 25.00 ns from  the nominal
  > value. But the firmware knows approximately how far off, and so it
  > outputs this value as a correction message. The correction  is not
  > perfect, but if used, is always better than hardware alone.

  So where did the 1ns granularity come in?

  >> I don't  use software to correct the sawtooth. It is a  whole new
  >> way of locking to the 1PPS.

  > You might want to check out James Miller's excellent GPSDO.

  > His simple  design also does not use sawtooth  correction  and the
  > results are very good. See:

  >http://www.jrmiller.demon.co.uk/projects/ministd/frqstd.htm
  >http://www.leapsecond.com/pages/gpsdo/
  >http://www.febo.com/pages/oscillators/g3ruh_gpsdo/

  Thanks, already studied and analyzed. He uses an XOR phase detector,
  but the  funny hump at 1,000 seconds bothers me. I can't see  a good
  reason for  that.  The drop starting at 1e4 is  interesting,  and it
  would have been nice to see what happens further out.

  His results also show that some other methods  using phase/frequency
  detectors are  badly implemented. That is to be expected.  PLL's are
  tough for people not used to working with noise and crosstalk.

  >/tvb

  Best Regards,

  Mike Monett


From jra at febo.com  Mon Oct 13 13:30:11 2008
From: jra at febo.com (John Ackermann N8UR)
Date: Mon, 13 Oct 2008 09:30:11 -0400
Subject: [time-nuts] New servers
In-Reply-To: <200810122307180861.8158C2A3@192.168.42.129>
References: <200810122307180861.8158C2A3@192.168.42.129>
Message-ID: <48F34D63.8040205@febo.com>

Yes, we're now running on a dedicated server at ServerBeach, which is
also where tapr.org has been hosted for two or three years (and we've
had very good luck with them).

I'm not sure where your info came from, but ServerBeach (these days,
anyway) appears to be very reputable.  They're owned by Peer One.  They
also were the original hosting company for YouTube (until Google bought
them).

I did a quick search on "ServerBeach" and "spam" and the top relevant
hit was an article from 2003 when SB shut down a customer in response to
SPEWS complaints, which took down a bunch of innocent sites; it was
reported in the NY Times.

The mailing list software does unsubscribe after a number of bounces,
but it uses an algorithm that requires more than a short outage, so you
should be OK.  But if you receive an unsubscribe notice, you can
resubscribe -- it won't prevent that.

John
----

Bruce Lane said the following on 10/13/2008 02:07 AM:
> 	I just found a bunch of 'Reject' entries in our mail system's log relating to the time-nuts list. The reason for the rejections is that the new list server appears to be based with a company called Server Beach.
> 
> 	The reason Server Beach was blocked is because they did, at one time, have a long and sordid history of supporting spammers. I will grant that I have not seen a spam attempt from them in some time. Perhaps they cleaned up their act, finally?
> 
> 	I've punched a hole in the filters for now, specifically to allow meow.febo.com through, but I'm wondering two things.
> 
> 	(1) Please confirm: Is time-nuts, in fact, now permanently based out of Server Beach IP space, or is that a temporary assignment?
> 
> 	(2) Will the list drop my subscription because of the rejects? There were quite a few of them.
> 
> 	Thanks.
> 
> 
> -=-=-=-=-=-=-=-=-=-=-=-
> Bruce Lane, Owner & Head Hardware Heavy,
> Blue Feather Technologies -- http://www.bluefeathertech.com
> kyrrin (at) bluefeathertech do/t c=o=m
> "Quid Malmborg in Plano..."
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 
> 



From wa9msd at ggnet.net  Mon Oct 13 15:11:38 2008
From: wa9msd at ggnet.net (Joseph Grossbauer)
Date: Mon, 13 Oct 2008 10:11:38 -0500
Subject: [time-nuts] New servers
In-Reply-To: <48F34D63.8040205@febo.com>
Message-ID: <A7218DBB413846DCA8C502833E9D940D@joesworkstation>

As a system administrator I'm not a big fan of Server Beach because of their
letting spammers slide but I did check the IP address of the list on
mxtoolbox.com and it came up perfectly clean.

Joe, WA9MSD

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of John Ackermann N8UR
Sent: Monday, October 13, 2008 08:30
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] New servers

Yes, we're now running on a dedicated server at ServerBeach, which is
also where tapr.org has been hosted for two or three years (and we've
had very good luck with them).

I'm not sure where your info came from, but ServerBeach (these days,
anyway) appears to be very reputable.  They're owned by Peer One.  They
also were the original hosting company for YouTube (until Google bought
them).

I did a quick search on "ServerBeach" and "spam" and the top relevant
hit was an article from 2003 when SB shut down a customer in response to
SPEWS complaints, which took down a bunch of innocent sites; it was
reported in the NY Times.

The mailing list software does unsubscribe after a number of bounces,
but it uses an algorithm that requires more than a short outage, so you
should be OK.  But if you receive an unsubscribe notice, you can
resubscribe -- it won't prevent that.

John
----

Bruce Lane said the following on 10/13/2008 02:07 AM:
> 	I just found a bunch of 'Reject' entries in our mail system's log
relating to the time-nuts list. The reason for the rejections is that the
new list server appears to be based with a company called Server Beach.
> 
> 	The reason Server Beach was blocked is because they did, at one
time, have a long and sordid history of supporting spammers. I will grant
that I have not seen a spam attempt from them in some time. Perhaps they
cleaned up their act, finally?
> 
> 	I've punched a hole in the filters for now, specifically to allow
meow.febo.com through, but I'm wondering two things.
> 
> 	(1) Please confirm: Is time-nuts, in fact, now permanently based out
of Server Beach IP space, or is that a temporary assignment?
> 
> 	(2) Will the list drop my subscription because of the rejects? There
were quite a few of them.
> 
> 	Thanks.
> 
> 
> -=-=-=-=-=-=-=-=-=-=-=-
> Bruce Lane, Owner & Head Hardware Heavy,
> Blue Feather Technologies -- http://www.bluefeathertech.com
> kyrrin (at) bluefeathertech do/t c=o=m
> "Quid Malmborg in Plano..."
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 
> 


_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



From javier.serrano.pareja at gmail.com  Mon Oct 13 15:15:24 2008
From: javier.serrano.pareja at gmail.com (Javier Serrano)
Date: Mon, 13 Oct 2008 17:15:24 +0200
Subject: [time-nuts] Phase noise and jitter
Message-ID: <83e48fa10810130815v6a7db6d3he8a0c90fe10e7a0f@mail.gmail.com>

Dear nuts,

I would like to know if there is a clear explanation somewhere with
considerations on how to choose an upper frequency limit when integrating
phase noise to find jitter. Let's say I'm interested in the raw jitter
measurement which comes from integrating phase noise without applying any
filter to it. For a given application, I can easily understand that I can
define a lower integration limit if the time spans I'm interested in are
shorter than some value. For example, we run a synchrotron with a 1.2 second
cycle time. Phase noise in our clocks below say 0.1 Hz should be of no
concern since it is "common mode" to all the triggers we define within any
given cycle using counts of the clock we are characterizing (incidentally I
am also interested in your comments on how a phase noise measurement would
fare against Allan deviation in this frequency area). I have a bit more
trouble with the upper frequency limit. Am I right in saying that the right
answer in principle is to integrate to infinity but due to Physics the phase
noise will at some offset fmax be so low that the contribution of
integrating from fmax to infinity would be negligible? How can I then work
out experimentally which is the value of this fmax? Maybe extrapolating the
slope of the curve I measure using for example a low bandwidth PLL
technique? Thanks for any insight.

Cheers,

Javier

From tvb at LeapSecond.com  Mon Oct 13 15:29:51 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Mon, 13 Oct 2008 08:29:51 -0700
Subject: [time-nuts] Testing frequency using NTP Bruce GPS ps
References: <mailman.195.1222952732.2205.time-nuts@febo.com><E1KlOmJ-0007rp-88@febo.com>
	<48E52F08.8070400@xtra.co.nz><E1KlwtS-0002lT-Ek@febo.com>
	<000f01c925cd$e6c84de0$0300a8c0@pc52><E1KlyXH-0004HB-SC@febo.com>
	<005401c925f2$db402fe0$0300a8c0@pc52><E1KnqaY-0005xh-W5@febo.com>
	<000701c92ce2$8d792e50$0700a8c0@pc52><E1KpEYA-0005hN-W1@meow.febo.com><00e501c92ceb$4a6d17d0$0700a8c0@pc52>
	<E1KpIKa-0007sj-11@meow.febo.com>
Message-ID: <003f01c92d48$90fcc670$0700a8c0@pc52>

Mike,

>  So where did the 1ns granularity come in?

For example, Motorola receivers output the sawtooth correction as
an 8-bit signed binary field in the @@En/Hn TRAIM message. The
range of said byte is -128 to +127; the scale, the granularity, the
units of that field are 1 ns. Make sense now?

>  Thanks, already studied and analyzed. He uses an XOR phase detector,
>  but the  funny hump at 1,000 seconds bothers me. I can't see  a good
>  reason for  that.  The drop starting at 1e4 is  interesting,  and it
>  would have been nice to see what happens further out.

The hump around 1000 seconds is characteristic of quartz-based
GPSDO. It is related to the "cross-over point" where the instability
of the XO meets the stability of GPS on an ADEV plot and to the
time-constant of the PLL.

Here's another GPSDO related link for you to study.
http://www.thinksrs.com/assets/instr/PRS10/PRS10diag2.htm
http://www.thinksrs.com/products/PRS10.htm

/tvb




From jra at febo.com  Mon Oct 13 16:03:06 2008
From: jra at febo.com (John Ackermann N8UR)
Date: Mon, 13 Oct 2008 12:03:06 -0400
Subject: [time-nuts] New servers
In-Reply-To: <A7218DBB413846DCA8C502833E9D940D@joesworkstation>
References: <A7218DBB413846DCA8C502833E9D940D@joesworkstation>
Message-ID: <48F3713A.5070302@febo.com>

febo.com is on a dedicated server that hosts only itself and a few ham
radio websites.  It's under my control, and the IP isn't shared with
anyone else.

John
----

Joseph Grossbauer said the following on 10/13/2008 11:11 AM:
> As a system administrator I'm not a big fan of Server Beach because of their
> letting spammers slide but I did check the IP address of the list on
> mxtoolbox.com and it came up perfectly clean.
> 
> Joe, WA9MSD
> 
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
> Behalf Of John Ackermann N8UR
> Sent: Monday, October 13, 2008 08:30
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] New servers
> 
> Yes, we're now running on a dedicated server at ServerBeach, which is
> also where tapr.org has been hosted for two or three years (and we've
> had very good luck with them).
> 
> I'm not sure where your info came from, but ServerBeach (these days,
> anyway) appears to be very reputable.  They're owned by Peer One.  They
> also were the original hosting company for YouTube (until Google bought
> them).
> 
> I did a quick search on "ServerBeach" and "spam" and the top relevant
> hit was an article from 2003 when SB shut down a customer in response to
> SPEWS complaints, which took down a bunch of innocent sites; it was
> reported in the NY Times.
> 
> The mailing list software does unsubscribe after a number of bounces,
> but it uses an algorithm that requires more than a short outage, so you
> should be OK.  But if you receive an unsubscribe notice, you can
> resubscribe -- it won't prevent that.
> 
> John
> ----
> 
> Bruce Lane said the following on 10/13/2008 02:07 AM:
>> 	I just found a bunch of 'Reject' entries in our mail system's log
> relating to the time-nuts list. The reason for the rejections is that the
> new list server appears to be based with a company called Server Beach.
>> 	The reason Server Beach was blocked is because they did, at one
> time, have a long and sordid history of supporting spammers. I will grant
> that I have not seen a spam attempt from them in some time. Perhaps they
> cleaned up their act, finally?
>> 	I've punched a hole in the filters for now, specifically to allow
> meow.febo.com through, but I'm wondering two things.
>> 	(1) Please confirm: Is time-nuts, in fact, now permanently based out
> of Server Beach IP space, or is that a temporary assignment?
>> 	(2) Will the list drop my subscription because of the rejects? There
> were quite a few of them.
>> 	Thanks.
>>
>>
>> -=-=-=-=-=-=-=-=-=-=-=-
>> Bruce Lane, Owner & Head Hardware Heavy,
>> Blue Feather Technologies -- http://www.bluefeathertech.com
>> kyrrin (at) bluefeathertech do/t c=o=m
>> "Quid Malmborg in Plano..."
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>>
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 
> 



From jmiles at pop.net  Mon Oct 13 19:15:14 2008
From: jmiles at pop.net (John Miles)
Date: Mon, 13 Oct 2008 12:15:14 -0700
Subject: [time-nuts] Phase noise and jitter
In-Reply-To: <83e48fa10810130815v6a7db6d3he8a0c90fe10e7a0f@mail.gmail.com>
Message-ID: <PKEGJHPHLLBACEOICCBJAEJEMLAB.jmiles@pop.net>

Javier Serrano wrote:
> Dear nuts,
>
> I would like to know if there is a clear explanation somewhere with
> considerations on how to choose an upper frequency limit when
> integrating phase noise to find jitter. Let's say I'm interested in
> the raw jitter measurement which comes from integrating phase noise
> without applying any filter to it. For a given application, I can
> easily understand that I can define a lower integration limit if the
> time spans I'm interested in are shorter than some value. For
> example, we run a synchrotron with a
> 1.2 second
> cycle time. Phase noise in our clocks below say 0.1 Hz should be of no
> concern since it is "common mode" to all the triggers we define
> within any given cycle using counts of the clock we are
> characterizing (incidentally I am also interested in your comments on
> how a phase noise measurement would fare against Allan deviation in
> this frequency area). I have a bit more trouble with the upper
> frequency limit. Am I right in saying that
> the right
> answer in principle is to integrate to infinity but due to
> Physics the phase
> noise will at some offset fmax be so low that the contribution of
> integrating from fmax to infinity would be negligible? How can I then
> work out experimentally which is the value of this fmax? Maybe
> extrapolating the
> slope of the curve I measure using for example a low bandwidth PLL
> technique? Thanks for any insight.

Normally the PN reaches a broadband floor determined by the circuit's own
limitations or its semiconductor process.  This happens between 100 kHz and
10 MHz depending on what's generating the signal.  So you wouldn't want to
extrapolate the slope indefinitely.

A high-quality crystal oscillator's broadband floor will be sufficiently
quiet (typically better than -160 dBc/Hz) that it won't matter much whether
you integrate out to 100 kHz or to 1 MHz.  The difference will be on the
order of attoseconds.  When making the measurement, you'd typically place
the upper integration cursor one decade into the broadband-floor region, and
call it good.

There will normally be several regions of the curve beyond the bandwidth of
the PLL used for measurement locking (e.g., page 7 of
http://www.ke5fx.com/Scherer_Art_of_PN_measurement.pdf .  With a crystal
oscillator in particular, the crystal's properties are responsible for the
earlier decades while the circuit's properties normally dominate the later
regions including the broadband floor.  So you'd want to ensure that your
maximum measurement offset is high enough to account for all regions of the
noise profile.  1 MHz to 10 MHz is usually sufficient, and you'll still get
reasonable results in many cases if you stop at 100 kHz.

-- john, KE5FX



From rexa at sonic.net  Mon Oct 13 19:28:11 2008
From: rexa at sonic.net (Rex)
Date: Mon, 13 Oct 2008 12:28:11 -0700
Subject: [time-nuts] Sulzer Labs D-5 oscillator
In-Reply-To: <E1Kootq-0002oD-CQ@febo.com>
References: <rk@timing-consultants.com>	<995765D00C9A462CAED3D7B3FE1865C7@Robin>	<20081011062021.61D43BCD5@ip-64-139-1-69.sjc.megapath.net>	<F17F40AD76BA4994849B95294A8FEA55@Robin>	<E1Koa4m-0006To-CA@febo.com>	<1231b6a80810110218v699ec251ke1cff6779857ad65@mail.gmail.com>	<E1Kob3z-0007Bt-UW@febo.com>	<1231b6a80810111506o7b416205laf934bbae8b646a6@mail.gmail.com>
	<E1Kootq-0002oD-CQ@febo.com>
Message-ID: <48F3A14B.5040700@sonic.net>

Mike Monett wrote:
>   "Steve Rooke" <sar10538 at gmail.com> wrote:
>
>
>   > Well, the obvious one is Thunderbird which will do all  the things
>   > that I  can see that Pimmy can do, given my albeit  brief overview
>   > of this application from the parent website.
>
>   I tried  Thunderbird some time ago, but I think I gave  up  since it
>   would not  handle multiple accounts like Pimmy does.  That  may have
>   changed.
>
>   

I have been using Thunderbird for a couple years, mostly Windows, only 
breifly on Ubuntu. It handles multiple accounts fine. Mine checks 4 
different email accounts. It can also be set to use proper from: address 
when sending. Don't know if there is something else you would want.


From jmiles at pop.net  Mon Oct 13 19:30:14 2008
From: jmiles at pop.net (John Miles)
Date: Mon, 13 Oct 2008 12:30:14 -0700
Subject: [time-nuts] Phase noise and jitter
In-Reply-To: <PKEGJHPHLLBACEOICCBJAEJEMLAB.jmiles@pop.net>
Message-ID: <PKEGJHPHLLBACEOICCBJOEJGMLAB.jmiles@pop.net>


> A high-quality crystal oscillator's broadband floor will be
> sufficiently quiet (typically better than -160 dBc/Hz) that it won't
> matter
> much whether
> you integrate out to 100 kHz or to 1 MHz.  The difference will be on
> the order of attoseconds.

Sorry, should have said "femtoseconds" here.  Going from 10 Hz-100 kHz to 10
Hz-1 MHz with one OCXO plot I have contributes 1E-15 more jitter.  The idea
still applies, though -- just keep moving the upper limit higher until the
difference doesn't matter in your application.  With a high-qualty source
you will not usually need to extrapolate beyond the boundaries of the plot.

-- john, KE5FX



From hasweb at has.org.nz  Mon Oct 13 19:35:55 2008
From: hasweb at has.org.nz (hasweb at has.org.nz)
Date: Tue, 14 Oct 2008 08:35:55 +1300
Subject: [time-nuts] homebrew 13 dBm distribution amplifier based
	on	NIST design 5 to 100 MHz
Message-ID: <20081014083555.5jzs5gssmscowk8c@webmail.has.org.nz>

   Gerhard
     One trick that has been used for fixed frequency isolation amplifiers =20
     is to use a low Q
     series tuned LC circuit to short out the resistor in series with the =20
     base at the
     frequency of interest.
     Using a suitable ferrite bead instead of the resistor may allow a =20
     lower base to ground
     impedance at the signal frequency whilst ensuring transistor stability.
     Such instabilities are perhaps one reason why Spectracom and NIST use =20
     much lower ft
     transistors in their low noise 1-20MHz distribution amplifiers.

     Bruce



From hasweb at has.org.nz  Mon Oct 13 19:38:54 2008
From: hasweb at has.org.nz (hasweb at has.org.nz)
Date: Tue, 14 Oct 2008 08:38:54 +1300
Subject: [time-nuts] Phase noise and jitter
Message-ID: <20081014083854.vw9h40bzpc8ckw8w@webmail.has.org.nz>

Javier Serrano wrote:
> Dear nuts,
>
> I would like to know if there is a clear explanation somewhere with
> considerations on how to choose an upper frequency limit when integrating
> phase noise to find jitter. Let's say I'm interested in the raw jitter
> measurement which comes from integrating phase noise without applying any
> filter to it. For a given application, I can easily understand that I can
> define a lower integration limit if the time spans I'm interested in are
> shorter than some value. For example, we run a synchrotron with a 1.2 second
> cycle time. Phase noise in our clocks below say 0.1 Hz should be of no
> concern since it is "common mode" to all the triggers we define within any
> given cycle using counts of the clock we are characterizing (incidentally I
> am also interested in your comments on how a phase noise measurement would
> fare against Allan deviation in this frequency area). I have a bit more
> trouble with the upper frequency limit. Am I right in saying that the right
> answer in principle is to integrate to infinity but due to Physics the phase
> noise will at some offset fmax be so low that the contribution of
> integrating from fmax to infinity would be negligible? How can I then work
> out experimentally which is the value of this fmax? Maybe extrapolating the
> slope of the curve I measure using for example a low bandwidth PLL
> technique? Thanks for any insight.
>
> Cheers,
>
> Javier
>
Javier

You could do that but the resultant integrated phase noise will be  
quite large and you should take into account the finite bandwidth of  
the signal processing/distribution system.

In practice all amplifiers (buffers, isolation etc), comparators etc  
have a finite bandwidth which rolls of the response to input phase  
noise as well as limiting the devices own contributions to high offset  
phase noise. A typical high quality 10MHz ultra low phase noise  
distribution amplifier may only have a 3db bandpass  of to 1 - 20MHz  
and a corresponding 100MHz distribution amplifier may have a bandpass  
of perhaps 80-120MHz.

Typical high end instruments for measuring Allan deviation may only  
have a bandwidth of a few Hz.

Even logic devices have a finite gain bandwidth in the transition region.

The Allen deviation can be calculated from the phase noise if the  
phase noise is known for all frequencies of interest.

Bruce




From hasweb at has.org.nz  Mon Oct 13 19:40:59 2008
From: hasweb at has.org.nz (hasweb at has.org.nz)
Date: Tue, 14 Oct 2008 08:40:59 +1300
Subject: [time-nuts] [Fwd: Re: What is the best counter for a Time	Nuts?]
Message-ID: <20081014084059.xd9m9xezb4w880s4@webmail.has.org.nz>

Mike Monett wrote:
>   > So, assuming my known timebase is "bang on", I know  the frequency
>   > of the unknown 10 MHz source to an accuracy of roughly 3e-10  or 3
>   > parts in 10 billion.
>
>   > To get  a  more precise measurement  of  the  frequency difference
>   > between the two 10 MHz clocks, I supply the known 10 MHz  clock to
>   > the Channel  A  input  of an HP  3575A  Gain-Phase  meter  and the
>   > unknown 10  MHz  clock to the channel B  input  of  the Gain-Phase
>   > meter.
>
>   Another very  difficult instrument to find any data on.  The  best I
>   could find shows it has an accuracy of ? 0.5 degree and resolution
>   of 0.1 degree.
>
Try the agilent website for the manuals not yet readily available
For directions visit:
www.hparchive.com <http://www.hparchive.com>

There is a 3575A manual for downloading at the Agilent ftp link.
If you read it you will find that the specified error with 10MHz  
inputs is much larger: 10-20 degrees or so.

Bruce




From SAIDJACK at aol.com  Mon Oct 13 20:02:47 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Mon, 13 Oct 2008 16:02:47 EDT
Subject: [time-nuts] Phase noise and jitter
Message-ID: <c0f.3ab85a0b.36250367@aol.com>

Hello John, Javier,
 
you may get bogus numbers when calculating jitter from phase  noise 
measurements with limited bandwidth.
 
For example what about an asyncronous (deterministic jitter) component  
sitting at 103KHz when you only measure with a 100KHz bandwidth? Depending on  the 
level of this 103KHz signal the resulting jitter could look horrible on a  
scope, but would be completely invisible on a 100KHz BW measurement. Such a  
103KHz spur may come from switching power supplies etc, and have a  detrimental 
effect on the signal.
 
For example, I have a Wenzel Ultra low noise OCXO which is extremely low  
noise (around -170dBc/Hz floor) but at the same time it has a large amount of  
noise at around 620MHz or so. I attribute this noise to the digital CMOS  gates 
they seem to use in the buffer stages, followed by low-pass filters that  are 
not attenuating properly at those high frequencies. It can be easily seen on  
a spectrum analyzer for example. 
 
BTW: I asked Wenzel about this, they said "we see this too, it's probably  
caused by mixing artifacts in the spectrum analyzer itself". I don't agree since 
 the noise goes away if I use a 50MHz low pass filter on the signal..
 
Will such higher frequency noise/jitter affect your system? That  depends on 
your systems' requirements.
 
Generally, when measuring jitter it always looks better to measure  with a 
limited bandwidth such as 10MHz or 20MHz as used on PN equipment such as  
E5052B's etc.
 
To give you an example, I have measured the same 10MHz OCXO source  with both 
a limited 10MHz BW and a ~2GHz bandwidth Wavecrest Jitter Analyzer.  The 
result:
 
Jitter as indicated based on PN measurement: ~350fs rms
 
Jitter as indicated by the Wavecrest: ~8ps rms (noisefloor of  <3ps).
 
That's a big difference, and depending on your application could result in  a 
significant increase in your theoretical Bit Error Rate etc.
 
Another item to keep in mind: even if your application has limited  bandwidth 
(say a receiver with only 5MHz IF bandwidth etc) you may get aliasing  back 
into your bandwidth of interest by the mixing of two deterministic noise  
sources etc. So if your source has noise at say 600MHz due to the 60th overtone  of 
your crystal, and your system happens to have some noise at 603MHz, you may  
get a signal down at 3MHz in your IF due to the non linearity of the amps  etc.
 
In my opinion it is always better to verify PN based jitter measurements  
with a wide-bandwidth SA and/or wide-bandwidth jitter analyzer rather than just  
rely on over simplistic PN-to-jitter calculations such as are available online 
 (Wenzel website etc). While they are useful, these may not tell you the 
entire  story.
 
bye,
Said
 
 
In a message dated 10/13/2008 12:26:04 Pacific Daylight Time,  jmiles at pop.net 
writes:

Normally  the PN reaches a broadband floor determined by the circuit's  own
limitations or its semiconductor process.  This happens between  100 kHz and
10 MHz depending on what's generating the signal.  So you  wouldn't want to
extrapolate the slope indefinitely.

A high-quality  crystal oscillator's broadband floor will be sufficiently
quiet (typically  better than -160 dBc/Hz) that it won't matter much whether
you integrate  out to 100 kHz or to 1 MHz.  The difference will be on the
order of  attoseconds.  When making the measurement, you'd typically place
the  upper integration cursor one decade into the broadband-floor region,  and
call it good.




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From phk at phk.freebsd.dk  Mon Oct 13 20:52:42 2008
From: phk at phk.freebsd.dk (Poul-Henning Kamp)
Date: Mon, 13 Oct 2008 20:52:42 +0000
Subject: [time-nuts] DIY Loran-C frequency receiver update (2)
In-Reply-To: Your message of "Sun, 28 Sep 2008 21:46:12 GMT."
	<12050.1222638372@critter.freebsd.dk> 
Message-ID: <28690.1223931162@critter.freebsd.dk>

In message <12050.1222638372 at critter.freebsd.dk>, Poul-Henning Kamp writes:

>Some time ago I send an email about my little project to create a
>LORAN-C frequency receiver for time-nuts purposes, here is an update.

I have gotten quite far with the software now, it can pull in any
signal that can reasonably be expected to be heard at my location.

The software tries to latch onto the strongest loran-station in the
GRI, but due to the approximately equal distance to the stations
it waffles between three different stations in the 9007 chain.

Here are the six signals it can dredge out of my test data:

	http://phk.freebsd.dk/misc/loran_20091013.pdf

The stations are:

	Signal	Location	Relativ vol.	Time to lock
	7499M	Sylt		1.000		16 s
	6731Z	Sylt		0.732		15 s
	9007M	Ei?e		0.043		98 s
	9007X	B?		0.036		69 s
	7001M	B?		0.022		60 s
	9007Y	V?rlandet	0.021		90 s

If the software was told to skip the stong station and take one
of the weaker, more stations could be tracked, just like increasing
the integration time would enable pulling weaker stations out
of the noise.

Neither of this is the point however, the idea is to measure
the frequency of the strongest signal available.


The way the software works is the following:

Phase 1:

Pick out every 100th sample (one per msec) and average these over
the GRI until a pattern of four spikes stand out in either ^v^^
(master) or ^^^v (slave) pattern, at least 2.5 standard deviations
over the set of up to 1000 buckets.

This tells us where the signal we want is, and which code it uses.

The first two plots from the top shows the results of this, with
the red bars indicating the best candidate signal.

Phase 2:

Integrate the first 0..500 and 1000..1500 samples of each gri
and multiply the first set with the second set.  Once the
relative result goes above or below +/- 0.75 we know if we
have the A or B period of the signal.  This is the same for
master and slave codes, since they both have "++..." and "+-..."
in their A and B periods.

The middle plot shows the 1000 buckets and the result of this.

Phase 3:

Integrate the 0..1000 samples summed over the full code.

This is where we will identify the 3rd zerocrossing and track
its position relative to the sample clock.

The fourth plot shows this.

The fifth plot is a debugging aid and shows the full FRI
accumulated along with the fourth plot, at the left is the
A code of the tracked signal, in the middle the B code and
for some of the signals, other members of the chain are visible
along the line.  See for instance page 2 where all the 6731
stations are visible.

Phase 4: is not coded yet, and consists of identifying the
3rd zero crossing and interpolating it's position between
samples.


One intesting detail is that the software does not work for
the 8000 Chayka chain, because averaging over the FRI or GRI
does not filter out broadcasting stations transmitting on
whole multiples of kHz.

The 8000 sample average corresponds to 8 msec of spectrum, so a
signal of 198 kHz would fit exactly 198 * 8 = 1584 periods into
the window and these will integrate just nicely.

Interestingly, this also works for pulling out frequency: integrating
the 8000 bucket multiplied by sin and cos for that frequency gives
a nice phase-vector for the BBC longwave station, or any other
station running on a multiple of 1 kHz.

This should not be a problem for north american chains which
have the XXX0 GRI format, but the averaging algorithm may
not be as effective on these as on the XXXX european GRIs.

Ohh, and the code is 592 lines of C code (exclusive the functions
to read data from my compressed files and to emit postscript plots).

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.


From javier.serrano.pareja at gmail.com  Mon Oct 13 21:04:49 2008
From: javier.serrano.pareja at gmail.com (Javier Serrano)
Date: Mon, 13 Oct 2008 23:04:49 +0200
Subject: [time-nuts] Phase noise and jitter
In-Reply-To: <c0f.3ab85a0b.36250367@aol.com>
References: <c0f.3ab85a0b.36250367@aol.com>
Message-ID: <1223931889.6739.14.camel@serrano-laptop>

Said, what is the operating principle of the Wavecrest Jitter Analyzer?
Is it a sampling scope like the ones Agilent and Tektronix offer? How
does it compare to them? I've googled it but I only found a Chinese site
with little information in English. Another advantage I see for
time-based measurements is that you can go arbitrarily low in offset
from the carrier. In the 5052B you have a PLL with non-zero bandwidth,
so below some offset you probably get an optimistic estimate because the
PLL is actually following the noise. Another item to bear in mind, if my
understanding is right, is that integrating the phase noise plot gives
you the rms jitter between your noisy waveform and the perfect sinewave,
or rather an approximation of it, which is what comes out of the PLL in
say the 5052B. A sampling scope typically measures the time jitter
between two (noisy) rising edges of a clock waveform. In the simplistic
case of white phase noise this should give you a factor sqrt(2) more
jitter than the loose PLL measurement, right? 
Thanks again,
Javier



From SAIDJACK at aol.com  Mon Oct 13 22:07:15 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Mon, 13 Oct 2008 18:07:15 EDT
Subject: [time-nuts] Phase noise and jitter
Message-ID: <caf.35f578d9.36252093@aol.com>

Hello Javier,
 
Wavecrest makes a point of saying they do not operate like a sampling  scope, 
rather like a Time Intervall Analyzer with very high resolution, and up  to 
40.000 measurements/s. See for example page 12 in the manual at this  location:
 
   
_http://www.mhzelectronics.com/ebay/manuals/wavecrest_dts-2079-77-75_digital_time_system_manual.pdf_ 
(http://www.mhzelectronics.com/ebay/manuals/wavecrest_dts-2079-77-75_digital_time_system_manual.pdf) 
 
A sampling scope has all sorts of aliasing issues, and typically much lower  
resolution and noise floor, and is not very good at single-shot events.
 
Their Visi software does have an Oscilloscope view as well btw.
 
The Wavecrest website is gone, maybe they are bankrupt?
 
I have most of their manuals and appnotes in PDF form if you need  them.
 
They do a time intervall measurement using counters running at 100MHz and  
analog interpolators, similar to an HP5334A etc. They took this to another  
dimension though with 800ps resolution at 40000 samples per second and gated  
arming capability etc, up to several GHz bandwidths.
 
The Visi Windows software has special routines for PLL measurement etc.,  and 
this also includes TIA-to-Phase Noise graphing, although I do not find that  
feature very useful.
 
What is extremely useful in your application is the Jitter histogram (you  
can see and quantify immediately if jitter is deterministic, and/or random, and  
what the side lobes values are etc). See the attached example plot, you can 
see  the jitter being split into left, right, random, total, deterministic 
jitter etc  etc. (That happens to be a very low noise OCXO)
 
Since they are concerned about edge-to-edge jitter, it is best to have nice  
fast rising/falling edges on your signal. While Sine Wave signals do work, the 
 unit will give you a lower phase noise floor if you buffer these from Sine 
Waves  to say LVDS signals, or CMOS signals.
 
They are somewhat rare to find, and some distributors try to get $30K or  
more for them, but I have been able to buy several for around $500 on Ebay  in 
the past.
 
bye,
Said
 
 
 
In a message dated 10/13/2008 14:06:09 Pacific Daylight Time,  
javier.serrano.pareja at gmail.com writes:

Said,  what is the operating principle of the Wavecrest Jitter Analyzer?
Is it a  sampling scope like the ones Agilent and Tektronix offer? How
does it  compare to them? I've googled it but I only found a Chinese site
with  little information in English. Another advantage I see for
time-based  measurements is that you can go arbitrarily low in offset
from the carrier.  In the 5052B you have a PLL with non-zero bandwidth,
so below some offset  you probably get an optimistic estimate because the
PLL is actually  following the noise. Another item to bear in mind, if my
understanding is  right, is that integrating the phase noise plot gives
you the rms jitter  between your noisy waveform and the perfect sinewave,
or rather an  approximation of it, which is what comes out of the PLL in
say the 5052B. A  sampling scope typically measures the time jitter
between two (noisy)  rising edges of a clock waveform. In the simplistic
case of white phase  noise this should give you a factor sqrt(2) more
jitter than the loose PLL  measurement, right? 
Thanks  again,
Javier





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From dk4xp at hoffmann-hochfrequenz.de  Mon Oct 13 22:42:54 2008
From: dk4xp at hoffmann-hochfrequenz.de (Gerhard Hoffmann)
Date: Tue, 14 Oct 2008 00:42:54 +0200
Subject: [time-nuts] homebrew 13 dBm distribution amplifier based on
	NIST design 5 to 100 MHz
In-Reply-To: <20081014083555.5jzs5gssmscowk8c@webmail.has.org.nz>
References: <20081014083555.5jzs5gssmscowk8c@webmail.has.org.nz>
Message-ID: <nuf7f4pi2cho7dn4k8vvpua04adgs7j7pg@4ax.com>

On Tue, 14 Oct 2008 08:35:55 +1300, you wrote:

>     One trick that has been used for fixed frequency isolation amplifiers
>     is to use a low Q series tuned LC circuit to short out the resistor 
>     in series with the base at the frequency of interest.

Yes, but when I burn close to 3 Watts / channel and accept two transistor chains
to make it possible to get rid of of the transformers that hurt Tom's application, 
then I won't easily accept new ferrite parts that might spoil that hard won advantage. 
And all the impedance curves for ferrite beads that I have end at 500 MHz or so
and I would need them at 2.5GHz.

>     Using a suitable ferrite bead instead of the resistor may allow a
>     lower base to ground impedance at the signal frequency whilst ensuring 
>     transistor stability.
>     Such instabilities are perhaps one reason why Spectracom and NIST use
>     much lower ft transistors in their low noise 1-20MHz distribution amplifiers.

The BFG31s have the advantage that I have a reel of them in the drawer and the alternatives 
are few. Who else but NXP has a 1W PNP SMD wideband transistor in active production?
OK. At least TO-5?
Killing ft is probably the easiest part, but precise delay comes
naturally with large bandwidth.


regards, Gerhard dk4xp

(who starts thinking about T-coils and ft-doublers :-) 
Would 1 GHz distribution really be a barrier? Probably not.
I have some experience designing 10 GBit/s fiber optic XFP modules and that
should work nicely at 5GHz. )


From hasweb at has.org.nz  Mon Oct 13 23:37:10 2008
From: hasweb at has.org.nz (hasweb at has.org.nz)
Date: Tue, 14 Oct 2008 12:37:10 +1300
Subject: [time-nuts] Fwd: Re: homebrew 13 dBm distribution amplifier
	based	on NIST design 5 to 100 MHz
Message-ID: <20081014123710.xr49jocp4gsg8g0g@webmail.has.org.nz>



----- Forwarded message from hasweb at has.org.nz -----
     Date: Tue, 14 Oct 2008 12:34:56 +1300
     From: hasweb at has.org.nz
Reply-To: hasweb at has.org.nz
  Subject: Re: [time-nuts] homebrew 13 dBm distribution amplifier  
based on NIST design 5 to 100 MHz
       To: Gerhard Hoffmann <dk4xp at hoffmann-hochfrequenz.de>

Quoting Gerhard Hoffmann <dk4xp at hoffmann-hochfrequenz.de>:

> On Tue, 14 Oct 2008 08:35:55 +1300, you wrote:
>
>>     One trick that has been used for fixed frequency isolation amplifiers
>>     is to use a low Q series tuned LC circuit to short out the resistor
>>     in series with the base at the frequency of interest.
>
> Yes, but when I burn close to 3 Watts / channel and accept two    
> transistor chains
> to make it possible to get rid of of the transformers that hurt    
> Tom's application,
> then I won't easily accept new ferrite parts that might spoil that    
> hard won advantage.
> And all the impedance curves for ferrite beads that I have end at    
> 500 MHz or so
> and I would need them at 2.5GHz.
>
>>     Using a suitable ferrite bead instead of the resistor may allow a
>>     lower base to ground impedance at the signal frequency whilst ensuring
>>     transistor stability.
>>     Such instabilities are perhaps one reason why Spectracom and NIST use
>>     much lower ft transistors in their low noise 1-20MHz    
>> distribution amplifiers.
>
> The BFG31s have the advantage that I have a reel of them in the    
> drawer and the alternatives
> are few. Who else but NXP has a 1W PNP SMD wideband transistor in    
> active production?
> OK. At least TO-5?
> Killing ft is probably the easiest part, but precise delay comes
> naturally with large bandwidth.
>
>
> regards, Gerhard dk4xp
>
> (who starts thinking about T-coils and ft-doublers :-)
> Would 1 GHz distribution really be a barrier? Probably not.
> I have some experience designing 10 GBit/s fiber optic XFP modules and that
> should work nicely at 5GHz. )
>
>

Gerhard

You don't have to use ferrite cored inductors for the series resonant
base bypass networks.

I can remember forming Tcoil terminations by forming an inductor from
the lead wire of the axial leaded termination resistor and adjusting
the turns spacing whilst using a classical sampling scope to observe
the reflections from the input.

In practice one often needs to limit the bandwidth of a frequency
distribution system to keep the integrated phase noise at a reasonable
level.

A 1GHz bandwidth distribution amplifier is really only necessary when
one has to distribute a 1GHz signal.

Even with more modest bandwidth distribution amplifiers using lower ft
transistors, the phase shift tempco of a typical double balanced mixer
at 5 or 10MHz can be much larger than that of the distribution
amplifier and can dominate the phase shift tempco of a system.

Bruce


----- End forwarded message -----




From K6YAZ at aol.com  Tue Oct 14 00:59:50 2008
From: K6YAZ at aol.com (K6YAZ at aol.com)
Date: Mon, 13 Oct 2008 20:59:50 EDT
Subject: [time-nuts] Connectors for the Datum LPRO Rubidium Oscillator
Message-ID: <c04.4a9e1674.36254906@aol.com>

I have ten-pin female connectors for the LPRO Rubidium Oscillators. The  cost 
for two connectors, postage paid in the US is $2.50. 
 
If you use these connectors, don't use too much heat and use small  wires; 
there are a lot of pins in a small area.
 
I will accepts checks and PayPal (_stuartl73 at aol.com_ 
(mailto:stuartl73 at aol.com) ). 
 
 
 
Stuart Landau
23452 Justice St.
West Hills, CA 91304
 
 
Thanks for looking,
 
Stuart K6YAZ
 
**************New MapQuest Local shows what's happening at your destination.  
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From XDE-L2G3 at myamail.com  Tue Oct 14 03:09:03 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Mon, 13 Oct 2008 23:09:03 -0400
Subject: [time-nuts]
	=?iso-8859-1?q?=5BFwd=3A_Re=3A_What_is_the_best_count?=
	=?iso-8859-1?q?er_for_a_Time=09Nuts=3F=5D?=
References: <20081014084059.xd9m9xezb4w880s4@webmail.has.org.nz>
Message-ID: <mailman.0.1223953752.2504.time-nuts@febo.com>

hasweb at has.org.nz wrote:
>
>Mike Monett wrote:
>>   > So, assuming my known timebase is "bang on", I know  the frequency
>>   > of the unknown 10 MHz source to an accuracy of roughly 3e-10  or 3
>>   > parts in 10 billion.
>>
>>   > To get  a  more precise measurement  of  the  frequency difference
>>   > between the two 10 MHz clocks, I supply the known 10 MHz  clock to
>>   > the Channel  A  input  of an HP  3575A  Gain-Phase  meter  and the
>>   > unknown 10  MHz  clock to the channel B  input  of  the Gain-Phase
>>   > meter.
>>
>>   Another very  difficult instrument to find any data on.  The  best I
>>   could find shows it has an accuracy of ? 0.5 degree and resolution
>>   of 0.1 degree.
>>
>Try the agilent website for the manuals not yet readily available
>For directions visit:
>www.hparchive.com <http://www.hparchive.com>
>
>There is a 3575A manual for downloading at the Agilent ftp link.
>If you read it you will find that the specified error with 10MHz  
>inputs is much larger: 10-20 degrees or so.
>
>Bruce

There is nothing in the hparchive site, and I don't have the Agilent ftp
site url.

Could you give a direct link to the 3575A manual?

The basic principle is sound. It should be very easy to make a simple PWM
circuit to measure phase accurately at 10MHz. You mentioned the same thing
earlier. Why not post the schematic so we can take a look?

Mike Monett


From XDE-L2G3 at myamail.com  Tue Oct 14 03:54:44 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Mon, 13 Oct 2008 23:54:44 -0400
Subject: [time-nuts] Testing frequency using NTP Bruce GPS ps
References: <mailman.195.1222952732.2205.time-nuts@febo.com>
	<E1KlOmJ-0007rp-88@febo.com> <48E52F08.8070400@xtra.co.nz>
	<E1KlwtS-0002lT-Ek@febo.com> <000f01c925cd$e6c84de0$0300a8c0@pc52>
	<E1KlyXH-0004HB-SC@febo.com> <005401c925f2$db402fe0$0300a8c0@pc52>
	<E1KnqaY-0005xh-W5@febo.com> <000701c92ce2$8d792e50$0700a8c0@pc52>
	<E1KpEYA-0005hN-W1@meow.febo.com>
	<00e501c92ceb$4a6d17d0$0700a8c0@pc52>
	<E1KpIKa-0007sj-11@meow.febo.com>
	<003f01c92d48$90fcc670$0700a8c0@pc52>
Message-ID: <mailman.1.1223956494.2504.time-nuts@febo.com>


  >Mike,

  >> So where did the 1ns granularity come in?

  > For example, Motorola receivers output the sawtooth  correction as
  > an 8-bit  signed  binary field in the @@En/Hn  TRAIM  message. The
  > range of  said byte is -128 to +127; the  scale,  the granularity,
  > the units of that field are 1 ns. Make sense now?

  Thanks, but I still can't make the connection. I have  studied every
  site I can find on GPS architecture. Some are very good, but I can't
  find anything that relates a 1 second GPS message to the 1PPS pulse.

  I can  understand how the sawtooth is generated from a  crystal that
  doesn't have a convenient division factor to get to 1 Hz.  I believe
  similar pulse-swallowing  techniques  are  used  in  synthesizers to
  generate arbitrary  division ratios. Unfortunately  these  have poor
  phase noise.

  In any  event,  my system ignores all  the  timing  and quantization
  errors in the 1PPS signal. What I am really interested in is how the
  GPS receiver  can  identify  the  correct  time  messages  from many
  different satellites  at wildly different distances,  with  huge and
  changing doppler  shift, and old satellites  constantly  leaving and
  new ones appearing. That is a complete mystery.

  >> Thanks, already  studied  and  analyzed.  He  uses  an  XOR phase
  >> detector, but the funny hump at 1,000 seconds bothers me. I can't
  >> see a  good  reason  for  that.   The  drop  starting  at  1e4 is
  >> interesting, and  it  would have been nice  to  see  what happens
  >> further out.

  > The hump  around  1000 seconds is  characteristic  of quartz-based
  > GPSDO. It  is  related   to   the   "cross-over  point"  where the
  > instability of  the XO meets the stability of GPS on an  ADEV plot
  > and to the time-constant of the PLL.

  OK, thanks. That seems similar to the phase noise shelf in PLL loops.

  But why can't the GPS correct the oscillator faster? Why is the loop
  time constant so long?

  I think  that  has to do with the errors in the  1PPS  output pulse,
  such as sawtooth, quantization, and so on.

  And that what I hope my system will fix.

  > Here's another GPSDO related link for you to study.

  >http://www.thinksrs.com/assets/instr/PRS10/PRS10diag2.htm
  >http://www.thinksrs.com/products/PRS10.htm

  Yes. Drool, drool:)

  Did you know your page at

  http://www.leapsecond.com/museum/lpro/

  is referenced by Bob at "Rubidium and GPS DO From China" on eBay?

  To see it, go to eBay and search

  RUBIDIUM DATUM LPRO 10Mhz Oscillator longer Lamp life

  The graph at the bottom of the page is what convinced me to  get the
  LPRO instead  of  the cheaper rubidium version on  eBay.  Your graph
  shows the  LPRO is just as good as the PRS10 for averaging  times of
  one second or longer. That is fantastic! Thanks very much.

  BTW, were  you going to send me the log20696.txt file shown  on your
  web page? Or maybe link to it so others can se it also?

  >/tvb

  Thanks for all your help.

  Best Regards

  Mike Monett


From hasweb at has.org.nz  Tue Oct 14 03:58:45 2008
From: hasweb at has.org.nz (hasweb at has.org.nz)
Date: Tue, 14 Oct 2008 16:58:45 +1300
Subject: [time-nuts] [Fwd: Re: What is the best counter for a Time	Nuts?]
In-Reply-To: <E1KpaHY-0003Vj-Uw@meow.febo.com>
References: <20081014084059.xd9m9xezb4w880s4@webmail.has.org.nz>
	<E1KpaHY-0003Vj-Uw@meow.febo.com>
Message-ID: <20081014165845.rtpvg7c28cwwk4oc@webmail.has.org.nz>

Quoting Mike Monett <XDE-L2G3 at myamail.com>:

> hasweb at has.org.nz wrote:
>>
>> Mike Monett wrote:
>>>   > So, assuming my known timebase is "bang on", I know  the frequency
>>>   > of the unknown 10 MHz source to an accuracy of roughly 3e-10  or 3
>>>   > parts in 10 billion.
>>>
>>>   > To get  a  more precise measurement  of  the  frequency difference
>>>   > between the two 10 MHz clocks, I supply the known 10 MHz  clock to
>>>   > the Channel  A  input  of an HP  3575A  Gain-Phase  meter  and the
>>>   > unknown 10  MHz  clock to the channel B  input  of  the Gain-Phase
>>>   > meter.
>>>
>>>   Another very  difficult instrument to find any data on.  The  best I
>>>   could find shows it has an accuracy of ? 0.5 degree and resolution
>>>   of 0.1 degree.
>>>
>> Try the agilent website for the manuals not yet readily available
>> For directions visit:
>> www.hparchive.com <http://www.hparchive.com>
>>
>> There is a 3575A manual for downloading at the Agilent ftp link.
>> If you read it you will find that the specified error with 10MHz
>> inputs is much larger: 10-20 degrees or so.
>>
>> Bruce
>
> There is nothing in the hparchive site, and I don't have the Agilent ftp
> site url.
>
> Could you give a direct link to the 3575A manual?
>
> The basic principle is sound. It should be very easy to make a simple PWM
> circuit to measure phase accurately at 10MHz. You mentioned the same thing
> earlier. Why not post the schematic so we can take a look?
>
> Mike Monett
>
> _______________________________________________
>

Mike

I did some time ago, for some examples (other implementations are also  
possible ) see:

http://www.ko4bb.com/~bruce/LinearPhaseComparators.html

HP used to make the K345991A phase comparator for this purpose.
They also produced other variants for use with their caesium beam standards.


The quickest and easiest is to use the AD9901 phase detector as it  
only has a few ns of non linearity at the end of the range. For higher  
resolution just add a sigma delta ADC.


The Agilent link link:

ftp://ftp.agilent.com/pub/manuals/

is actually at the bottom of the text at the top of the equipment page  
on the hparchive site

Sorry I cant post the site as a link as I am temporarily using a  
backup email server as the regular one can't yet find the new time  
nuts server.


Bruce



From james.p.lux at jpl.nasa.gov  Tue Oct 14 04:11:56 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Mon, 13 Oct 2008 21:11:56 -0700
Subject: [time-nuts] Testing frequency using NTP Bruce GPS ps
In-Reply-To: <E1Kpazm-0003yW-NT@meow.febo.com>
Message-ID: <C5196A1C.1AFE%James.P.Lux@jpl.nasa.gov>




On 10/13/08 8:54 PM, "Mike Monett" <XDE-L2G3 at myamail.com> wrote:

>
>
>> Mike,
>
>>> So where did the 1ns granularity come in?
>
>> For example, Motorola receivers output the sawtooth  correction as
>> an 8-bit  signed  binary field in the @@En/Hn  TRAIM  message. The
>> range of  said byte is -128 to +127; the  scale,  the granularity,
>> the units of that field are 1 ns. Make sense now?
>
>   Thanks, but I still can't make the connection. I have  studied every
>   site I can find on GPS architecture. Some are very good, but I can't
>   find anything that relates a 1 second GPS message to the 1PPS pulse.

The Nav message is transmitted from the satellite, synchronized to the 1
second epoch.

>
>   I can  understand how the sawtooth is generated from a  crystal that
>   doesn't have a convenient division factor to get to 1 Hz.  I believe
>   similar pulse-swallowing  techniques  are  used  in  synthesizers to
>   generate arbitrary  division ratios. Unfortunately  these  have poor
>   phase noise.
>
>   In any  event,  my system ignores all  the  timing  and quantization
>   errors in the 1PPS signal. What I am really interested in is how the
>   GPS receiver  can  identify  the  correct  time  messages  from many
>   different satellites  at wildly different distances,  with  huge and
>   changing doppler  shift, and old satellites  constantly  leaving and
>   new ones appearing. That is a complete mystery.

Actually, that's the easy part. Given that you know your position and
velocity (state vector) and the position and velocity of the satellites
(that's in the ephemeris message), you can calculate the range and range
rate (doppler) for each satellite (visible or not).

The  receiver actually measures apparent range (PN code phase) and range
rate for each of the signals its tracking.  That range and range rate is
offset by the local clock error (and clock error rate).

The nav solution is done by setting up a set of simultaneous equations to
solve for the position and local clock offset and clock offset rate.

In reality, most receivers actually do an iterative solution where an
estimate of the receiver's state vector (position, velocity, and clock error
(frequency and rate of frequency)) is updated using a Kalman filter.  The
filter can also use the carrier frequency offset (since the PN code is
coherent with the carrier).

Knowing an approximate position makes it easier to acquire the PN code in
the first place by reducing the search space before you get lock, because
you can calculate approximately what the phase should be.


>
>> The hump  around  1000 seconds is  characteristic  of quartz-based
>> GPSDO. It  is  related   to   the   "cross-over  point"  where the
>> instability of  the XO meets the stability of GPS on an  ADEV plot
>> and to the time-constant of the PLL.
>
>   OK, thanks. That seems similar to the phase noise shelf in PLL loops.

Yes.

>
>   But why can't the GPS correct the oscillator faster? Why is the loop
>   time constant so long?

Because the GPS solution has short term variability from a variety of
sources: multipath and movement of the phase center with respect to look
angle are both on the order of several millimeters, if not centimeters.  As
the satellite moves across the sky, the fact that your GPS receive antenna
isn't a perfect point source and that the spacecraft antenna isn't either
changes the apparent length of the path.  There are also short term
ionospheric propagation effects.  In fact, there's a whole raft of factors
all in that tens of millimeters area that add up.  SO what you have is a
nice stable Cs clock in orbit, with a path from that clock to you that
screws up the Allan deviation for short tau.


>



From Arnold.Tibus at gmx.de  Tue Oct 14 09:25:34 2008
From: Arnold.Tibus at gmx.de (Arnold Tibus)
Date: Tue, 14 Oct 2008 11:25:34 +0200
Subject: [time-nuts] connection check, to be deleted
Message-ID: <mailman.2.1223976452.2504.time-nuts@febo.com>

Hello,
this is just to check if the link is working again,
thank you.

73
Arnold




From mfeher at eozinc.com  Tue Oct 14 18:12:05 2008
From: mfeher at eozinc.com (Mike Feher)
Date: Tue, 14 Oct 2008 14:12:05 -0400
Subject: [time-nuts] GPS Constellation
In-Reply-To: <20081014165845.rtpvg7c28cwwk4oc@webmail.has.org.nz>
References: <20081014084059.xd9m9xezb4w880s4@webmail.has.org.nz><E1KpaHY-0003Vj-Uw@meow.febo.com>
	<20081014165845.rtpvg7c28cwwk4oc@webmail.has.org.nz>
Message-ID: <C33D6948D9E84004AA41F469414D307A@gsmacdq14es>

Well, no one jumped in to answer my question regarding frequency accuracy
that I asked on here a week or so ago. Maybe I'll get some answers to this
simpler question. Does anyone know of a web site that shows the GPS
satellites in view, at a set of given coordinates on the earth, at any given
time? A graphical presentation would be ideal. Thanks - Mike

 
 
Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960
 
 



From james.p.lux at jpl.nasa.gov  Tue Oct 14 18:28:10 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Tue, 14 Oct 2008 11:28:10 -0700
Subject: [time-nuts] GPS Constellation
In-Reply-To: <C33D6948D9E84004AA41F469414D307A@gsmacdq14es>
Message-ID: <C51A32CA.1B56%James.P.Lux@jpl.nasa.gov>

http://www.heavens-above.com/



On 10/14/08 11:12 AM, "Mike Feher" <mfeher at eozinc.com> wrote:

Well, no one jumped in to answer my question regarding frequency accuracy
that I asked on here a week or so ago. Maybe I'll get some answers to this
simpler question. Does anyone know of a web site that shows the GPS
satellites in view, at a set of given coordinates on the earth, at any given
time? A graphical presentation would be ideal. Thanks - Mike



Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960




_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.


From chris.kuethe at gmail.com  Tue Oct 14 18:39:15 2008
From: chris.kuethe at gmail.com (Chris Kuethe)
Date: Tue, 14 Oct 2008 11:39:15 -0700
Subject: [time-nuts] GPS Constellation
In-Reply-To: <C33D6948D9E84004AA41F469414D307A@gsmacdq14es>
References: <20081014084059.xd9m9xezb4w880s4@webmail.has.org.nz>
	<E1KpaHY-0003Vj-Uw@meow.febo.com>
	<20081014165845.rtpvg7c28cwwk4oc@webmail.has.org.nz>
	<C33D6948D9E84004AA41F469414D307A@gsmacdq14es>
Message-ID: <91981b3e0810141139j2adb9927r76719b65d28fb5e@mail.gmail.com>

two things i can think of:
1) grab a copy of the trimble planning tools. they're not a web page,
but they can compute a constellation (and your view of it) at an
arbitrary place and time.
2) grab a copy of GPSTk. This can also do the calculations, but GUI
display is up to you.

On Tue, Oct 14, 2008 at 11:12 AM, Mike Feher <mfeher at eozinc.com> wrote:
> Well, no one jumped in to answer my question regarding frequency accuracy
> that I asked on here a week or so ago. Maybe I'll get some answers to this
> simpler question. Does anyone know of a web site that shows the GPS
> satellites in view, at a set of given coordinates on the earth, at any given
> time? A graphical presentation would be ideal. Thanks - Mike
>
>
>
> Mike B. Feher, N4FS
> 89 Arnold Blvd.
> Howell, NJ, 07731
> 732-886-5960
>
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>



-- 
GDB has a 'break' feature; why doesn't it have 'fix' too?


From james.p.lux at jpl.nasa.gov  Tue Oct 14 18:50:32 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Tue, 14 Oct 2008 11:50:32 -0700
Subject: [time-nuts] GPS Constellation
In-Reply-To: <91981b3e0810141139j2adb9927r76719b65d28fb5e@mail.gmail.com>
Message-ID: <C51A3808.1B5E%James.P.Lux@jpl.nasa.gov>

http://en.wikipedia.org/wiki/Wikipedia:Featured_picture_candidates/Animated_representation_of_the_orbit_of_the_GPS_system

Might give you some ways to start.

There's a raft of GPS surveying planning applications out there that are designed to tell you which s/v are where at what time. It was a big deal back when the constellation wasn't fully filled and you wanted to do precise surveying.  There's also time keeping applications where you're doing common-view time transfer, so there's some applications that will tell you when and which satellites are in view for both ground stations at the same time.

Jim


On 10/14/08 11:39 AM, "Chris Kuethe" <chris.kuethe at gmail.com> wrote:

two things i can think of:
1) grab a copy of the trimble planning tools. they're not a web page,
but they can compute a constellation (and your view of it) at an
arbitrary place and time.
2) grab a copy of GPSTk. This can also do the calculations, but GUI
display is up to you.

On Tue, Oct 14, 2008 at 11:12 AM, Mike Feher <mfeher at eozinc.com> wrote:
> Well, no one jumped in to answer my question regarding frequency accuracy
> that I asked on here a week or so ago. Maybe I'll get some answers to this
> simpler question. Does anyone know of a web site that shows the GPS
> satellites in view, at a set of given coordinates on the earth, at any given
> time? A graphical presentation would be ideal. Thanks - Mike
>
>
>
> Mike B. Feher, N4FS
> 89 Arnold Blvd.
> Howell, NJ, 07731
> 732-886-5960
>
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>



--
GDB has a 'break' feature; why doesn't it have 'fix' too?

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.


From tvb at LeapSecond.com  Tue Oct 14 19:21:37 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Tue, 14 Oct 2008 12:21:37 -0700
Subject: [time-nuts] GPS Constellation
References: <20081014084059.xd9m9xezb4w880s4@webmail.has.org.nz><E1KpaHY-0003Vj-Uw@meow.febo.com><20081014165845.rtpvg7c28cwwk4oc@webmail.has.org.nz>
	<C33D6948D9E84004AA41F469414D307A@gsmacdq14es>
Message-ID: <004401c92e32$18047e80$0500a8c0@pc52>

> Well, no one jumped in to answer my question regarding frequency accuracy
> that I asked on here a week or so ago. Maybe I'll get some answers to this
> simpler question. Does anyone know of a web site that shows the GPS
> satellites in view, at a set of given coordinates on the earth, at any given
> time? A graphical presentation would be ideal. Thanks - Mike

Mike,

I needed something similar a while ago and ended up with
some animations too:
http://www.leapsecond.com/pages/prn32/

My favorite visual satellite tool is:
http://science.nasa.gov/Realtime/jtrack/3d/JTrack3d.html

/tvb



From tvb at LeapSecond.com  Tue Oct 14 19:38:19 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Tue, 14 Oct 2008 12:38:19 -0700
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
References: <33928620-888F-48A0-9F52-6427F5F0BEED@gmail.com><5A4EFAE4A47A4D428BED3350ECF22BED@didierhp><768835EB-4675-4E19-8971-7C2C9098ADA6@gmail.com><03A6F2CF0F504F9DA5B0D8F919CEBDDB@didierhp>
	<2D3C7CD387614F5F8D3521363034E0F0@gsmacdq14es>
Message-ID: <005401c92e34$71099400$0500a8c0@pc52>

Mike,

I keep hoping to find a Mini-T on eBay but no luck yet and so I
don't have plots on my web site for that unit. Does anyone have
a loaner?

Question on the spec and on your plot, though. What is the gate
time of the frequency measurements? If you average for an hour
or a day many of those peaks would melt.

Also most look like phase jumps not frequency jumps. When you
see frequency jump up and then down by the same amount as a
pair it's usually the result of a single phase jump.

Did you log sats-in-view, or DOP, or temp during your run to see
if the jumps correlated to that?

Finally, "frequency drift" is not at all the same thing as "frequency
excursions", so what did they really mean?

/tvb

> The attached URL is a 11 day plot of a 30.5 GHz carrier taken every minute
> by an Agilent 53152A microwave counter. The Mini-T has an ovenized
> oscillator. It appears that the GPS attempts to over correct the oscillator,
> hence the large frequency excursions. The real large excursions, around the
> 96 hour range, were due to a loose connector. The requirements are such that
> over a 90 day period the total frequency drift shall be no more than 1 KHz.
> Someone in their ultimate wisdom, decided that since they do not have the
> time to take measurements for 90 days, they will take it for 24 hours and
> not allow any frequency excursions over 11 Hz at 30.5 GHz. Obviously, this
> plot does not pass their requirement. When the oscillator is allowed to free
> run, the frequency jumps are not there. Has any one else made any
> measurements on the Trimble Mini-T. Any observations or suggestions are
> appreciated. Regards - Mike
> 
> http://www.eozinc.com/11dayplot.pdf
> 
> 
> Mike B. Feher, N4FS
> 89 Arnold Blvd.
> Howell, NJ, 07731
> 732-886-5960




From namichie at gmail.com  Tue Oct 14 22:38:26 2008
From: namichie at gmail.com (Neville Michie)
Date: Wed, 15 Oct 2008 09:38:26 +1100
Subject: [time-nuts] How many seconds in a year?
Message-ID: <D79C2293-D35E-4D87-8ED7-89A12D01C459@gmail.com>

Hi,
the GPS system obviously counts seconds, and weeks.  When the solar  
year develops a  phase
difference of more than half a second the UTC crowd  consider a leap  
second, so what is the current
rotational velocity of the Earth, either WRT the Sun or the stars? In  
seconds.
I could find many answers on Google but none that seemed good enough  
to set your clock by.
By clock I just mean a rubidium clock that is harmonised to the GPS  
system.
cheers, Neville Michie


From mfeher at eozinc.com  Tue Oct 14 22:45:35 2008
From: mfeher at eozinc.com (Mike Feher)
Date: Tue, 14 Oct 2008 18:45:35 -0400
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
In-Reply-To: <005401c92e34$71099400$0500a8c0@pc52>
References: <33928620-888F-48A0-9F52-6427F5F0BEED@gmail.com><5A4EFAE4A47A4D428BED3350ECF22BED@didierhp><768835EB-4675-4E19-8971-7C2C9098ADA6@gmail.com><03A6F2CF0F504F9DA5B0D8F919CEBDDB@didierhp><2D3C7CD387614F5F8D3521363034E0F0@gsmacdq14es>
	<005401c92e34$71099400$0500a8c0@pc52>
Message-ID: <3D8AF072BD0E488F841494B79C5CA7F0@gsmacdq14es>

Tom -

 

Thanks for your reply. I was not present during the testing. In my opinion,
and now I have been able to convince others, the contractor passed the test,
which is derived from MIL-STD-118-164ACN2. The main specification states the
following:

 

5.1.2.5 Carrier frequency accuracy. The carrier frequency accuracy at the
antenna feed shall be within 1 KHz of the intended value for all RF
carriers. Recalibration intervals to maintain this accuracy shall not be
less than 90 days. 

 

This is on an Army satellite terminal. Another branch of the Army came up
with the 11 Hz requirement over 24 hours (for testing purposes), which is
just 1KHz/90, and I feel it is total rubbish.  I myself have been trying to
find out the gate time used on the counter, but have not been abler to get
it yet and not sure I will. Needles to say, using the stated counter, and
logging a measurement at one minute intervals with a resulting readout down
to 1 Hz at 30 GHz, probably does not leave too many options for gate time.
The jumps do not exactly come in pairs, although they seem to, but, remember
there are close to 16,000 points on that graph. I agree with you that
averaging would make the plot into a straight line. 

 

During the testing this terminal was in California, outside, so the
temperature extremes were just the day to night extremes and relatively slow
respect to time. I doubt if they knew the sats-in-view, but I will ask, and
I am certain that they have no idea about DOP, and I am not sure how that
would affect the frequency measured. I pointed out about 6 months ago that I
did not like where they had their GPS antenna mounted as it was, at times,
blocked by the 2.4 meter reflector. They do believe that at times they lost
some birds and since re-located the GPS antenna. 

 

I did contact John Vig about this, however at this time he is too busy with
his activities as President elect of the IEEE, a post which he will take in
2009. He also retired from the Army in 2006. He did give me another contact
within the Army, Ray Filler, and Ray is in agreement with all of my
assumptions and conclusions, and is in the process of reading a white paper
on the subject that I wrote. I was just hoping to get some ideas from this
august group, hence the reason for my post. I will let you know if I find
out anything else. BTW, loopback testing on the terminal at threshold Eb/No
yielded the desired BER without any synch losses over a 24 hour period.
Thanks & Regards - Mike 

 

 

Mike B. Feher, N4FS

89 Arnold Blvd.

Howell, NJ, 07731

732-886-5960

 

 

 

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Tom Van Baak
Sent: Tuesday, October 14, 2008 3:38 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Frequency Stability of Trimble Mini-T

 

Mike,

 

I keep hoping to find a Mini-T on eBay but no luck yet and so I

don't have plots on my web site for that unit. Does anyone have

a loaner?

 

Question on the spec and on your plot, though. What is the gate

time of the frequency measurements? If you average for an hour

or a day many of those peaks would melt.

 

Also most look like phase jumps not frequency jumps. When you

see frequency jump up and then down by the same amount as a

pair it's usually the result of a single phase jump.

 

Did you log sats-in-view, or DOP, or temp during your run to see

if the jumps correlated to that?

 

Finally, "frequency drift" is not at all the same thing as "frequency

excursions", so what did they really mean?

 

/tvb

 

> The attached URL is a 11 day plot of a 30.5 GHz carrier taken every minute

> by an Agilent 53152A microwave counter. The Mini-T has an ovenized

> oscillator. It appears that the GPS attempts to over correct the
oscillator,

> hence the large frequency excursions. The real large excursions, around
the

> 96 hour range, were due to a loose connector. The requirements are such
that

> over a 90 day period the total frequency drift shall be no more than 1
KHz.

> Someone in their ultimate wisdom, decided that since they do not have the

> time to take measurements for 90 days, they will take it for 24 hours and

> not allow any frequency excursions over 11 Hz at 30.5 GHz. Obviously, this

> plot does not pass their requirement. When the oscillator is allowed to
free

> run, the frequency jumps are not there. Has any one else made any

> measurements on the Trimble Mini-T. Any observations or suggestions are

> appreciated. Regards - Mike

> 

> http://www.eozinc.com/11dayplot.pdf

> 

> 

> Mike B. Feher, N4FS

> 89 Arnold Blvd.

> Howell, NJ, 07731

> 732-886-5960

 

 

 

_______________________________________________

time-nuts mailing list -- time-nuts at febo.com

To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

and follow the instructions there.


From hasweb at has.org.nz  Tue Oct 14 22:58:13 2008
From: hasweb at has.org.nz (hasweb at has.org.nz)
Date: Wed, 15 Oct 2008 11:58:13 +1300
Subject: [time-nuts] How many seconds in a year?
Message-ID: <20081015115813.w0pg84g8e88swgss@webmail.has.org.nz>

Neville Michie wrote:
> Hi,
> the GPS system obviously counts seconds, and weeks.  When the solar   
> year develops a  phase
> difference of more than half a second the UTC crowd  consider a leap  
>  second, so what is the current
> rotational velocity of the Earth, either WRT the Sun or the stars?  
> In  seconds.
> I could find many answers on Google but none that seemed good enough  
>  to set your clock by.
> By clock I just mean a rubidium clock that is harmonised to the GPS  system.
> cheers, Neville Michie
>
Neville

Leapseconds are due to the fact that the Earths rotation period about  
its axis wrt the mean sun is not exactly 86400 seconds.
The rate isnt spot on and the rotation period evolves with time due to  
earthquakes and other causes.

The length of the year is another matter entirely.

Bruce



From tvb at LeapSecond.com  Tue Oct 14 23:11:01 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Tue, 14 Oct 2008 16:11:01 -0700
Subject: [time-nuts] How many seconds in a year?
References: <D79C2293-D35E-4D87-8ED7-89A12D01C459@gmail.com>
Message-ID: <000901c92e52$24fa9e10$0500a8c0@pc52>

> Hi,
> the GPS system obviously counts seconds, and weeks.  When the solar  
> year develops a  phase
> difference of more than half a second the UTC crowd  consider a leap  
> second, so what is the current
> rotational velocity of the Earth, either WRT the Sun or the stars? In  
> seconds.
> I could find many answers on Google but none that seemed good enough  
> to set your clock by.
> By clock I just mean a rubidium clock that is harmonised to the GPS  
> system.
> cheers, Neville Michie

One leap second every few years is equivalent to about 1e-8.
So the answer to your question only starts to matter when
measurements are more precise than 8 digits. See also:

<Earth: An Oscillator and Frequency Standard>
http://www.leapsecond.com/museum/earth/

/tvb



From dforbes at dakotacom.net  Wed Oct 15 00:50:46 2008
From: dforbes at dakotacom.net (David Forbes)
Date: Tue, 14 Oct 2008 17:50:46 -0700
Subject: [time-nuts] How many seconds in a year?
In-Reply-To: <D79C2293-D35E-4D87-8ED7-89A12D01C459@gmail.com>
References: <D79C2293-D35E-4D87-8ED7-89A12D01C459@gmail.com>
Message-ID: <a06240500c51aecf2bb80@[192.168.0.24]>

At 9:38 AM +1100 10/15/08, Neville Michie wrote:
>Hi,
>the GPS system obviously counts seconds, and weeks.  When the solar
>year develops a  phase
>difference of more than half a second the UTC crowd  consider a leap
>second, so what is the current
>rotational velocity of the Earth, either WRT the Sun or the stars? In
>seconds.
>I could find many answers on Google but none that seemed good enough
>to set your clock by.
>By clock I just mean a rubidium clock that is harmonised to the GPS
>system.
>cheers, Neville Michie

Neville,

Unfortunately, the Earth's rotation and revolution around are not as 
stable as the oscillations of your rubidium clock.

There is no formula for leap seconds; the folks who insert or 
subtract the leap seconds do so using observations of the stars as a 
guide. You could say that leap seconds represent the noisy 
least-significant digit in the Earth's somewhat jerky movement. 
(Jerky relative to the smoothness of a rubidium clock, that is.)

It would be convenient for clockmakers if they calculated the best 
fit to a long-term trend of the Earth's behavior and allocated leap 
seconds based on that fit, but alas they do not.

So there is no way to build a clock today that is guaranteed to count 
seconds correctly in future years, short of having it receive leap 
second announcements twice a year and adjust its timekeeping 
accordingly.

-- 

--David Forbes, Tucson, AZ
http://www.cathodecorner.com/


From imp at bsdimp.com  Wed Oct 15 01:13:10 2008
From: imp at bsdimp.com (M. Warner Losh)
Date: Tue, 14 Oct 2008 19:13:10 -0600 (MDT)
Subject: [time-nuts] How many seconds in a year?
In-Reply-To: <a06240500c51aecf2bb80@[192.168.0.24]>
References: <D79C2293-D35E-4D87-8ED7-89A12D01C459@gmail.com>
	<a06240500c51aecf2bb80@[192.168.0.24]>
Message-ID: <20081014.191310.1628361645.imp@bsdimp.com>

In message: <a06240500c51aecf2bb80@[192.168.0.24]>
            David Forbes <dforbes at dakotacom.net> writes:
: So there is no way to build a clock today that is guaranteed to count 
: seconds correctly in future years, short of having it receive leap 
: second announcements twice a year and adjust its timekeeping 
: accordingly.

Unless it has a built-in sundial :-)

Warner

P.S.  And even then only if DUT1 is held < 1s


From namichie at gmail.com  Wed Oct 15 04:53:48 2008
From: namichie at gmail.com (Neville Michie)
Date: Wed, 15 Oct 2008 15:53:48 +1100
Subject: [time-nuts] How many seconds in a year?
In-Reply-To: <20081014.191310.1628361645.imp@bsdimp.com>
References: <D79C2293-D35E-4D87-8ED7-89A12D01C459@gmail.com>
	<a06240500c51aecf2bb80@[192.168.0.24]>
	<20081014.191310.1628361645.imp@bsdimp.com>
Message-ID: <EFBF23B1-1534-4E10-B22C-A17A84BC58F0@gmail.com>

I have been thinking about my problem, the major part of the problem  
is finding the right question.
If leap seconds are applied to keep the meanderings of the planet in  
phase with our mean time
clocks, then what about our leap year days which are applied to keep  
the seasons in phase with our
calendars? Applying a whole day every so many years may keep the  
civil authorities happy,
but when we all celebrate a new year we are not counting down the  
completion of a planetary cycle
but the civil approximation to a new year.
Now, having thought about it a bit more, the year is the completing  
of an orbit of our elliptical orbit around the sun.
The start and finish of an orbit is defined by the inclined axis of  
rotation of the Earth crossing the plane of its orbit which is what  
causes the seasons.
The elliptical orbit is moving, hence the precession of the  
equinoxes. As we can not measure a year
by looking at a particular star crossing our meridian,
we measure the year by watching a fictitious star crossing our  
meridian. This star (which used to be at the first point of Aries
on the vernal equinox) is slowly orbiting around our solar system as  
our tilted ecliptic precesses.

Which now gets me back to my question. If I want to make a clock that  
chimes once per solar year when we have completed a cycle it will  
count down a
number of seconds then chime. So I want to know the number of seconds  
in a Mean Year, accurate enough so that in 200 years time
it will still be right.
It should be fun to see the time the new year really starts as we  
head around the orbit again. The time will not be midnight
but will jump around in the day with different years.
There are so many interference's in time keeping by accountants and  
politicians I was thinking of making a clock that
showed real time as determined by sun and stars.
Although that brings up the equation of time, and mean time is so  
convenient if you have an atomic clock.
I might just try to make a clock that shows the mediaeval "Italian  
Hours", where every day has 24 hours with sunrise at 6 AM with sunset  
at 6PM.
The old clocks had dials marked so that you read off the elastic  
Italian hours.
cheers, Neville Michie

> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ 
> time-nuts
> and follow the instructions there.



From hasweb at has.org.nz  Wed Oct 15 05:07:54 2008
From: hasweb at has.org.nz (hasweb at has.org.nz)
Date: Wed, 15 Oct 2008 18:07:54 +1300
Subject: [time-nuts] How many seconds in a year?
Message-ID: <20081015180754.chk9u1n5cs80wocc@webmail.has.org.nz>

Neville Michie wrote:
> I have been thinking about my problem, the major part of the problem  
>  is finding the right question.
> If leap seconds are applied to keep the meanderings of the planet in  
>  phase with our mean time
> clocks, then what about our leap year days which are applied to keep  
>  the seasons in phase with our
> calendars? Applying a whole day every so many years may keep the   
> civil authorities happy,
> but when we all celebrate a new year we are not counting down the   
> completion of a planetary cycle
> but the civil approximation to a new year.
> Now, having thought about it a bit more, the year is the completing   
> of an orbit of our elliptical orbit around the sun.
> The start and finish of an orbit is defined by the inclined axis of   
> rotation of the Earth crossing the plane of its orbit which is what   
> causes the seasons.
> The elliptical orbit is moving, hence the precession of the   
> equinoxes. As we can not measure a year
> by looking at a particular star crossing our meridian,
> we measure the year by watching a fictitious star crossing our   
> meridian. This star (which used to be at the first point of Aries
> on the vernal equinox) is slowly orbiting around our solar system as  
>  our tilted ecliptic precesses.
> cheers, Neville Michie
>
Neville

There are many definitions of a year all of which differ slightly from  
each other.

You appear to have confused the precession of the equinoxes (better  
described as the precession of the Earth's rotational axis i.e. the  
Earth precesses like a top) with the precession of the apsides of its  
orbit.

Bruce




From jim77742 at gmail.com  Wed Oct 15 05:19:20 2008
From: jim77742 at gmail.com (Jim Palfreyman)
Date: Wed, 15 Oct 2008 16:19:20 +1100
Subject: [time-nuts] How many seconds in a year?
In-Reply-To: <EFBF23B1-1534-4E10-B22C-A17A84BC58F0@gmail.com>
References: <D79C2293-D35E-4D87-8ED7-89A12D01C459@gmail.com>
	<a06240500c51aecf2bb80@192.168.0.24>
	<20081014.191310.1628361645.imp@bsdimp.com>
	<EFBF23B1-1534-4E10-B22C-A17A84BC58F0@gmail.com>
Message-ID: <f616e0f80810142219m18e3ee0x35709d464c1c24@mail.gmail.com>

Hi Neville,

There are a few inaccuracies in your summary but the figure you want for
J2000.0 is 365.242 190 419 SI days=31556925.252202 SI seconds. However we
cannot give you an average over the next 200 years because it is steadily
dropping by 5.324 ms per year. So in 200 years time it will be a second out.

However, for your purposes if you use the number above you will get very
close to what you want.

Regards,

Jim


2008/10/15 Neville Michie <namichie at gmail.com>

> I have been thinking about my problem, the major part of the problem
> is finding the right question.
> If leap seconds are applied to keep the meanderings of the planet in
> phase with our mean time
> clocks, then what about our leap year days which are applied to keep
> the seasons in phase with our
> calendars? Applying a whole day every so many years may keep the
> civil authorities happy,
> but when we all celebrate a new year we are not counting down the
> completion of a planetary cycle
> but the civil approximation to a new year.
> Now, having thought about it a bit more, the year is the completing
> of an orbit of our elliptical orbit around the sun.
> The start and finish of an orbit is defined by the inclined axis of
> rotation of the Earth crossing the plane of its orbit which is what
> causes the seasons.
> The elliptical orbit is moving, hence the precession of the
> equinoxes. As we can not measure a year
> by looking at a particular star crossing our meridian,
> we measure the year by watching a fictitious star crossing our
> meridian. This star (which used to be at the first point of Aries
> on the vernal equinox) is slowly orbiting around our solar system as
> our tilted ecliptic precesses.
>
> Which now gets me back to my question. If I want to make a clock that
> chimes once per solar year when we have completed a cycle it will
> count down a
> number of seconds then chime. So I want to know the number of seconds
> in a Mean Year, accurate enough so that in 200 years time
> it will still be right.
> It should be fun to see the time the new year really starts as we
> head around the orbit again. The time will not be midnight
> but will jump around in the day with different years.
> There are so many interference's in time keeping by accountants and
> politicians I was thinking of making a clock that
> showed real time as determined by sun and stars.
> Although that brings up the equation of time, and mean time is so
> convenient if you have an atomic clock.
> I might just try to make a clock that shows the mediaeval "Italian
> Hours", where every day has 24 hours with sunrise at 6 AM with sunset
> at 6PM.
> The old clocks had dials marked so that you read off the elastic
> Italian hours.
> cheers, Neville Michie
>
> > time-nuts mailing list -- time-nuts at febo.com
> > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/
> > time-nuts
> > and follow the instructions there.
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

From tvb at LeapSecond.com  Wed Oct 15 06:00:29 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Tue, 14 Oct 2008 23:00:29 -0700
Subject: [time-nuts] How many seconds in a year?
References: <D79C2293-D35E-4D87-8ED7-89A12D01C459@gmail.com><a06240500c51aecf2bb80@[192.168.0.24]><20081014.191310.1628361645.imp@bsdimp.com>
	<EFBF23B1-1534-4E10-B22C-A17A84BC58F0@gmail.com>
Message-ID: <001e01c92e8b$54219a70$0500a8c0@pc52>

> Which now gets me back to my question. If I want to make a clock
> that chimes once per solar year when we have completed a cycle
> it will count down a number of seconds then chime. So I want to
> know the number of seconds in a Mean Year, accurate enough
> so that in 200 years time it will still be right.

Neville,

I'm pretty sure no electronic clock ever made is accurate
enough and reliable enough to meet your goal.

But you might want to look at this one, though:

http://www.longnow.org/projects/clock/
http://www.longnow.org/projects/clock/prototype1/
http://www.longnow.org/projects/clock/chimes/

/tvb



From hmurray at megapathdsl.net  Wed Oct 15 06:38:42 2008
From: hmurray at megapathdsl.net (Hal Murray)
Date: Tue, 14 Oct 2008 23:38:42 -0700
Subject: [time-nuts] How many seconds in a year?
In-Reply-To: Message from Neville Michie <namichie@gmail.com> of "Wed,
	15 Oct 2008 15:53:48 +1100."
	<EFBF23B1-1534-4E10-B22C-A17A84BC58F0@gmail.com> 
Message-ID: <20081015063844.112D8BCCE@ip-64-139-1-69.sjc.megapath.net>


> Which now gets me back to my question. If I want to make a clock that
> chimes once per solar year when we have completed a cycle it will
> count down a number of seconds then chime. So I want to know the
> number of seconds   in a Mean Year, accurate enough so that in 200
> years time it will still be right. 

What does "right" mean?

The traditional leap year calculation is good down to (roughly) 1 day per 400 
years.  That's 86400 seconds per 400 years or 216 seconds per year.  Or 
perhaps significantly better.

(Those old geezers had really good telescopes and knew how to drive them.  
One of the proposals fighting for the navigation prize that Harrison 
eventually won was getting time by watching Jupiter's moons.  They even 
corrected for speed of light delays due to relative orbital positions.)

Leap seconds happen every year or so, at least so far.  Who knows what will 
happen tomorrow.  Thats 1/2 % of the leap year corrections.

So what do you mean my "right"?  Do you want legal midnight?  Sidereal 
midnight?  Solar midnight?  ....  How close do you want to be?

200 years is halfway through the 400 year leap cycle, so if you do one 
obvious thing, you will be off roughly 1/2 day.







-- 
These are my opinions, not necessarily my employer's.  I hate spam.





From namichie at gmail.com  Wed Oct 15 09:02:35 2008
From: namichie at gmail.com (Neville Michie)
Date: Wed, 15 Oct 2008 20:02:35 +1100
Subject: [time-nuts] How many seconds in a year?
In-Reply-To: <f616e0f80810142219m18e3ee0x35709d464c1c24@mail.gmail.com>
References: <D79C2293-D35E-4D87-8ED7-89A12D01C459@gmail.com>
	<a06240500c51aecf2bb80@192.168.0.24>
	<20081014.191310.1628361645.imp@bsdimp.com>
	<EFBF23B1-1534-4E10-B22C-A17A84BC58F0@gmail.com>
	<f616e0f80810142219m18e3ee0x35709d464c1c24@mail.gmail.com>
Message-ID: <961E8457-6140-4838-BA68-B06113D8129D@gmail.com>

Thanks Jim,
you told me what I wanted.
We can listen to WWV to hear the stroke of midnight each day, and we  
know it is UTC and
subject to the equation of time but otherwise it represents an exact  
rotation of the planet. We know a day is about
86400.00X seconds long, but a year is rounded to the nearest day,  
what is its real length, as
it is not an integral multiple of days.
Now 12:00:00 is only the end of the civil and legal year and there  
are errors of around 6 hours
each year in rounding it off to the nearest day.
Jim has given the length of a real year (the inverse of the frequency  
of the planet orbit) and
  I would be pleased to ask him another question as to the phase of  
the annual turnover,
what time of day the next annual solstice? occurs.
That is the time for my new year chime to sound,
and Jim has already given the number of seconds to the next chime.
I was not really thinking of leaving an unattended clock running for  
200 years, but it would be nice
to think that I had used the precision available to observe the real  
milestones in time.
I am sorry that this question has been so difficult to ask, but there  
are so many arbitrary distortions
of the observation of time that it has become a very fuzzy concept.
cheers, Neville Michie



On 15/10/2008, at 4:19 PM, Jim Palfreyman wrote:

> Hi Neville,
>
> There are a few inaccuracies in your summary but the figure you  
> want for
> J2000.0 is 365.242 190 419 SI days=31556925.252202 SI seconds.  
> However we
> cannot give you an average over the next 200 years because it is  
> steadily
> dropping by 5.324 ms per year. So in 200 years time it will be a  
> second out.
>
> However, for your purposes if you use the number above you will get  
> very
> close to what you want.
>
> Regards,
>
> Jim
>
>
> 2008/10/15 Neville Michie <namichie at gmail.com>
>
>> I have been thinking about my problem, the major part of the problem
>> is finding the right question.
>> If leap seconds are applied to keep the meanderings of the planet in
>> phase with our mean time
>> clocks, then what about our leap year days which are applied to keep
>> the seasons in phase with our
>> calendars? Applying a whole day every so many years may keep the
>> civil authorities happy,
>> but when we all celebrate a new year we are not counting down the
>> completion of a planetary cycle
>> but the civil approximation to a new year.
>> Now, having thought about it a bit more, the year is the completing
>> of an orbit of our elliptical orbit around the sun.
>> The start and finish of an orbit is defined by the inclined axis of
>> rotation of the Earth crossing the plane of its orbit which is what
>> causes the seasons.
>> The elliptical orbit is moving, hence the precession of the
>> equinoxes. As we can not measure a year
>> by looking at a particular star crossing our meridian,
>> we measure the year by watching a fictitious star crossing our
>> meridian. This star (which used to be at the first point of Aries
>> on the vernal equinox) is slowly orbiting around our solar system as
>> our tilted ecliptic precesses.
>>
>> Which now gets me back to my question. If I want to make a clock that
>> chimes once per solar year when we have completed a cycle it will
>> count down a
>> number of seconds then chime. So I want to know the number of seconds
>> in a Mean Year, accurate enough so that in 200 years time
>> it will still be right.
>> It should be fun to see the time the new year really starts as we
>> head around the orbit again. The time will not be midnight
>> but will jump around in the day with different years.
>> There are so many interference's in time keeping by accountants and
>> politicians I was thinking of making a clock that
>> showed real time as determined by sun and stars.
>> Although that brings up the equation of time, and mean time is so
>> convenient if you have an atomic clock.
>> I might just try to make a clock that shows the mediaeval "Italian
>> Hours", where every day has 24 hours with sunrise at 6 AM with sunset
>> at 6PM.
>> The old clocks had dials marked so that you read off the elastic
>> Italian hours.
>> cheers, Neville Michie
>>
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/
>>> time-nuts
>>> and follow the instructions there.
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ 
> time-nuts
> and follow the instructions there.



From geoff36 at gmail.com  Wed Oct 15 13:08:11 2008
From: geoff36 at gmail.com (Kiwi Geoff)
Date: Thu, 16 Oct 2008 02:08:11 +1300
Subject: [time-nuts] Older Trimble Lassen GPS, can be 1 second out to UTC
Message-ID: <19732ee50810150608t1a159f0bxa0c6c97473accf26@mail.gmail.com>

Hello All,

Just a heads-up for anyone who may be using an older Lassen GPS.

As per this 2005 advisory:   http://tinyurl.com/4dr26y

There are still some Lassens around that have this "pending" bug in 2008.

Regards, Kiwi Geoff (Christchurch, New Zealand).
http://www.geocities.com/kiwi_36_nz/


From brooke at pacific.net  Wed Oct 15 15:19:42 2008
From: brooke at pacific.net (Brooke Clarke)
Date: Wed, 15 Oct 2008 08:19:42 -0700
Subject: [time-nuts] How many seconds in a year?
In-Reply-To: <961E8457-6140-4838-BA68-B06113D8129D@gmail.com>
References: <D79C2293-D35E-4D87-8ED7-89A12D01C459@gmail.com>	<a06240500c51aecf2bb80@192.168.0.24>	<20081014.191310.1628361645.imp@bsdimp.com>	<EFBF23B1-1534-4E10-B22C-A17A84BC58F0@gmail.com>	<f616e0f80810142219m18e3ee0x35709d464c1c24@mail.gmail.com>
	<961E8457-6140-4838-BA68-B06113D8129D@gmail.com>
Message-ID: <48F60A0E.9000102@pacific.net>

Hi Neville:

Leap Years do not occur once every 4 years but are on a more complex schedule.
There's an exception for years that are exact multiples of 100 years.
There's an exception to the exception for years that are exact multiples of 400 
years.  So on a very long term average there are 365.2425 days per year.  See:
http://en.wikipedia.org/wiki/Leapyear
There have been proposals to add a 4000 or 8000 year exception, but that's so 
far in the future and the Earth's rotation has enough variation that these have 
not been made part of the leap year calculations.

The Earth used to be the definition of time but once it was demonstrated that 
Cesium clocks kept much better time they became the definition of the time.  At 
first the length of the second was going to be changed each year "rubber 
seconds", but that was soon discarded and replaced with the leap second.

There are a couple of related areas.  If you have read about or seen the movie 
about Harrison, his clocks and the longitude you know part of the story.

The other is the search for the latitude.  This turns out to be a much more 
complex problem and took a lot longer before there was an understanding of it.
After I moved to Ukiah, CA I discovered there was a street called Observatory 
Ave.  Doing some research at the local Historical house determined it was one 
of six of the Latitude Observatories all located very close to 39:08 deg N.
http://www.prc68.com/I/UkiahObs.shtml

Have Fun,

Brooke Clarke
http://www.prc68.com/P/Prod.html  Products I make and sell
http://www.prc68.com/Alpha.shtml  All my web pages listed based on html name
http://www.PRC68.com
http://www.precisionclock.com
http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Web Cam

Neville Michie wrote:
> Thanks Jim,
> you told me what I wanted.
> We can listen to WWV to hear the stroke of midnight each day, and we  
> know it is UTC and
> subject to the equation of time but otherwise it represents an exact  
> rotation of the planet. We know a day is about
> 86400.00X seconds long, but a year is rounded to the nearest day,  
> what is its real length, as
> it is not an integral multiple of days.
> Now 12:00:00 is only the end of the civil and legal year and there  
> are errors of around 6 hours
> each year in rounding it off to the nearest day.
> Jim has given the length of a real year (the inverse of the frequency  
> of the planet orbit) and
>   I would be pleased to ask him another question as to the phase of  
> the annual turnover,
> what time of day the next annual solstice? occurs.
> That is the time for my new year chime to sound,
> and Jim has already given the number of seconds to the next chime.
> I was not really thinking of leaving an unattended clock running for  
> 200 years, but it would be nice
> to think that I had used the precision available to observe the real  
> milestones in time.
> I am sorry that this question has been so difficult to ask, but there  
> are so many arbitrary distortions
> of the observation of time that it has become a very fuzzy concept.
> cheers, Neville Michie
> 
> 
> 
> On 15/10/2008, at 4:19 PM, Jim Palfreyman wrote:
> 
>> Hi Neville,
>>
>> There are a few inaccuracies in your summary but the figure you  
>> want for
>> J2000.0 is 365.242 190 419 SI days=31556925.252202 SI seconds.  
>> However we
>> cannot give you an average over the next 200 years because it is  
>> steadily
>> dropping by 5.324 ms per year. So in 200 years time it will be a  
>> second out.
>>
>> However, for your purposes if you use the number above you will get  
>> very
>> close to what you want.
>>
>> Regards,
>>
>> Jim
>>
>>
>> 2008/10/15 Neville Michie <namichie at gmail.com>
>>
>>> I have been thinking about my problem, the major part of the problem
>>> is finding the right question.
>>> If leap seconds are applied to keep the meanderings of the planet in
>>> phase with our mean time
>>> clocks, then what about our leap year days which are applied to keep
>>> the seasons in phase with our
>>> calendars? Applying a whole day every so many years may keep the
>>> civil authorities happy,
>>> but when we all celebrate a new year we are not counting down the
>>> completion of a planetary cycle
>>> but the civil approximation to a new year.
>>> Now, having thought about it a bit more, the year is the completing
>>> of an orbit of our elliptical orbit around the sun.
>>> The start and finish of an orbit is defined by the inclined axis of
>>> rotation of the Earth crossing the plane of its orbit which is what
>>> causes the seasons.
>>> The elliptical orbit is moving, hence the precession of the
>>> equinoxes. As we can not measure a year
>>> by looking at a particular star crossing our meridian,
>>> we measure the year by watching a fictitious star crossing our
>>> meridian. This star (which used to be at the first point of Aries
>>> on the vernal equinox) is slowly orbiting around our solar system as
>>> our tilted ecliptic precesses.
>>>
>>> Which now gets me back to my question. If I want to make a clock that
>>> chimes once per solar year when we have completed a cycle it will
>>> count down a
>>> number of seconds then chime. So I want to know the number of seconds
>>> in a Mean Year, accurate enough so that in 200 years time
>>> it will still be right.
>>> It should be fun to see the time the new year really starts as we
>>> head around the orbit again. The time will not be midnight
>>> but will jump around in the day with different years.
>>> There are so many interference's in time keeping by accountants and
>>> politicians I was thinking of making a clock that
>>> showed real time as determined by sun and stars.
>>> Although that brings up the equation of time, and mean time is so
>>> convenient if you have an atomic clock.
>>> I might just try to make a clock that shows the mediaeval "Italian
>>> Hours", where every day has 24 hours with sunrise at 6 AM with sunset
>>> at 6PM.
>>> The old clocks had dials marked so that you read off the elastic
>>> Italian hours.
>>> cheers, Neville Michie
>>>
>>>> time-nuts mailing list -- time-nuts at febo.com
>>>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/
>>>> time-nuts
>>>> and follow the instructions there.
>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to
>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ 
>> time-nuts
>> and follow the instructions there.
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 


From dforbes at dakotacom.net  Wed Oct 15 15:51:56 2008
From: dforbes at dakotacom.net (David Forbes)
Date: Wed, 15 Oct 2008 08:51:56 -0700
Subject: [time-nuts] Jeopardy questions
In-Reply-To: <961E8457-6140-4838-BA68-B06113D8129D@gmail.com>
References: <D79C2293-D35E-4D87-8ED7-89A12D01C459@gmail.com>
	<a06240500c51aecf2bb80@192.168.0.24>
	<20081014.191310.1628361645.imp@bsdimp.com>
	<EFBF23B1-1534-4E10-B22C-A17A84BC58F0@gmail.com>
	<f616e0f80810142219m18e3ee0x35709d464c1c24@mail.gmail.com>
	<961E8457-6140-4838-BA68-B06113D8129D@gmail.com>
Message-ID: <a06240500c51bc0c8619e@[192.168.0.24]>

At 8:02 PM +1100 10/15/08, Neville Michie wrote:
>I am sorry that this question has been so difficult to ask, but there
>are so many arbitrary distortions
>of the observation of time that it has become a very fuzzy concept.
>cheers, Neville Michie

It is perhaps phrased best as a Jeopardy question. (Jeopardy is a TV 
game show in which the answers are phrased as questions to match the 
questions which are phrased as answers.)

Q: 31556925.252202
A: What is the orbital period of the Earth in seconds?

Q: It depends on a lot of things political and earthly
A: How many seconds are there in a year?

It is indeed amusing how the word "year" so muddies this simple 
parameter of celestial mechanics, by inserting politics into the 
question.

-- 

--David Forbes, Tucson, AZ
http://www.cathodecorner.com/


From msokolov at ivan.Harhan.ORG  Wed Oct 15 17:23:53 2008
From: msokolov at ivan.Harhan.ORG (Michael Sokolov)
Date: Wed, 15 Oct 2008 17:23:53 GMT
Subject: [time-nuts] How many seconds in a year?
Message-ID: <0810151723.AA25364@ivan.Harhan.ORG>

Neville Michie <namichie at gmail.com> wrote:

> If leap seconds are applied to keep the meanderings of the planet in  
> phase with our mean time
> clocks, then what about our leap year days which are applied to keep  
> the seasons in phase with our
> calendars? Applying a whole day every so many years may keep the  
> civil authorities happy,
> but when we all celebrate a new year we are not counting down the  
> completion of a planetary cycle
> but the civil approximation to a new year.

I have developed an alternate calendar which fixes this problem:

http://ivan.Harhan.ORG/RT/calendar/spec.txt

Today is SE 47 Vnd 29, which means day 29 of Vendemiaire of year 47 of
Space Era.

MS


From mfeher at eozinc.com  Thu Oct 16 13:30:12 2008
From: mfeher at eozinc.com (Mike Feher)
Date: Thu, 16 Oct 2008 09:30:12 -0400
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
In-Reply-To: <005401c92e34$71099400$0500a8c0@pc52>
References: <33928620-888F-48A0-9F52-6427F5F0BEED@gmail.com><5A4EFAE4A47A4D428BED3350ECF22BED@didierhp><768835EB-4675-4E19-8971-7C2C9098ADA6@gmail.com><03A6F2CF0F504F9DA5B0D8F919CEBDDB@didierhp><2D3C7CD387614F5F8D3521363034E0F0@gsmacdq14es>
	<005401c92e34$71099400$0500a8c0@pc52>
Message-ID: <67E2746398D344658B2DE2009F2BE862@gsmacdq14es>

Tom -

I am pretty sure I could get you a loaner Mini-T to evaluate if you are
willing to do so. I may also be able to get a new Vectron, if you would like
to look at it as well. Let me know. Regards - Mike

 
 
Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960
 
 
-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Tom Van Baak
Sent: Tuesday, October 14, 2008 3:38 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Frequency Stability of Trimble Mini-T

Mike,

I keep hoping to find a Mini-T on eBay but no luck yet and so I
don't have plots on my web site for that unit. Does anyone have
a loaner?

Question on the spec and on your plot, though. What is the gate
time of the frequency measurements? If you average for an hour
or a day many of those peaks would melt.

Also most look like phase jumps not frequency jumps. When you
see frequency jump up and then down by the same amount as a
pair it's usually the result of a single phase jump.

Did you log sats-in-view, or DOP, or temp during your run to see
if the jumps correlated to that?

Finally, "frequency drift" is not at all the same thing as "frequency
excursions", so what did they really mean?

/tvb

> The attached URL is a 11 day plot of a 30.5 GHz carrier taken every minute
> by an Agilent 53152A microwave counter. The Mini-T has an ovenized
> oscillator. It appears that the GPS attempts to over correct the
oscillator,
> hence the large frequency excursions. The real large excursions, around
the
> 96 hour range, were due to a loose connector. The requirements are such
that
> over a 90 day period the total frequency drift shall be no more than 1
KHz.
> Someone in their ultimate wisdom, decided that since they do not have the
> time to take measurements for 90 days, they will take it for 24 hours and
> not allow any frequency excursions over 11 Hz at 30.5 GHz. Obviously, this
> plot does not pass their requirement. When the oscillator is allowed to
free
> run, the frequency jumps are not there. Has any one else made any
> measurements on the Trimble Mini-T. Any observations or suggestions are
> appreciated. Regards - Mike
> 
> http://www.eozinc.com/11dayplot.pdf
> 
> 
> Mike B. Feher, N4FS
> 89 Arnold Blvd.
> Howell, NJ, 07731
> 732-886-5960



_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



From SAIDJACK at aol.com  Thu Oct 16 16:40:07 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Thu, 16 Oct 2008 12:40:07 EDT
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
Message-ID: <c26.478efd5a.3628c867@aol.com>

Hello Mike, Tom,
 
just came across your post. This looks to me like a classical crystal  
frequency jump that the unit is compensating for. Looks like the Mini-t is a bit  
under-damped in it's response.
 
John Vig talks about these jumps in his paper, and he mentions that  the root 
causes are not well understood. One way to verify this is to plot the  EFC 
voltage (not sure if this can be done on the Mini-t), and see if it "jumps",  
similar to the plots in the Vig paper.
 
Co-incidentally we have developed a unit for this same Army requirement  
(11Hz requirement), and early on had seen a similar issue which we solved, and  we 
can now easily meet this requirement. Let me know if you would like more  
details, we can provide these offline.
 
Typically crystals jump <1ppb, but I have seen worse. That busts the  11Hz 
requirement of course. With GPS disciplining, these jumps can now  easily be 
seen. "Curing" the jumps is a combination of crystal blank processing,  testing, 
burn-in, and other factors. There is no easy solution.
 
You actually have stumbled upon an area where, as well documented as  Quartz 
oscillators are, there is quite a lack of documentation and research in  my 
opinion.
 
One note: some of the time nuts had received E1938A' units that  had tags on 
them saying "crystal jumps", so this problem happens in the best  families :)
 
bye,
Said
 
 
 
In a message dated 10/14/2008 17:13:04 Pacific Daylight Time,  
mfeher at eozinc.com writes:

Tom  -



Thanks for your reply. I was not present during the testing.  In my opinion,
and now I have been able to convince others, the contractor  passed the test,
which is derived from MIL-STD-118-164ACN2. The main  specification states the
following:



5.1.2.5 Carrier  frequency accuracy. The carrier frequency accuracy at the
antenna feed  shall be within 1 KHz of the intended value for all RF
carriers.  Recalibration intervals to maintain this accuracy shall not be
less than 90  days. 



This is on an Army satellite terminal. Another branch of  the Army came up
with the 11 Hz requirement over 24 hours (for testing  purposes), which is
just 1KHz/90, and I feel it is total rubbish.  I  myself have been trying to
find out the gate time used on the counter, but  have not been abler to get
it yet and not sure I will. Needles to say,  using the stated counter, and
logging a measurement at one minute intervals  with a resulting readout down
to 1 Hz at 30 GHz, probably does not leave  too many options for gate time.
The jumps do not exactly come in pairs,  although they seem to, but, remember
there are close to 16,000 points on  that graph. I agree with you that
averaging would make the plot into a  straight line. 





From mfeher at eozinc.com  Thu Oct 16 17:38:12 2008
From: mfeher at eozinc.com (Mike Feher)
Date: Thu, 16 Oct 2008 13:38:12 -0400
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
In-Reply-To: <c26.478efd5a.3628c867@aol.com>
References: <c26.478efd5a.3628c867@aol.com>
Message-ID: <EB95CE089B7644A287FEF883A36C0664@gsmacdq14es>

Said -

To date there has been no data taken just on the EFC to see if there is any
correlation. However, late last year a test was run for about 11 days on the
Mini-T, without the antenna connected, and a slow downward drift was
evident. In fact, the drift was such that the 11 Hz requirement, at 30 GHz,
was easily met even though there may have been noise on the EFC. Like I said
previously, I am in the process of fighting the 11 Hz requirement as I
believe it is totally unrealistic. Even the spec of 1 KHz is unrealistic at
the high data rates being used. But, since that can be easily met, at least
for the time being, I am not ready to tackle that issue. I did receive one
of those 1938A units from Rick, but have not had a chance to play with it
yet. 

I think I mentioned in a previous post that John did contact me over the
weekend and told me he retired 2 years ago. Now he is too involved with his
new post as President of the IEEE starting in 2009. I was hoping he could
help me fight this battle. We worked on some of the same issues together on
and off in the last 25 or so years. 

I would definitely be interested in your unit. I assume then that it was
also for a terminal to be used with the AF WGS satellite. Regards - Mike

 
 
Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960
 
 

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of SAIDJACK at aol.com
Sent: Thursday, October 16, 2008 12:40 PM
To: time-nuts at febo.com; tvb at leapsecond.com
Subject: Re: [time-nuts] Frequency Stability of Trimble Mini-T

Hello Mike, Tom,
 
just came across your post. This looks to me like a classical crystal  
frequency jump that the unit is compensating for. Looks like the Mini-t is a
bit  
under-damped in it's response.
 
John Vig talks about these jumps in his paper, and he mentions that  the
root 
causes are not well understood. One way to verify this is to plot the  EFC 
voltage (not sure if this can be done on the Mini-t), and see if it "jumps",

similar to the plots in the Vig paper.
 
Co-incidentally we have developed a unit for this same Army requirement  
(11Hz requirement), and early on had seen a similar issue which we solved,
and  we 
can now easily meet this requirement. Let me know if you would like more  
details, we can provide these offline.
 
Typically crystals jump <1ppb, but I have seen worse. That busts the  11Hz 
requirement of course. With GPS disciplining, these jumps can now  easily be

seen. "Curing" the jumps is a combination of crystal blank processing,
testing, 
burn-in, and other factors. There is no easy solution.
 
You actually have stumbled upon an area where, as well documented as  Quartz

oscillators are, there is quite a lack of documentation and research in  my 
opinion.
 
One note: some of the time nuts had received E1938A' units that  had tags on

them saying "crystal jumps", so this problem happens in the best  families
:)
 
bye,
Said
 
 
 
In a message dated 10/14/2008 17:13:04 Pacific Daylight Time,  
mfeher at eozinc.com writes:

Tom  -



Thanks for your reply. I was not present during the testing.  In my opinion,
and now I have been able to convince others, the contractor  passed the
test,
which is derived from MIL-STD-118-164ACN2. The main  specification states
the
following:



5.1.2.5 Carrier  frequency accuracy. The carrier frequency accuracy at the
antenna feed  shall be within 1 KHz of the intended value for all RF
carriers.  Recalibration intervals to maintain this accuracy shall not be
less than 90  days. 



This is on an Army satellite terminal. Another branch of  the Army came up
with the 11 Hz requirement over 24 hours (for testing  purposes), which is
just 1KHz/90, and I feel it is total rubbish.  I  myself have been trying to
find out the gate time used on the counter, but  have not been abler to get
it yet and not sure I will. Needles to say,  using the stated counter, and
logging a measurement at one minute intervals  with a resulting readout down
to 1 Hz at 30 GHz, probably does not leave  too many options for gate time.
The jumps do not exactly come in pairs,  although they seem to, but,
remember
there are close to 16,000 points on  that graph. I agree with you that
averaging would make the plot into a  straight line. 




_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



From SAIDJACK at aol.com  Thu Oct 16 18:18:29 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Thu, 16 Oct 2008 14:18:29 EDT
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
Message-ID: <d17.381bf835.3628df75@aol.com>

Hello Mike,
 
the problem is one of statistics. Not all crystals exhibit this, one may  
find only about 20% or so of a typical manufacturers OCXO will exhibit these  
jumps, and with varying intensity. So unless these are directly addressed at the  
factory (which does not seem to be the case for the Mini-T), then some units 
may  meet spec, while others won't, and there is no way to tell the 
difference. As  far as I know, there is no OCXO vendor that by default tests their 
product for  these jumps during production.
 
I think you may be fighting an uphill battle to try to have the Army change  
their specs :) We don't understand some of these specs either, but decided  to 
just meet them rather than trying to get them to change their ways. In the  
process we were able to find and design IP that gives us a slight edge.
 
 
Due to confidentiality, I can't comment much online on the GPSDO we  did for 
this particular application other than that it is based on our  FireFly-II 
GPSDO; but will contact you offline.
 

On the EFC drift you had seen in holdover on the Mini-t: there would be no  
correlation between EFC voltage and jumps without having GPS active, since the  
crystal will just change frequency without the firmware ever knowing anything 
 about this change. So the EFC voltage would stay constant while in holdover, 
 while the output frequency may vary.
 
But with GPS enabled, the unit would immediately see the phase shift  
(frequency error), and start correcting for it. This correction is what we can  see. 
The crystal may require a slightly different EFC voltage after the  jump to 
generate 10.0MHz because something physically changed in the crystal  (such as a 
mechanical stress relief, particles leaving/reaching the quartz,  etc). This 
voltage difference can be between 50 microvolts, all the way up to  several 
millivolts.
 
bye,
Said
 
 
In a message dated 10/16/2008 10:49:45 Pacific Daylight Time,  
mfeher at eozinc.com writes:

Said  -

To date there has been no data taken just on the EFC to see if there  is any
correlation. However, late last year a test was run for about 11  days on the
Mini-T, without the antenna connected, and a slow downward  drift was
evident. In fact, the drift was such that the 11 Hz requirement,  at 30 GHz,
was easily met even though there may have been noise on the EFC.  Like I said
previously, I am in the process of fighting the 11 Hz  requirement as I
believe it is totally unrealistic. Even the spec of 1 KHz  is unrealistic at
the high data rates being used. But, since that can be  easily met, at least
for the time being, I am not ready to tackle that  issue. I did receive one
of those 1938A units from Rick, but have not had a  chance to play with it
yet. 

I think I mentioned in a previous post  that John did contact me over the
weekend and told me he retired 2 years  ago. Now he is too involved with his
new post as President of the IEEE  starting in 2009. I was hoping he could
help me fight this battle. We  worked on some of the same issues together on
and off in the last 25 or so  years. 

I would definitely be interested in your unit. I assume then  that it was
also for a terminal to be used with the AF WGS satellite.  Regards - Mike



Mike B. Feher, N4FS
89 Arnold  Blvd.
Howell, NJ,  07731
732-886-5960



From hmurray at megapathdsl.net  Thu Oct 16 18:29:15 2008
From: hmurray at megapathdsl.net (Hal Murray)
Date: Thu, 16 Oct 2008 11:29:15 -0700
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
In-Reply-To: Message from SAIDJACK@aol.com 
	of "Thu, 16 Oct 2008 14:18:29 EDT." <d17.381bf835.3628df75@aol.com> 
Message-ID: <20081016182916.2BE63BCD4@ip-64-139-1-69.sjc.megapath.net>


> the problem is one of statistics. Not all crystals exhibit this, one
> may find only about 20% or so of a typical manufacturers OCXO will
> exhibit these jumps, and with varying intensity. 

There is another dimension.  How often do the jumps happen?

Do the other 80% make jumps if you wait longer?


-- 
These are my opinions, not necessarily my employer's.  I hate spam.





From XDE-L2G3 at myamail.com  Thu Oct 16 19:19:56 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Thu, 16 Oct 2008 15:19:56 -0400
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
References: <d17.381bf835.3628df75@aol.com>
Message-ID: <mailman.3.1224184828.2504.time-nuts@febo.com>

  SAIDJACK at aol.com wrote:

  [...]

  > Due to  confidentiality, I can't comment much online on  the GPSDO
  > we did for this particular application other than that it is based
  > on our FireFly-II GPSDO; but will contact you offline.

  [...]

  > The crystal may require a slightly different EFC voltage after the
  > jump to  generate 10.0MHz because something physically  changed in
  > the crystal  (such  as   a   mechanical  stress  relief, particles
  > leaving/reaching the quartz, etc). This voltage difference  can be
  > between 50 microvolts, all the way up to several millivolts.

  >  bye,
  >  Said

  Said,

  Do you mind if I ask some questions?

  When you say the EFC voltage changes by several millivolts, how much
  does that change the crystal frequency?

  if it is not confidential, can you say what kind of  phase detection
  you use in your GPSDO?

  On your page at http://www.jackson-labs.com/products_fury.html

  it states:

  "Allan Deviations  of less than 1E-011 are possible  for measurement
  intervalls greater than 0.1 seconds."

  What kind of counter do you use to measure that data point?

  Further down on the same page, it states:

  "A high-end Motorola GPS receiver"

  Can you tell what kind of Motorola GPS you use?

  Finally, do  you  have  a  price list  for  the  OEM  and commercial
  products?

  Thanks,

  Best Regards

  Mike Monett


From SAIDJACK at aol.com  Thu Oct 16 19:21:29 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Thu, 16 Oct 2008 15:21:29 EDT
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
Message-ID: <bc0.42895af3.3628ee39@aol.com>

Hi there,
 
exactly! What about units that jump only once every say 12 months or  so?
 
I can't find much fundamental research on this at all; and if even Mr. Vig  
says the phenomenon is not well understood.. But there are (propriatary) ways 
to  probe for the susceptibility of a particular unit to do this.
 
We have done some extensive research trying to correlate jumps to external  
phenomena (radiation, vibration, thermal effects, etc). There is no straight  
forward correlation.
 
It's similar to asynchronous switching inside a digital computer. You can  
add levels of flip flops to synchronize across two asynchronous time-domains,  
but all you are doing is decreasing the possibility of a meta-stable failure to 
 make it through the flops. Statistically you can never guarantee that there  
won't be a failure at all; even if the MTBF is 10 Million years by using five 
 levels of synchronization etc, a failure could actually happen after 10s of  
operation.
 
The good news is: there are mitigating factors. Most jumps are in the  E-011 
or E-010 range, and most applications won't even be affected by such  an 
extremely small frequency change, and we have GPS to quickly correct the  
aberration.
 
I would not be surprised if your standard computer crystal has jumps in the  
range of E-07 that happen all the time, and no one notices.
 
As Mike said, most specs that require performance of E-010 or better are  
somewhat bogus, and don't have real-world requirements that come close  to the 
paper spec. So we try to improve the state of the art as best as we  can.
 
bye,
Said
 
 
In a message dated 10/16/2008 11:31:32 Pacific Daylight Time,  
hmurray at megapathdsl.net writes:


>  the problem is one of statistics. Not all crystals exhibit this, one
>  may find only about 20% or so of a typical manufacturers OCXO will
>  exhibit these jumps, and with varying intensity. 

There is another  dimension.  How often do the jumps happen?

Do the other 80% make  jumps if you wait longer?




From tvb at LeapSecond.com  Thu Oct 16 19:36:12 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Thu, 16 Oct 2008 12:36:12 -0700
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
References: <bc0.42895af3.3628ee39@aol.com>
Message-ID: <000701c92fc6$7276ace0$0500a8c0@pc52>

> I can't find much fundamental research on this at all; and if even Mr. Vig  
> says the phenomenon is not well understood.. But there are (propriatary) ways 
> to  probe for the susceptibility of a particular unit to do this.

John told me once that an easy way to deal with many classes
of jumps is simply use a pair of OCXO. This is an easy solution
for a time-nut (driven by interest and passion), perhaps much
less so for a manufacturer (driven by market and profit).

If we as a group find that unpredictable phase or frequency
jumps are limiting GPSDO performance then that would be a
fun group discussion on how best to implement a N-way XO
GPSDO. If done to the extreme it could also reduce phase
noise as a by-product.

But let's not jump (!) to conclusions that Mike's problem is
necessarily all quartz related. Given how little testing any of
us have done on this particular GPSDO, speculation should
take a back seat to measurement.

/tvb



From SAIDJACK at aol.com  Thu Oct 16 20:23:31 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Thu, 16 Oct 2008 16:23:31 EDT
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
Message-ID: <c0f.3b1778db.3628fcc3@aol.com>

Hello Mike,
 
let me take the commercial discussion offline with you, and let me try to  
answer the time-nuts questions for you:
 
>  When you say the EFC voltage changes by several millivolts,  how much
>  does that change the crystal frequency?


Actually, the average frequency doesn't change at all, it is being  held at 
10.0MHz by the GPS reference. What does change is the control voltage  that the 
crystal wants to see to generate exactly 10.0MHz.
 
But let's say you kept the EFC voltage constant, say by disconnecting  the 
GPS antenna, then it is simple to calculate the frequency change the OCXO  
experienced due to the jump:
 
   Say there was a 500 Microvolts jump. A typical OCXO has  +/-20Hz control 
range 0V to 5V. So it's sensitivity is 8Hz/V. Now simply  multiply this by 
0.5mV:
 
   8Hz/V * 0.5mV = 0.004Hz change of frequency
 
Or in other words, 0.004Hz/10MHz = 4E-010 change in frequency.
 
That doesn't sound significant, but would show up as a significant jump  on 
GPSCon for example.

>  if it is not confidential, can you say what kind of   phase detection
>  you use in your GPSDO?


That's a little bit confidential unfortunately :) 

>  On your page at  http://www.jackson-labs.com/products_fury.html
>  it  states:
>  "Allan Deviations  of less than 1E-011 are  possible  for measurement
>  intervalls greater than 0.1  seconds."
>  What kind of counter do you use to measure that data  point?


You can find several review papers of Jackson Labs' products written by Tom  
Van Baak on his website. He was kind enough to supply ADEV plots for our  Fury 
units, and our double oven units achieve this level of performance. I  think 
he used 53132A's for some of these plots, and TSC5120A units for the ADEV  
plots.
 
See for example his review of an early version of the Fury:
 
   _http://www.leapsecond.com/pages/fury/_ 
(http://www.leapsecond.com/pages/fury/) 
 
Please note that Tom tested an early version of the Fury firmware, and we  
have since very significantly improved the performance of the unit.

>  Further down on the same page, it states:
>  "A  high-end Motorola GPS receiver"
>  Can you tell what kind of Motorola  GPS you use?


Fury uses the M12+ and/or M12M GPS. They are now made by iLotus since  
Motorola sold their GPS operations. We also use modern 3D-capable 50-channel  GPS's 
on our newer products such as the FireFly series GPSDO.

>Finally, do  you  have  a  price list   for  the  OEM  and commercial 
products?


I will have our VP of sales discuss this with you, and send you a price  list 
offline.
 
Thanks,
Said



From jmiles at pop.net  Thu Oct 16 21:27:20 2008
From: jmiles at pop.net (John Miles)
Date: Thu, 16 Oct 2008 14:27:20 -0700
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
In-Reply-To: <bc0.42895af3.3628ee39@aol.com>
Message-ID: <PKEGJHPHLLBACEOICCBJGEAAMOAB.jmiles@pop.net>

Couple of (somewhat naive) questions here:

> It's similar to asynchronous switching inside a digital computer.
> You can
> add levels of flip flops to synchronize across two asynchronous
> time-domains,
> but all you are doing is decreasing the possibility of a
> meta-stable failure to
>  make it through the flops. Statistically you can never guarantee
> that there
> won't be a failure at all; even if the MTBF is 10 Million years
> by using five
>  levels of synchronization etc, a failure could actually happen
> after 10s of
> operation.

Well, no, proper domain synchronization doesn't just give you an incremental
advantage.  The use of flip-flops between clock domains is done to trade
latency for guaranteed stability.  The idea is to isolate the effects of
metastability to a single clock edge that won't be used to clock anything
else.  Unless a metastable event somehow lasts more than one clock period
(or half-period) it won't constitute a failure... and that never happens in
practice, in the absence of a hard failure.  Correct?  Or am I missing
something?  (e.g., are we talking cosmic-ray hits, which are much more
likely to affect RAM elements than clock synchronizers?)

> The good news is: there are mitigating factors. Most jumps are in
> the  E-011
> or E-010 range, and most applications won't even be affected by such  an
> extremely small frequency change, and we have GPS to quickly correct the
> aberration.

Is it a good idea to tie a crystal to GPS with such a wide loop bandwidth?
GPS-locked loops are usually on the order of t=1 minute, right?  Or do you
use 'speedup' tricks to temporarily widen the loop bandwidth when you see a
fast transition?  That sounds reasonable as long as there aren't any GPS
propagation aberrations or timing-receiver artifacts that can't be
distinguished from a crystal jump.

-- john, KE5FX



From jmiles at pop.net  Thu Oct 16 21:36:01 2008
From: jmiles at pop.net (John Miles)
Date: Thu, 16 Oct 2008 14:36:01 -0700
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
In-Reply-To: <000701c92fc6$7276ace0$0500a8c0@pc52>
Message-ID: <PKEGJHPHLLBACEOICCBJCEAFMOAB.jmiles@pop.net>


> > I can't find much fundamental research on this at all; and if
> even Mr. Vig
> > says the phenomenon is not well understood.. But there are
> (propriatary) ways
> > to  probe for the susceptibility of a particular unit to do this.
>
> John told me once that an easy way to deal with many classes
> of jumps is simply use a pair of OCXO. This is an easy solution
> for a time-nut (driven by interest and passion), perhaps much
> less so for a manufacturer (driven by market and profit).

Hmm, it's worth considering how good the secondary oscillator really needs
to be.  If the jumps tend to occur once per minute in a cheap oscillator and
once per hour in a good one, and if they're truly uncorrelated, then it
might be reasonable to detect jumps in either oscillator by differentiating
the beat note between the cheap and expensive rocks.  A third cheap
oscillator would be used to 'vote' on which one was responsible for the
observed jump.

You would only need oscillators of equal quality if you wanted to improve
ADEV and/or PN performance across the board.  Detecting fast excursions
should in principle be much easier.

-- john, KE5FX




From james.p.lux at jpl.nasa.gov  Thu Oct 16 22:18:09 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Thu, 16 Oct 2008 15:18:09 -0700
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
In-Reply-To: <PKEGJHPHLLBACEOICCBJGEAAMOAB.jmiles@pop.net>
References: <bc0.42895af3.3628ee39@aol.com>
	<PKEGJHPHLLBACEOICCBJGEAAMOAB.jmiles@pop.net>
Message-ID: <ECE7A93BD093E1439C20020FBE87C47FEB523ED2DD@ALTPHYEMBEVSP20.RES.AD.JPL>

>
> Well, no, proper domain synchronization doesn't just give you
> an incremental advantage.  The use of flip-flops between
> clock domains is done to trade latency for guaranteed
> stability.  The idea is to isolate the effects of
> metastability to a single clock edge that won't be used to
> clock anything else.  Unless a metastable event somehow lasts
> more than one clock period (or half-period) it won't
> constitute a failure... and that never happens in practice,
> in the absence of a hard failure.  Correct?  Or am I missing
> something?  (e.g., are we talking cosmic-ray hits, which are
> much more likely to affect RAM elements than clock synchronizers?)
>


A flipflop used as a synchronizer *is* a RAM element subject to upset, albeit one that can be made quite robust with internal redundancy.

Even without TMR or other similar schemes, the probability of upset IS pretty low. However, as Black or Scholes said(I can't remember which), "One should not confuse very low probability with impossible". If it absolutely, positively can't take any hit, then some more work is involved.

James Lux, P.E.
Task Manager, SOMD Software Defined Radios
Flight Communications Systems Section
Jet Propulsion Laboratory
4800 Oak Grove Drive, Mail Stop 161-213
Pasadena, CA, 91109
+1(818)354-2075 phone
+1(818)393-6875 fax


From hmurray at megapathdsl.net  Thu Oct 16 22:40:12 2008
From: hmurray at megapathdsl.net (Hal Murray)
Date: Thu, 16 Oct 2008 15:40:12 -0700
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
In-Reply-To: Message from SAIDJACK@aol.com 
	of "Thu, 16 Oct 2008 15:21:29 EDT." <bc0.42895af3.3628ee39@aol.com> 
Message-ID: <20081016224013.24B75BCD4@ip-64-139-1-69.sjc.megapath.net>


> We have done some extensive research trying to correlate jumps to
> external phenomena (radiation, vibration, thermal effects, etc).
> There is no straight forward correlation.

> It's similar to asynchronous switching inside a digital computer.
> You can add levels of flip flops to synchronize across two
> asynchronous time-domains,  ...

I think that's misleading in two ways.

First, we understand metastability.  We can measure it and predict it.  It it 
mattered, we could test each individual part.

Second, the failure mode is exponential in a parameter we can control.  So 
given a particular set of parts to pick from, it's reasonable to make a 
design with a probability of error small enough so that other things are much 
more important.


> If it absolutely, positively can't take any hit, then some more work is involved

I would say that the first step is to put a number on "absolutely, 
positively".

If you aren't willing to take some risk, you won't get off the drawing board.



-- 
These are my opinions, not necessarily my employer's.  I hate spam.





From XDE-L2G3 at myamail.com  Thu Oct 16 22:50:37 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Thu, 16 Oct 2008 18:50:37 -0400
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
References: <bc0.42895af3.3628ee39@aol.com>
	<PKEGJHPHLLBACEOICCBJGEAAMOAB.jmiles@pop.net>
	<ECE7A93BD093E1439C20020FBE87C47FEB523ED2DD@ALTPHYEMBEVSP20.RES.AD.JPL>
Message-ID: <mailman.4.1224197447.2504.time-nuts@febo.com>

  "Lux, James P" <james.p.lux at jpl.nasa.gov> wrote:

  [...]

  > Even without  TMR  or other similar  schemes,  the  probability of
  > upset IS  pretty low. However, as Black or Scholes  said  (I can't
  > remember which), "One should not confuse very low probability with
  > impossible". If it absolutely, positively can't take any hit, then
  > some more work is involved.

  > James Lux, P.E.

  How do you do that? Any web links to study?

  As far  as I know, it is impossible to absolutely  guarantee against
  metastability. Do you wait a week for the metastability to settle?

  If zero probability of failure is so important, you would  also have
  to include  the  probability of a solder joint  opening,  or  a chip
  failing due  to metal migration or latent ESD damage. That  is never
  zero.

  Of course, after the system is perfect, someone will take it and put
  it on a destroyer running Windows:)

  Best Regards,

  Mike Monett


From hasweb at has.org.nz  Thu Oct 16 23:05:41 2008
From: hasweb at has.org.nz (hasweb at has.org.nz)
Date: Fri, 17 Oct 2008 12:05:41 +1300
Subject: [time-nuts] Fwd: Re:  Frequency Stability of Trimble Mini-T
Message-ID: <20081017120541.x20q9o4cusscs0os@webmail.has.org.nz>



----- Forwarded message from hasweb at has.org.nz -----
     Date: Fri, 17 Oct 2008 12:02:48 +1300
     From: hasweb at has.org.nz
Reply-To: hasweb at has.org.nz
  Subject: Re: [time-nuts] Frequency Stability of Trimble Mini-T
       To: Mike Monett <XDE-L2G3 at myamail.com>

Quoting Mike Monett <XDE-L2G3 at myamail.com>:

>   "Lux, James P" <james.p.lux at jpl.nasa.gov> wrote:
>
>   [...]
>
>   > Even without  TMR  or other similar  schemes,  the  probability of
>   > upset IS  pretty low. However, as Black or Scholes  said  (I can't
>   > remember which), "One should not confuse very low probability with
>   > impossible". If it absolutely, positively can't take any hit, then
>   > some more work is involved.
>
>   > James Lux, P.E.
>
>   How do you do that? Any web links to study?
>
>   As far  as I know, it is impossible to absolutely  guarantee against
>   metastability. Do you wait a week for the metastability to settle?
>
>   If zero probability of failure is so important, you would  also have
>   to include  the  probability of a solder joint  opening,  or  a chip
>   failing due  to metal migration or latent ESD damage. That  is never
>   zero.
>
>   Of course, after the system is perfect, someone will take it and put
>   it on a destroyer running Windows:)
>
>   Best Regards,
>
>   Mike Monett
>
> _______________________________________________
>
Mike

You could always look at: United States Patent US4820939.
But dont bet on it.

Bruce



----- End forwarded message -----




From james.p.lux at jpl.nasa.gov  Thu Oct 16 23:15:40 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Thu, 16 Oct 2008 16:15:40 -0700
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
In-Reply-To: <E1Kqbg6-0007uB-Nh@meow.febo.com>
References: <bc0.42895af3.3628ee39@aol.com>
	<PKEGJHPHLLBACEOICCBJGEAAMOAB.jmiles@pop.net>
	<ECE7A93BD093E1439C20020FBE87C47FEB523ED2DD@ALTPHYEMBEVSP20.RES.AD.JPL>
	<E1Kqbg6-0007uB-Nh@meow.febo.com>
Message-ID: <ECE7A93BD093E1439C20020FBE87C47FEB523ED2E5@ALTPHYEMBEVSP20.RES.AD.JPL>



James Lux, P.E.
Task Manager, SOMD Software Defined Radios
Flight Communications Systems Section
Jet Propulsion Laboratory
4800 Oak Grove Drive, Mail Stop 161-213
Pasadena, CA, 91109
+1(818)354-2075 phone
+1(818)393-6875 fax

> -----Original Message-----
> From: time-nuts-bounces at febo.com
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Mike Monett
> Sent: Thursday, October 16, 2008 3:51 PM
> To: time-nuts at febo.com
> Subject: Re: [time-nuts] Frequency Stability of Trimble Mini-T
>
>   "Lux, James P" <james.p.lux at jpl.nasa.gov> wrote:
>
>   [...]
>
>   > Even without  TMR  or other similar  schemes,  the  probability of
>   > upset IS  pretty low. However, as Black or Scholes  said  (I can't
>   > remember which), "One should not confuse very low probability with
>   > impossible". If it absolutely, positively can't take any hit, then
>   > some more work is involved.
>
>   > James Lux, P.E.
>
>   How do you do that? Any web links to study?
Do what? Drive the rates really, really low? There's a whole literature of failure tolerance where you trade off probability of failure in a box against how many boxes against failures in the voting mechanism, etc.  Then, there's the whole class of algorithms pertaining to the "Byzantine Generals Problem" (unreliable, uncooperative actors communicating by unreliable links)
>
>   As far  as I know, it is impossible to absolutely  guarantee against
>   metastability. Do you wait a week for the metastability to settle?
>
>   If zero probability of failure is so important, you would  also have
>   to include  the  probability of a solder joint  opening,  or  a chip
>   failing due  to metal migration or latent ESD damage. That  is never
>   zero.

Indeed.. That's what the whole shake and bake and egregious margin testing is all about for flight hardware. You hope that the testing will find the latent defects. If you're sending it to Jupiter, you don't get a chance to get it back for repair.  And, when you're only building one unit, all the statistics in the world saying that it's a 1E-6 or 1E-12 chance of failure doesn't necessarily give the folks at the launch readiness review a warm fuzzy feeling. So they obssess.. "just in case".. And it still doesn't always work right (Galileo High Gain Antenna, Mars Observer Orbit insertion, Mars Polar Lander entry/descent/landing, etc.)



>
>   Of course, after the system is perfect, someone will take it and put
>   it on a destroyer running Windows:)

Or send you data in pounds when you expect (and the interface document says) Newtons, or you get a solar flare at just the wrong time..

Stuff happens..


From hmurray at megapathdsl.net  Thu Oct 16 23:18:01 2008
From: hmurray at megapathdsl.net (Hal Murray)
Date: Thu, 16 Oct 2008 16:18:01 -0700
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
In-Reply-To: Message from "John Miles" <jmiles@pop.net> of "Thu,
	16 Oct 2008 14:27:20 PDT."
	<PKEGJHPHLLBACEOICCBJGEAAMOAB.jmiles@pop.net> 
Message-ID: <20081016231802.8992FBCD4@ip-64-139-1-69.sjc.megapath.net>


> Well, no, proper domain synchronization doesn't just give you an
> incremental advantage.  The use of flip-flops between clock domains is
> done to trade latency for guaranteed stability.  The idea is to
> isolate the effects of metastability to a single clock edge that won't
> be used to clock anything else.  Unless a metastable event somehow
> lasts more than one clock period (or half-period) it won't constitute
> a failure... and that never happens in practice, in the absence of a
> hard failure.  Correct?  Or am I missing something?  (e.g., are we
> talking cosmic-ray hits, which are much more likely to affect RAM
> elements than clock synchronizers?) 

It can happen.  There is no guarantee.  In a good design, it won't happen 
often enough to be interesting.  Not all designs are good.

The key parameter is settling time.  That's the time between the actual cycle 
time and the cycle time that the design rules (setup/hold, clock-to-out, prop 
delays, clock skew...) would let you run at if you weren't concerned about 
metastability.

Cutting corners like using the other edge of the clock without checking the 
numbers is a good way to get a not-good design.  It doesn't help that the 
manufacturers don't normally provide the data.

For example, if the design rules say your FF to FF path will run at 5ns (200 
MHz) but you are running at 10 ns (100 MHz) you have 5ns of settling time.  
If you use the other edge (and the clock is a clean 50% duty cycle), the 
design rule checkers won't complain, but now you have 0 settling time.

In the old TTL/DIP days, blindly using 2 FFs was a good rule of thumb.  The 
typical state machine had a ROM or ALU or cloud of gates in the timing path.  
The overall cycle time included enough time for their prop delays.  The 
settling time on the FF-FF path (which didn't have any slow parts) was the 
prop delay of the slowest ROM/ALU/whatever.  In practice, that was good 
enough.  (Note that things scale with technology, but might get exciting if 
you mix technologies.)



-- 
These are my opinions, not necessarily my employer's.  I hate spam.





From james.p.lux at jpl.nasa.gov  Thu Oct 16 23:20:50 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Thu, 16 Oct 2008 16:20:50 -0700
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
In-Reply-To: <20081016224013.24B75BCD4@ip-64-139-1-69.sjc.megapath.net>
References: Message from SAIDJACK@aol.com 	of "Thu, 16 Oct 2008 15:21:29
	EDT." <bc0.42895af3.3628ee39@aol.com>
	<20081016224013.24B75BCD4@ip-64-139-1-69.sjc.megapath.net>
Message-ID: <ECE7A93BD093E1439C20020FBE87C47FEB523ED2E6@ALTPHYEMBEVSP20.RES.AD.JPL>

>
> > If it absolutely, positively can't take any hit, then some
> more work
> > is involved
>
> I would say that the first step is to put a number on
> "absolutely, positively".
>
>

There are lots of systems where you can't put a real number on it, for one reason or another.  Either there's too many unknowns, there are political forces at work (viz "put your management hat on"), or the system is so complex that any computed failure probability will approach 1.0, over any reasonable time scale.



> If you aren't willing to take some risk, you won't get off
> the drawing board.
>

That's certainly true, but a lot of times, you can't (or won't) quantify the risk.


So then, you fall back on fuzzy things like "really good" or "really really good" or "whatever we can do for X dollars and Y years with the best people we can hire"

Jim


From XDE-L2G3 at myamail.com  Fri Oct 17 00:05:46 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Thu, 16 Oct 2008 20:05:46 -0400
Subject: [time-nuts] Fwd: Re:  Frequency Stability of Trimble Mini-T
References: <20081017120541.x20q9o4cusscs0os@webmail.has.org.nz>
Message-ID: <mailman.0.1224203704.2533.time-nuts@febo.com>

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From SAIDJACK at aol.com  Thu Oct 16 23:57:11 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Thu, 16 Oct 2008 19:57:11 EDT
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
Message-ID: <cb4.4432ea98.36292ed7@aol.com>


Hi Hal,
 
>First, we understand metastability.  We can measure it and  predict it.  It 
it 
>mattered, we could test each  individual part.
 
That was exactly my original point. The discussion got off topic, I  just 
wanted to point out that it is a matter of probability, and the math to  
calculate this probability of failure is well known and understood.
 
The math says that you cannot prevent a metastable event, even if  there are 
1000 flip flops. The probability is never zero. And since the  processes are 
stochastic, the first failure could happen within 2 seconds of  power on, even 
with 10000, or a million cascaded flip flops. You can never  prevent a 
metastable event going through all of the flops. You can just make  that probability 
approach zero. Actually, if you had a million cascaded flip  flops one of them 
would probably fail due to other reliability reasons  :)
 
>Second, the failure mode is exponential in a parameter we can  control.  So 
>given a particular set of parts to pick  from, it's reasonable to make a 
>design with a probability  of error small enough so that other things are 
much 
>more  important.
 
Right! My original point again. The question was: how often do  crystal jumps 
happen. How often do metastable events happen. Both may be just a  matter of 
statistics and probability.
 
If we don't see a crystal jump within say one month of operation, we  can 
probably say the probability of one happening is extremely low.
 
But I have seen jumps happen after 3 months of continuous, documented  
operation without any jumps, so again we may never have certainty that  
jumps/metastable events will not happen. We just have to make them happen so  seldomly 
that they won't matter to the application at hand. But again if it  jumps after 3 
months, no one can guarantee it won't jump after 10  minutes.
 
bye,
Said



  
____________________________________
 From: SAIDJACK
To: SAIDJACK
Sent: 10/16/2008 16:43:33 Pacific Daylight  Time
Subj: Fwd: [time-nuts] Frequency Stability of Trimble Mini-T





From bogus@does.not.exist.com  Fri Oct 17 00:35:05 2008
From: bogus@does.not.exist.com ()
Date: Fri, 17 Oct 2008 00:35:05 -0000
Subject: No subject
Message-ID: <mailman.1.1224203715.2533.time-nuts@febo.com>

Begin forwarded message:



From: Hal Murray <_hmurray at megapathdsl.net_ (mailto:hmurray at megapathdsl.net) >
Date:  October 16, 2008 15:40:12 PDT
To: Discussion of precise time and  frequency measurement 
<_time-nuts at febo.com_ (mailto:time-nuts at febo.com) >
Subject:  Re: [time-nuts] Frequency Stability of Trimble  Mini-T
Reply-To: Discussion of precise time and frequency  measurement 
<_time-nuts at febo.com_ (mailto:time-nuts at febo.com) >







We have done some extensive research trying  to correlate jumps to


external phenomena (radiation, vibration,  thermal effects, etc).


There is no straight forward  correlation.



It's similar to asynchronous switching  inside a digital computer.


You can add levels of flip flops to  synchronize across two


asynchronous time-domains,  ...


I think that's  misleading in two ways.

First, we  understand metastability.  We can measure it and predict it.  It  
it 
mattered, we could test each individual  part.

Second, the failure mode is  exponential in a parameter we can control.  So 
given a  particular set of parts to pick from, it's reasonable to make a  
design with a probability of error small enough so that  other things are 
much 
more  important.



If it absolutely, positively can't take any  hit, then some more work is  
involved


I would say that the  first step is to put a number on "absolutely,  
positively".

If you aren't  willing to take some risk, you won't get off the drawing  
board.



--  
These are my opinions, not necessarily my employer's.  I hate  spam.




_______________________________________________
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To  unsubscribe, go to 
_https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts_ (https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts) 
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=




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From saidjack at aol.com  Fri Oct 17 00:35:18 2008
From: saidjack at aol.com (Said Jackson)
Date: Thu, 16 Oct 2008 17:35:18 -0700
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
In-Reply-To: <000701c92fc6$7276ace0$0500a8c0@pc52>
References: <bc0.42895af3.3628ee39@aol.com>
	<000701c92fc6$7276ace0$0500a8c0@pc52>
Message-ID: <2E291F4B-CCF3-4D66-AE04-634999E0F8A0@aol.com>

Hi Tom,
Would love to see the efc chart on the mini-t when a jump occurs. That  
would give a definate result...
Said

 From iPhone

On Oct 16, 2008, at 12:36, "Tom Van Baak" <tvb at LeapSecond.com> wrote:

>> I can't find much fundamental research on this at all; and if even  
>> Mr. Vig
>> says the phenomenon is not well understood.. But there are  
>> (propriatary) ways
>> to  probe for the susceptibility of a particular unit to do this.
>
> John told me once that an easy way to deal with many classes
> of jumps is simply use a pair of OCXO. This is an easy solution
> for a time-nut (driven by interest and passion), perhaps much
> less so for a manufacturer (driven by market and profit).
>
> If we as a group find that unpredictable phase or frequency
> jumps are limiting GPSDO performance then that would be a
> fun group discussion on how best to implement a N-way XO
> GPSDO. If done to the extreme it could also reduce phase
> noise as a by-product.
>
> But let's not jump (!) to conclusions that Mike's problem is
> necessarily all quartz related. Given how little testing any of
> us have done on this particular GPSDO, speculation should
> take a back seat to measurement.
>
> /tvb
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.


From XDE-L2G3 at myamail.com  Fri Oct 17 00:58:07 2008
From: XDE-L2G3 at myamail.com (Mike Monett)
Date: Thu, 16 Oct 2008 20:58:07 -0400
Subject: [time-nuts] [Fwd: Re: What is the best counter for a Time Nuts?]
References: <20081014084059.xd9m9xezb4w880s4@webmail.has.org.nz>
	<E1KpaHY-0003Vj-Uw@meow.febo.com>
	<20081014165845.rtpvg7c28cwwk4oc@webmail.has.org.nz>
Message-ID: <mailman.0.1224205168.2536.time-nuts@febo.com>

  >> hasweb at has.org.nz wrote:

  >> There is a 3575A manual for downloading at the Agilent ftp link.

  >> If you read it you will find that the specified error  with 10MHz
  >> inputs is much larger: 10-20 degrees or so.

  The calculation I gave is an upper bound on the stability. It relies
  on the  resolution.  The accuracy is basically  irrelevant  for this
  measurement. Once  the rate of change exceeds about 1/10  degree per
  second, it is impractical to record the data manually, and  you have
  to go to a different method.

  [...]

  >> The basic  principle is sound. It should be very easy  to  make a
  >> simple PWM  circuit  to measure phase  accurately  at  10MHz. You
  >> mentioned the  same thing earlier. Why not post the  schematic so
  >> we can take a look?

  >> Mike Monett

  >Mike

  > I did some time ago, for some examples (other  implementations are
  > also possible) see:

  > http://www.ko4bb.com/~bruce/LinearPhaseComparators.html

  Those are  all  variations  of an XOR.  This  is  perhaps  the worst
  possible phase  detector to use for precision  applications.  It has
  very high ripple at lock, which generates unwanted sidebands  in the
  PLL oscillator output.

  It requires  signals  90 degrees out of phase, so  you  have  to add
  extra logic to lock to signals that are in phase. This adds jitter.

  The output is not referenced to ground, but to some  floating level.
  This means very small offsets and drift will change the lock point.

  It is  also unsuitable for measuring phase angle. The  slope  of the
  transfer curve for the basic XOR reverses at +/- 90 degrees.  So you
  can't use it to measure phase angle.

  The AD9901  hase  all  the above problems but it  rails  at  +/- 180
  degrees instead. It cannot be used to measure phase angle either.

  The standard phase/frequency detector (PFD) is better  for precision
  PLL's since  the output signal is zero at lock.  This  means minimum
  ripple to generate sidebands. It can be reset to a known state so it
  can be  started  in  phase with  an  incoming  signal.  This greatly
  reduces the lock time.

  It wraps  at 360 degrees, so it is also better suited  for measuring
  phase angle.

  These are only some of the issues in analyzing a phase  detector for
  a precision  pll.  Here is a quickie  LTspice  analysis  showing the
  phase detector transfer curves for the three detectors. I  posted it
  so people would not get their mailbox clogged with attachments.

  http://silversol.net63.net/spice/phasedet/phasedet.htm

  [...]

  > The quickest and easiest is to use the AD9901 phase detector as it
  > only has  a few ns of non linearity at the end of  the  range. For
  > higher resolution just add a sigma delta ADC.

  The AD9901  is a very bad design. Probably the poorest  I  have ever
  seen. It  is  unsuitable for measuring phase  angle.  Adding  a high
  resolution ADC will do nothing to help.

  I notice  there is very little in the way of analysis on  your site.
  This means it is impossible to distinguish one circuit from another.

  What you  really  need  to do is go through  and  put  everything in
  LTspice so people can look at the circuit behavior in detail.

  Then you need to do a tolerance and sensitivity analysis to show how
  stable the circuits are over long periods.

  Then you  need to do a noise analysis to show why some  circuits are
  better than others.

  This would make your information much more valuable and interesting.

  One of my big problems right now is trying to understand why the XOR
  works so well in one of the GPSDO's in Tom's Allan variance pages. I
  can't find it at the moment, but I need to take a very close look at
  this design and see what is going on.

  [...]

  >Bruce

  Best Regards,

  Mike Monett


From javier.serrano.pareja at gmail.com  Fri Oct 17 12:55:29 2008
From: javier.serrano.pareja at gmail.com (Javier Serrano)
Date: Fri, 17 Oct 2008 14:55:29 +0200
Subject: [time-nuts] Question on Tom's ADEV plots
Message-ID: <83e48fa10810170555o6487ae39n4978a264d229ba57@mail.gmail.com>

Yes, I am wondering what sort of reference would be ten times better than a
good OCXO at tau=0.1 second and stay good to tau=10^4 seconds. I am looking
at the very first plot of http://www.leapsecond.com/pages/fury/. Also, what
do you mean by " to avoid having to subtract background noise from the ADEV
plot"? Is there a standard recipe for this type of operation?
Thanks again,
Javier

On Fri, Oct 17, 2008 at 11:17 AM, Tom Van Baak <tvb at leapsecond.com> wrote:

>   Hi Tom,
>> I've been looking at some ADEV plots in your website, like
>> the ones for the Fury, and I was wondering if there is a page
>> in the site that explains your measurement setup. I am
>> specifically interested in the reference oscillator you use. It
>> should in principle be much better than the Fury's OCXO for
>> short tau and better than GPS for medium tau, right?
>> Thanks,
>> Javier
>> PS. Feel free to answer to the list. I was not sure I should post
>> this since it's a direct question to you.
>>
>
> Javier,
>
> That's a good question and it sort of depends on which year I
> made the measurement or what performance level I'm expecting
> out of the unit being tested.
>
> I also found out the hard way that it also depends on the tau,
> since different references have different "sweet spots". Now
> that I have quite a range of oscillators here, from BVA to ULN,
> from cesium to maser, I can usually pick one that will give the
> most accurate ADEV or PN plot for the range of tau that I'm
> interested in. Not surprisingly I have no one standard that has
> both the best PN and the best ADEV. For a lot of work I use
> an unlocked Z3801A as the PN ref and a cesium or a locked
> 58503B as the ADEV ref. But it varies according to need or
> what's not in use at the moment.
>
> There's a good chance for any given plot that I have a record
> here of which instrument generated the plot and what reference
> was used. If it's important, either I mention it, or just ask me.
>
> On your GPSDO question, yes, to avoid having to subtract
> background noise from the ADEV plot, one needs to use a
> reference (and measurement system) that is several times,
> maybe even 10x, better than what's being tested.
>
> /tvb
> http://www.LeapSecond.com <http://www.leapsecond.com/>
>
>
>

From tvb at LeapSecond.com  Fri Oct 17 14:40:58 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Fri, 17 Oct 2008 07:40:58 -0700
Subject: [time-nuts] Question on Tom's ADEV plots
References: <83e48fa10810170555o6487ae39n4978a264d229ba57@mail.gmail.com>
Message-ID: <000801c93066$628fabb0$0500a8c0@pc52>

> Yes, I am wondering what sort of reference would be ten times better than a
> good OCXO at tau=0.1 second and stay good to tau=10^4 seconds. I am looking
> at the very first plot of http://www.leapsecond.com/pages/fury/. Also, what
> do you mean by " to avoid having to subtract background noise from the ADEV
> plot"? Is there a standard recipe for this type of operation?
> Thanks again,
> Javier

One short answer is that what is better than a *good* OCXO is
a *better* OCXO. Many FTS 1000- or 1200- series oscillators,
old Sulzers, an HP106, etc. can have performance well down
into the -13's. BVA if you can afford, or borrow one. Once in
a while you'll find a 10811 that's in that range too. When you
do you hang onto it and it becomes your reference, until you
run across one even better, and so on. Or, you use a maser
which gets you in the -14's and -15's.

To get Allan deviation you need to take phase readings between
the UUT oscillator and the reference with something like a time
interval counter. You get your readings, do the math, make a plot
and think you're done. But here's the thing -- these numbers are
not absolute.

Every ADEV point is a measure of the *relative* stability among
the UUT and the reference, and the TIC itself. So not only can
any one of the three components limit the resolution of the plot
at a given tau, but all ADEV points are the rms sum of all three
components. If you know the actual stability for a given tau of
the TIC or the reference you can, with some level of confidence,
rms subtract that known value from the point before it is plotted.

As a simple example, if you know your TIC is not the limiting
factor and you measure the stability of the UUT and a similar
reference to be, say 7e-12, then it could be that both are really
5e-12 (since 5^2 + 5^2 ~= 7^2), which is sqrt(2) better.

Not sure this is a recipe, but you should have the idea by now.

/tvb




From hmurray at megapathdsl.net  Fri Oct 17 17:33:06 2008
From: hmurray at megapathdsl.net (Hal Murray)
Date: Fri, 17 Oct 2008 10:33:06 -0700
Subject: [time-nuts] Fwd: Re: Frequency Stability of Trimble Mini-T
In-Reply-To: Message from hasweb@has.org.nz of "Fri,
	17 Oct 2008 12:05:41 +1300."
	<20081017120541.x20q9o4cusscs0os@webmail.has.org.nz> 
Message-ID: <20081017173307.C2595BCD4@ip-64-139-1-69.sjc.megapath.net>

> You could always look at: United States Patent US4820939.
> But dont bet on it.

I'd go so far as to suggest betting against it.

Back in the 80s when word about metastability was reaching trade rags and 
real designers, I went to a trade show that had a panel on it.  One guy got 
it totally wrong.  1 or 2 mumbled and didn't contribute much.  The only guy 
who got it right was John Wakerly from Stanford.  (Of course, maybe I drunk 
his cool-aid and not theirs.)

Back in those days, there was a lot of activity in designing kludgey circuits 
to "fix" metastability.  I could usually find the flaw.  It got boring after 
a while.  The classic was a circuit to detect metastability and reset the FF. 
That reset signal would sometimes have runt pulses.

There are several problems with such kludges.  First is that they don't work. 
 Second is that they usually make things worse by adding logic in the 
critical path thus reducing the settling time.  On top of that, they are 
usually a pain to analyze.  (If the designer analyzed them correctly, he 
would have thrown it out.)

It's much better to keep the circuit simple.  Then you have a chance of 
correctly estimating the MTTF.

The key is settling time.


The best analog of metastability that I know of is rolling a ball over a 
speed bump.  If the ball is slow, it bounces back.  If the ball is fast, it 
goes up and over.  If the speed is just right, the ball gets to the top of 
the bump and stalls.  If you have a frictionless bump and such, the ball will 
eventually fall off one side or the other.  (You can't adjust the speed to 
the exact value.)

Johnson and Graham's book on Black Magic has a good section on metastability. 
 I think there are some good scope pictures, but my copy isn't handy.

I used to use metastability as a calibration on logic design books.  If I 
couldn't find metastability or synchronizer in the index I didn't expect 
much.  If I did find something, I would scan that section.  A lot of them 
weren't very good.



-- 
These are my opinions, not necessarily my employer's.  I hate spam.





From msokolov at ivan.Harhan.ORG  Fri Oct 17 17:38:48 2008
From: msokolov at ivan.Harhan.ORG (Michael Sokolov)
Date: Fri, 17 Oct 2008 17:38:48 GMT
Subject: [time-nuts] Fwd: Re: Frequency Stability of Trimble Mini-T
Message-ID: <0810171738.AA00278@ivan.Harhan.ORG>

Hal Murray <hmurray at megapathdsl.net> wrote:

> The only guy who got it right was John Wakerly from Stanford.

Yay, the author of my favourite book on digital design!

MS


From swithrow at idcomm.com  Fri Oct 17 18:02:12 2008
From: swithrow at idcomm.com (Skip Withrow)
Date: Fri, 17 Oct 2008 12:02:12 -0600
Subject: [time-nuts] Austron 2100 Loran-C Frequency and Timing Receiver
Message-ID: <20081017180213.36B28B5E3BF@mailhost.idcomm.com>


Hello Time-Nuts, 

Well, my Austron 2100 seems to have bit the dust.  The indication of trouble 
is that the 1pps light quit blinking.  After some debug it appears that all 
the hardware is working (I have the manual with schematics) and that it is 
not getting a software pulse that diddles a flip-flop. 

There are some software diagnostic routines in the box.  The RAM test runs 
fine, but it appears that I get an error on the EPROM test.  The test 
generates an E-20 error.  The book states that if the EPROM test fails it 
will give an E-21, but nowhere do I find any hint as to what an E-20 error 
is. 

I suspect that perhaps I have a corrupted EPROM.  Most of the code appears 
to be working properly (front panel display and buttons work, it will even 
lock to Loran).  There are three 2732A EPROMS, but no indication as to the 
checksum on the devices so can't verify if one is bad. 

Is there a time-nut out there with an Austron 2100?  I would like to get a 
copy of the EPROMS or the code in them to check my unit.  Even the checksums 
would help (given that the firmware revision is the same).  The boards are 
very easily accessed from the front panel and the unit doesn't even have to 
be taken out of the rack.  I have the capability to read and program the 
devices. 

Thanks in advance for any help with this oldie, but (was) goodie. 

Skip Withrow 




From phk at phk.freebsd.dk  Fri Oct 17 18:07:31 2008
From: phk at phk.freebsd.dk (Poul-Henning Kamp)
Date: Fri, 17 Oct 2008 18:07:31 +0000
Subject: [time-nuts] Austron 2100 Loran-C Frequency and Timing Receiver
In-Reply-To: Your message of "Fri, 17 Oct 2008 12:02:12 CST."
	<20081017180213.36B28B5E3BF@mailhost.idcomm.com> 
Message-ID: <41523.1224266851@critter.freebsd.dk>

In message <20081017180213.36B28B5E3BF at mailhost.idcomm.com>, "Skip Withrow" wri
tes:

>Is there a time-nut out there with an Austron 2100?  I would like to get a 
>copy of the EPROMS or the code in them to check my unit.  

I have an 2100F, but that would loose you functionality I guess...

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.


From brooke at pacific.net  Fri Oct 17 18:14:34 2008
From: brooke at pacific.net (Brooke Clarke)
Date: Fri, 17 Oct 2008 11:14:34 -0700
Subject: [time-nuts] Austron 2100 Loran-C Frequency and Timing Receiver
In-Reply-To: <20081017180213.36B28B5E3BF@mailhost.idcomm.com>
References: <20081017180213.36B28B5E3BF@mailhost.idcomm.com>
Message-ID: <48F8D60A.30202@pacific.net>

Hi Skip:

I used the HP signature analyzer and found a bad data bus buffer chip is short 
order.  I'm  sure it would also identify a bad EPROM chip.

Have Fun,

Brooke Clarke
http://www.prc68.com/P/Prod.html  Products I make and sell
http://www.prc68.com/Alpha.shtml  All my web pages listed based on html name
http://www.PRC68.com
http://www.precisionclock.com
http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Web Cam

Skip Withrow wrote:
> Hello Time-Nuts, 
> 
> Well, my Austron 2100 seems to have bit the dust.  The indication of trouble 
> is that the 1pps light quit blinking.  After some debug it appears that all 
> the hardware is working (I have the manual with schematics) and that it is 
> not getting a software pulse that diddles a flip-flop. 
> 
> There are some software diagnostic routines in the box.  The RAM test runs 
> fine, but it appears that I get an error on the EPROM test.  The test 
> generates an E-20 error.  The book states that if the EPROM test fails it 
> will give an E-21, but nowhere do I find any hint as to what an E-20 error 
> is. 
> 
> I suspect that perhaps I have a corrupted EPROM.  Most of the code appears 
> to be working properly (front panel display and buttons work, it will even 
> lock to Loran).  There are three 2732A EPROMS, but no indication as to the 
> checksum on the devices so can't verify if one is bad. 
> 
> Is there a time-nut out there with an Austron 2100?  I would like to get a 
> copy of the EPROMS or the code in them to check my unit.  Even the checksums 
> would help (given that the firmware revision is the same).  The boards are 
> very easily accessed from the front panel and the unit doesn't even have to 
> be taken out of the rack.  I have the capability to read and program the 
> devices. 
> 
> Thanks in advance for any help with this oldie, but (was) goodie. 
> 
> Skip Withrow 
> 
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 


From sar10538 at gmail.com  Fri Oct 17 18:30:14 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Sat, 18 Oct 2008 07:30:14 +1300
Subject: [time-nuts] [Fwd: Re: What is the best counter for a Time Nuts?]
In-Reply-To: <E1Kqdgg-0000gs-1G@meow.febo.com>
References: <20081014084059.xd9m9xezb4w880s4@webmail.has.org.nz>
	<E1KpaHY-0003Vj-Uw@meow.febo.com>
	<20081014165845.rtpvg7c28cwwk4oc@webmail.has.org.nz>
	<E1Kqdgg-0000gs-1G@meow.febo.com>
Message-ID: <1231b6a80810171130s5fc1eac5j3c3067af5cf2a46b@mail.gmail.com>

2008/10/17 Mike Monett <XDE-L2G3 at myamail.com>:

>  Those are  all  variations  of an XOR.  This  is  perhaps  the worst
>  possible phase  detector to use for precision  applications.  It has
>  very high ripple at lock, which generates unwanted sidebands  in the
>  PLL oscillator output.
>
>  It requires  signals  90 degrees out of phase, so  you  have  to add
>  extra logic to lock to signals that are in phase. This adds jitter.
>
>  The output is not referenced to ground, but to some  floating level.
>  This means very small offsets and drift will change the lock point.
>
>  It is  also unsuitable for measuring phase angle. The  slope  of the
>  transfer curve for the basic XOR reverses at +/- 90 degrees.  So you
>  can't use it to measure phase angle.
>
>  The AD9901  hase  all  the above problems but it  rails  at  +/- 180
>  degrees instead. It cannot be used to measure phase angle either.
>
>  The standard phase/frequency detector (PFD) is better  for precision
>  PLL's since  the output signal is zero at lock.  This  means minimum
>  ripple to generate sidebands. It can be reset to a known state so it
>  can be  started  in  phase with  an  incoming  signal.  This greatly
>  reduces the lock time.
>
>  It wraps  at 360 degrees, so it is also better suited  for measuring
>  phase angle.
>
>  These are only some of the issues in analyzing a phase  detector for
>  a precision  pll.  Here is a quickie  LTspice  analysis  showing the
>  phase detector transfer curves for the three detectors. I  posted it
>  so people would not get their mailbox clogged with attachments.
>
>  http://silversol.net63.net/spice/phasedet/phasedet.htm
>
>  [...]
>
>  > The quickest and easiest is to use the AD9901 phase detector as it
>  > only has  a few ns of non linearity at the end of  the  range. For
>  > higher resolution just add a sigma delta ADC.
>
>  The AD9901  is a very bad design. Probably the poorest  I  have ever
>  seen. It  is  unsuitable for measuring phase  angle.  Adding  a high
>  resolution ADC will do nothing to help.
>
>  I notice  there is very little in the way of analysis on  your site.
>  This means it is impossible to distinguish one circuit from another.
>
>  What you  really  need  to do is go through  and  put  everything in
>  LTspice so people can look at the circuit behavior in detail.
>
>  Then you need to do a tolerance and sensitivity analysis to show how
>  stable the circuits are over long periods.
>
>  Then you  need to do a noise analysis to show why some  circuits are
>  better than others.
>
>  This would make your information much more valuable and interesting.
>
>  One of my big problems right now is trying to understand why the XOR
>  works so well in one of the GPSDO's in Tom's Allan variance pages. I
>  can't find it at the moment, but I need to take a very close look at
>  this design and see what is going on.

One of the greatest problems in any pll circuit is instability caused
by time delays in the feedback low pass circuit. In a locked system
where the feedback voltage approaches the rails, stability improves
due to the lower error signal. Getting the time constant of a simple
low pass feedback circuit right is not easy especially in high
precision phase locked systems. Ideally the filter should have a very
low frequency cutoff but have very low time delay and the two are
usually at odds with each other in simple designs.

73
Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From danrae at verizon.net  Fri Oct 17 18:56:30 2008
From: danrae at verizon.net (Dan Rae)
Date: Fri, 17 Oct 2008 11:56:30 -0700
Subject: [time-nuts] Austron 2100 Loran-C Frequency and Timing Receiver
In-Reply-To: <20081017180213.36B28B5E3BF@mailhost.idcomm.com>
References: <20081017180213.36B28B5E3BF@mailhost.idcomm.com>
Message-ID: <48F8DFDE.9020209@verizon.net>

Skip Withrow wrote:
> Well, my Austron 2100 seems to have bit the dust. 
>   
snip
> There are some software diagnostic routines in the box.  The RAM test runs 
> fine, but it appears that I get an error on the EPROM test.  The test 
> generates an E-20 error.  The book states that if the EPROM test fails it 
> will give an E-21, but nowhere do I find any hint as to what an E-20 error 
> is. 

Skip, according to my manual, and I quote directly:  "An output of 
"E-20" indicates a properly functioning EPROM. An output of "E-21" 
indicates that one or more of the EPROMS are bad."

Page 6-12

As to why they bother to have an 'error' message for a good eprom, well, 
there you have got me.  

The next time I have a chance I can certainly get into mine and read the 
EPROMS, but I suspect your trouble lies elsewhere.

My experience with older microprocessors in radios at any rate, is that 
if an EPROM dies, then you will not be able to run any test routines 
anyway :^(

Dan

ac6ao / g3ncr



From scmcgrath at gmail.com  Fri Oct 17 20:41:26 2008
From: scmcgrath at gmail.com (Scott McGrath)
Date: Fri, 17 Oct 2008 16:41:26 -0400
Subject: [time-nuts] Austron 2100 Loran-C Frequency and Timing Receiver
In-Reply-To: <48F8D60A.30202@pacific.net>
References: <20081017180213.36B28B5E3BF@mailhost.idcomm.com>
	<48F8D60A.30202@pacific.net>
Message-ID: <c9ffea950810171341h75706c31la254543cc3b16b59@mail.gmail.com>

I have a 2100 I'll see if my EPROM programmer still works and try and
download the EPROMS to a .HEX file and If I can do that i'll send them
along to Didier and Brooke so they can be hosted for posterity.

- Scott

P.S.

Does anyone have the part number for the 24V cannon connector on the 2100



On Fri, Oct 17, 2008 at 2:14 PM, Brooke Clarke <brooke at pacific.net> wrote:
> Hi Skip:
>
> I used the HP signature analyzer and found a bad data bus buffer chip is short
> order.  I'm  sure it would also identify a bad EPROM chip.
>
> Have Fun,
>
> Brooke Clarke
> http://www.prc68.com/P/Prod.html  Products I make and sell
> http://www.prc68.com/Alpha.shtml  All my web pages listed based on html name
> http://www.PRC68.com
> http://www.precisionclock.com
> http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Web Cam
>
> Skip Withrow wrote:
>> Hello Time-Nuts,
>>
>> Well, my Austron 2100 seems to have bit the dust.  The indication of trouble
>> is that the 1pps light quit blinking.  After some debug it appears that all
>> the hardware is working (I have the manual with schematics) and that it is
>> not getting a software pulse that diddles a flip-flop.
>>
>> There are some software diagnostic routines in the box.  The RAM test runs
>> fine, but it appears that I get an error on the EPROM test.  The test
>> generates an E-20 error.  The book states that if the EPROM test fails it
>> will give an E-21, but nowhere do I find any hint as to what an E-20 error
>> is.
>>
>> I suspect that perhaps I have a corrupted EPROM.  Most of the code appears
>> to be working properly (front panel display and buttons work, it will even
>> lock to Loran).  There are three 2732A EPROMS, but no indication as to the
>> checksum on the devices so can't verify if one is bad.
>>
>> Is there a time-nut out there with an Austron 2100?  I would like to get a
>> copy of the EPROMS or the code in them to check my unit.  Even the checksums
>> would help (given that the firmware revision is the same).  The boards are
>> very easily accessed from the front panel and the unit doesn't even have to
>> be taken out of the rack.  I have the capability to read and program the
>> devices.
>>
>> Thanks in advance for any help with this oldie, but (was) goodie.
>>
>> Skip Withrow
>>
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>


From phk at phk.freebsd.dk  Fri Oct 17 21:33:27 2008
From: phk at phk.freebsd.dk (Poul-Henning Kamp)
Date: Fri, 17 Oct 2008 21:33:27 +0000
Subject: [time-nuts] Austron 2100 Loran-C Frequency and Timing Receiver
In-Reply-To: Your message of "Fri, 17 Oct 2008 11:56:30 MST."
	<48F8DFDE.9020209@verizon.net> 
Message-ID: <99623.1224279207@critter.freebsd.dk>

In message <48F8DFDE.9020209 at verizon.net>, Dan Rae writes:
>Skip Withrow wrote:
>> Well, my Austron 2100 seems to have bit the dust. 
>>   
>snip
>> There are some software diagnostic routines in the box.  The RAM test runs 
>> fine, but it appears that I get an error on the EPROM test.  The test 
>> generates an E-20 error.  The book states that if the EPROM test fails it 
>> will give an E-21, but nowhere do I find any hint as to what an E-20 error 
>> is. 
>
>Skip, according to my manual, and I quote directly:  "An output of 
>"E-20" indicates a properly functioning EPROM. An output of "E-21" 
>indicates that one or more of the EPROMS are bad."
>
>Page 6-12
>
>As to why they bother to have an 'error' message for a good eprom, well, 
>there you have got me.  

Because if you didn't, you still couldn't be sure if the EPROMS worked
well enough to run the test.


-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.


From phk at phk.freebsd.dk  Fri Oct 17 21:34:12 2008
From: phk at phk.freebsd.dk (Poul-Henning Kamp)
Date: Fri, 17 Oct 2008 21:34:12 +0000
Subject: [time-nuts] Austron 2100 Loran-C Frequency and Timing Receiver
In-Reply-To: Your message of "Fri, 17 Oct 2008 16:41:26 -0400."
	<c9ffea950810171341h75706c31la254543cc3b16b59@mail.gmail.com> 
Message-ID: <99634.1224279252@critter.freebsd.dk>

In message <c9ffea950810171341h75706c31la254543cc3b16b59 at mail.gmail.com>, "Scot
t McGrath" writes:

>I have a 2100 I'll see if my EPROM programmer still works and try and
>download the EPROMS to a .HEX file and If I can do that i'll send them
>along to Didier and Brooke so they can be hosted for posterity.

Actually, does anybody know if the only difference between 2100 and 2100F
is the eproms and a couple of connectors on the back ?

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.


From rdarlington at gmail.com  Fri Oct 17 22:47:06 2008
From: rdarlington at gmail.com (Robert Darlington)
Date: Fri, 17 Oct 2008 16:47:06 -0600
Subject: [time-nuts] problem with Efratom FRS-C from eBay
Message-ID: <b3bd5fcb0810171547p4e5c9c57n8a2a5d47e66f4db5@mail.gmail.com>

Hello all,

My FRS-C showed up today.  I carefully wired it up and powered it on.  I got
a nearly 10MHz signal out.  The frequency counter is dancing around a bit
and I get a 0.02 V on the lock indicator line after about an hour warm up.
Specs show this should happen in under 10 minutes and it looks like it is
not locking.   Dead unit?

I obtained it from this ad:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290262243079

The unit that I received does not show TTL after the frequency and the scope
output looks like a cross between a sinewave and a ringing square wave.  I
have about 13 feet of RG174 between the FRS and the measurement equipment so
who knows.   This is the "*Rubidium and GPS DO From
China<http://stores.ebay.com/Rubidium-and-GPS-DO-From-China>"
*eBay store, which I thought was pretty reputable so I want to make sure I'm
not doing anything wrong before I contact the seller, PayPal, etc.*  *There
was also a big white sticker covering the whole top of the unit.  I had to
remove it to verify the pinouts and the model information.  Hoepfully that
didn't void my warranty on the $100 paperweight.  Should I let it sit
overnight?  Any suggestions would greatly be appreciated.

Thanks,
Bob, N3XKB

From namichie at gmail.com  Fri Oct 17 23:07:30 2008
From: namichie at gmail.com (Neville Michie)
Date: Sat, 18 Oct 2008 10:07:30 +1100
Subject: [time-nuts] problem with Efratom FRS-C from eBay
In-Reply-To: <b3bd5fcb0810171547p4e5c9c57n8a2a5d47e66f4db5@mail.gmail.com>
References: <b3bd5fcb0810171547p4e5c9c57n8a2a5d47e66f4db5@mail.gmail.com>
Message-ID: <9D743BEA-A6AD-439C-8C81-1E7E3482FB08@gmail.com>

Hi,
I have bought from this seller before, no problems.
Another seller from china sold me a LPRO which turned out to be  
intermittent,
would run for a few hours then wobble around for a bit, he replaced  
the unit with no
quibbling. Both sellers gave the cheapest deals.
Just check out the feedback other buyers have given them, they depend  
on high
feedback scores and will do the right thing to maintain them.
Just in case you wanted to know,
cheers, Neville Michie


On 18/10/2008, at 9:47 AM, Robert Darlington wrote:

> Hello all,
>
> My FRS-C showed up today.  I carefully wired it up and powered it  
> on.  I got
> a nearly 10MHz signal out.  The frequency counter is dancing around  
> a bit
> and I get a 0.02 V on the lock indicator line after about an hour  
> warm up.
> Specs show this should happen in under 10 minutes and it looks like  
> it is
> not locking.   Dead unit?
>
> I obtained it from this ad:
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290262243079
>
> The unit that I received does not show TTL after the frequency and  
> the scope
> output looks like a cross between a sinewave and a ringing square  
> wave.  I
> have about 13 feet of RG174 between the FRS and the measurement  
> equipment so
> who knows.   This is the "*Rubidium and GPS DO From
> China<http://stores.ebay.com/Rubidium-and-GPS-DO-From-China>"
> *eBay store, which I thought was pretty reputable so I want to make  
> sure I'm
> not doing anything wrong before I contact the seller, PayPal,  
> etc.*  *There
> was also a big white sticker covering the whole top of the unit.  I  
> had to
> remove it to verify the pinouts and the model information.   
> Hoepfully that
> didn't void my warranty on the $100 paperweight.  Should I let it sit
> overnight?  Any suggestions would greatly be appreciated.
>
> Thanks,
> Bob, N3XKB
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ 
> time-nuts
> and follow the instructions there.



From SAIDJACK at aol.com  Fri Oct 17 23:09:33 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Fri, 17 Oct 2008 19:09:33 EDT
Subject: [time-nuts] problem with Efratom FRS-C from eBay
Message-ID: <d2b.399b6485.362a752d@aol.com>

Hi Bob,
 
sorry to hear that. Their feedback seems to be great, so if you discuss the  
problem with them, I would think they will likely help you out with a return  
etc.
 
My question: I was told by people in-the-know that Rubidium Atomic  Frequency 
references are illegal to export to China, and folks have gone to jail  for 
sending these to China.
 
In particular, anything space qualified is not to be exported there, I  think 
the US govt. does not want China to build their own GNSS.
 
See for example page 252:
 
   _http://www.abanet.org/buslaw/newsletter/0041/materials/book.pdf_ 
(http://www.abanet.org/buslaw/newsletter/0041/materials/book.pdf) 
 
Does anyone know if this restriction has been lifted? If not, I wonder how  
they got access to so many Rb's.
 
thanks,
Said
 
 
In a message dated 10/17/2008 15:49:38 Pacific Daylight Time,  
rdarlington at gmail.com writes:

I  obtained it from this  ad:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290262243079

The  unit that I received does not show TTL after the frequency and the  scope
output looks like a cross between a sinewave and a ringing square  wave.  I
have about 13 feet of RG174 between the FRS and the  measurement equipment so
who knows.   This is the "*Rubidium and  GPS DO  From
China<http://stores.ebay.com/Rubidium-and-GPS-DO-From-China>"
*eBay  store, which I thought was pretty reputable so I want to make sure I'm
not  doing anything wrong before I contact the seller, PayPal, etc.*   *There
was also a big white sticker covering the whole top of the  unit.  I had to


From shoppa at trailing-edge.com  Fri Oct 17 23:14:46 2008
From: shoppa at trailing-edge.com (Tim Shoppa)
Date: Fri, 17 Oct 2008 19:14:46 -0400
Subject: [time-nuts] problem with Efratom FRS-C from eBay
In-Reply-To: <d2b.399b6485.362a752d@aol.com>
References: <d2b.399b6485.362a752d@aol.com>
Message-ID: <20081017231446.EF501BA4D0D@mini-me.trailing-edge.com>

SAIDJACK at aol.com wrote:
> My question: I was told by people in-the-know that Rubidium Atomic  Frequency 
> references are illegal to export to China, and folks have gone to jail  for 
> sending these to China.

I am guessing that whatever shows up in that store, has been
removed from surplus telco equipment that got sent to China as
part of reclamation.

> Does anyone know if this restriction has been lifted? If not, I wonder how  
> they got access to so many Rb's.

But they're the ones selling them to us :-). I'm guessing that new
Rubidium standards are made up of 98% Chinese parts, if not 100%.

Sort of like when Feynman was at Los Alamos, he found a hole in the fence,
and used it sneak out and then come in through the official guarded
entrance 5 times in the same hour. As near as they could tell, there
wasn't any rule about coming in without leaving first!

Modern nuclear plant security is actually very picky about this and
they don't let you come in twice without leaving in between.

Tim.


From rdarlington at gmail.com  Fri Oct 17 23:24:01 2008
From: rdarlington at gmail.com (Robert Darlington)
Date: Fri, 17 Oct 2008 17:24:01 -0600
Subject: [time-nuts] problem with Efratom FRS-C from eBay
In-Reply-To: <20081017231446.EF501BA4D0D@mini-me.trailing-edge.com>
References: <d2b.399b6485.362a752d@aol.com>
	<20081017231446.EF501BA4D0D@mini-me.trailing-edge.com>
Message-ID: <b3bd5fcb0810171624q345ed6a1r4d69b127b3048e7c@mail.gmail.com>

For the record, security at this place hasn't improved much since then.  In
three years working there I was never stopped a single time, no matter how
many hard drives or computers I carried in and out of buildings and between
sides of the security fence. I heard about ONE guy that got searched and
they blamed it on his red badge (foreign national, in this case from
Canada).  Heads rolled over that one.  National security is nowhere near as
important to that place as is being politically correct.

Anyway, thanks for the suggestions.  I don't know how I can return this if
it falls under ITAR or other export control regulations.  We'll see.

-Bob ( in Los Alamos!)

On Fri, Oct 17, 2008 at 5:14 PM, Tim Shoppa <shoppa at trailing-edge.com>wrote:

> SAIDJACK at aol.com wrote:
> > My question: I was told by people in-the-know that Rubidium Atomic
>  Frequency
> > references are illegal to export to China, and folks have gone to jail
>  for
> > sending these to China.
>
> I am guessing that whatever shows up in that store, has been
> removed from surplus telco equipment that got sent to China as
> part of reclamation.
>
> > Does anyone know if this restriction has been lifted? If not, I wonder
> how
> > they got access to so many Rb's.
>
> But they're the ones selling them to us :-). I'm guessing that new
> Rubidium standards are made up of 98% Chinese parts, if not 100%.
>
> Sort of like when Feynman was at Los Alamos, he found a hole in the fence,
> and used it sneak out and then come in through the official guarded
> entrance 5 times in the same hour. As near as they could tell, there
> wasn't any rule about coming in without leaving first!
>
> Modern nuclear plant security is actually very picky about this and
> they don't let you come in twice without leaving in between.
>
> Tim.
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

From hmurray at megapathdsl.net  Fri Oct 17 23:24:46 2008
From: hmurray at megapathdsl.net (Hal Murray)
Date: Fri, 17 Oct 2008 16:24:46 -0700
Subject: [time-nuts] problem with Efratom FRS-C from eBay
In-Reply-To: Message from "Robert Darlington" <rdarlington@gmail.com> of "Fri,
	17 Oct 2008 16:47:06 MDT."
	<b3bd5fcb0810171547p4e5c9c57n8a2a5d47e66f4db5@mail.gmail.com> 
Message-ID: <20081017232447.58783BCD4@ip-64-139-1-69.sjc.megapath.net>


> The unit that I received does not show TTL after the frequency and the
> scope output looks like a cross between a sinewave and a ringing
> square wave.  I have about 13 feet of RG174 between the FRS and the
> measurement equipment so who knows.

Do you have a terminator at the far end of the coax?

What does it look like with a scope directly at the unit without any coax?




-- 
These are my opinions, not necessarily my employer's.  I hate spam.





From hasweb at has.org.nz  Fri Oct 17 23:25:56 2008
From: hasweb at has.org.nz (hasweb at has.org.nz)
Date: Sat, 18 Oct 2008 12:25:56 +1300
Subject: [time-nuts] problem with Efratom FRS-C from eBay
In-Reply-To: <b3bd5fcb0810171547p4e5c9c57n8a2a5d47e66f4db5@mail.gmail.com>
References: <b3bd5fcb0810171547p4e5c9c57n8a2a5d47e66f4db5@mail.gmail.com>
Message-ID: <20081018122556.4dymjuwevoc00oo4@webmail.has.org.nz>

Quoting Robert Darlington <rdarlington at gmail.com>:

> Hello all,
>
> My FRS-C showed up today.  I carefully wired it up and powered it on.  I got
> a nearly 10MHz signal out.  The frequency counter is dancing around a bit
> and I get a 0.02 V on the lock indicator line after about an hour warm up.
> Specs show this should happen in under 10 minutes and it looks like it is
> not locking.   Dead unit?
>
> I obtained it from this ad:
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290262243079
>
> The unit that I received does not show TTL after the frequency and the scope
> output looks like a cross between a sinewave and a ringing square wave.  I
> have about 13 feet of RG174 between the FRS and the measurement equipment so
> who knows.   This is the "*Rubidium and GPS DO From
> China<http://stores.ebay.com/Rubidium-and-GPS-DO-From-China>"
> *eBay store, which I thought was pretty reputable so I want to make sure I'm
> not doing anything wrong before I contact the seller, PayPal, etc.*  *There
> was also a big white sticker covering the whole top of the unit.  I had to
> remove it to verify the pinouts and the model information.  Hoepfully that
> didn't void my warranty on the $100 paperweight.  Should I let it sit
> overnight?  Any suggestions would greatly be appreciated.
>
> Thanks,
> Bob, N3XKB
Bob

What was the terminating impeadnce at the end of the 13 ft of RG174?
Can you post a picture of the waveform?

Bruce



From SAIDJACK at aol.com  Fri Oct 17 23:48:04 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Fri, 17 Oct 2008 19:48:04 EDT
Subject: [time-nuts] problem with Efratom FRS-C from eBay
Message-ID: <cc7.424956ce.362a7e34@aol.com>

Thanks for the feedback guys.
 
It makes sense, I guess old out-of-service equipment is being sent to China  
for recycling, that must be how they get these Rb's. I wonder if the 
regulations  have been relaxed about Rb's though.
 
Symmetricom got busted on this sort of thing some time ago:
 
   _https://www.bis.doc.gov/news/2004/symmetriconoct04.htm_ 
(https://www.bis.doc.gov/news/2004/symmetriconoct04.htm) 
 
bye,
Said
 
 
In a message dated 10/17/2008 16:27:25 Pacific Daylight Time,  
rdarlington at gmail.com writes:

Anyway,  thanks for the suggestions.  I don't know how I can return this if
it  falls under ITAR or other export control regulations.  We'll  see.

-Bob ( in Los  Alamos!)



From james.p.lux at jpl.nasa.gov  Fri Oct 17 23:50:50 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Fri, 17 Oct 2008 16:50:50 -0700
Subject: [time-nuts] problem with Efratom FRS-C from eBay
In-Reply-To: <20081017231446.EF501BA4D0D@mini-me.trailing-edge.com>
References: <d2b.399b6485.362a752d@aol.com>
	<20081017231446.EF501BA4D0D@mini-me.trailing-edge.com>
Message-ID: <ECE7A93BD093E1439C20020FBE87C47FEB523ED379@ALTPHYEMBEVSP20.RES.AD.JPL>


> -----Original Message-----
> From: time-nuts-bounces at febo.com
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Tim Shoppa
> Sent: Friday, October 17, 2008 4:15 PM
> To: time-nuts at febo.com
> Subject: Re: [time-nuts] problem with Efratom FRS-C from eBay
>
> SAIDJACK at aol.com wrote:
> > My question: I was told by people in-the-know that Rubidium Atomic
> > Frequency references are illegal to export to China, and folks have
> > gone to jail  for sending these to China.

There you go, as an engineer or scientist, expecting interpretation of export regulations to be consistent and make sense. They aren't and they don't. Unless it's on a list of clearly permitted exports, each case gets decided individually, and there's plenty of "or similar technology" kinds of clauses in the ITAR and munitions list.
Heck, there's two different agencies involved (Dept of State for ITAR and Dept of Commerce for EAR) and they could make separate and different determinations.


The EAR has:
3A002  General purpose electronic equipment, as follows (see List
of Items Controlled).
G Atomic frequency standards having any of the following:
    g.1. Long-term stability (aging) less (better) than 1E-11/month; or
    g.2. Being ``space qualified''.

    Note: 3A002.g.1 does not control non-``space qualified''
rubidium standards.


The MCTL has (for space qualified clocks)
>15yr service life on orbit
>12 yr life on orbit, in dormant state
<1E-15/day long term stability


From cdelect at juno.com  Sat Oct 18 00:24:56 2008
From: cdelect at juno.com (Corby Dawson)
Date: Fri, 17 Oct 2008 17:24:56 -0700
Subject: [time-nuts] FRSC problem
Message-ID: <20081017.172456.3204.5.cdelect@juno.com>


Bob,

Use a 50 ohm termination on the counters input and use a 1 second gate
time.

Power up from a cold start (off at least 1/2 hour) and watch the
frequency or the control voltage. The frequency should vary about 50 hz
or more as the control voltage sweeps about 15 volts. As it warms up it
should start sweeping across the center frequency of 10Mhz. If it stops
sweeping after 8 or so minutes it is most likely locking.
Depending on how the lock pin is configured it could be open collector
(useing a DVM on the ohms semiconductor position with the + lead on the
lock pin and the other to ground, will read open until locked and then
read a low value when locked.) or it could be wired to give a TTL level
output when locked. Lamp voltage shopuld be > 8VDC. Hope this helps.

Corby Dawson
____________________________________________________________
Click here for free information on nursing degrees, up to $150/hour
http://thirdpartyoffers.juno.com/TGL2141/fc/Ioyw6i3nEnlcpvqS5yN8Pn4HQn1rAgSMADmL8Phsl5T7J0H4fUn3TD/


From ed_palmer at sasktel.net  Sat Oct 18 00:55:52 2008
From: ed_palmer at sasktel.net (Ed Palmer)
Date: Fri, 17 Oct 2008 18:55:52 -0600
Subject: [time-nuts] problem with Efratom FRS-C from eBay
In-Reply-To: <mailman.22.1224285891.2539.time-nuts@febo.com>
References: <mailman.22.1224285891.2539.time-nuts@febo.com>
Message-ID: <48F93418.7030300@sasktel.net>

Three things you can check are:

1.  How close to 10 MHz?  I bought an FRK-L a while back that wouldn't 
lock.  I was able to watch the frequency sweep up and down as it tried 
to find the Rb frequency.  The sweep takes about 40 sec. to complete a 
cycle.  It turned out that the xtal had aged to the point that it wasn't 
even getting up to the right frequency and the coarse tuning adjustment 
didn't have enough range.  A quick change of the value of an internal 
tuning capacitor fixed it right up.  You need to have about 8 or 9 
digits on your counter to see the sweeping.

2.  What's happening to the crystal monitor voltage?  Similar to the 
above, you should be able to see it rise and fall as the system tries to 
find the Rb signal.

Normally, this kind of sweeping action means that the Rb signal is weak 
or dead.  So.....

3.  What's the lamp monitor voltage?  The FRS-C should be >= 6V.  My 
FRK-L is spec'ed at >= 7V.  Mine locks down to about 5.4V.

Ed

> Hello all,
>
> My FRS-C showed up today.  I carefully wired it up and powered it on.  I got
> a nearly 10MHz signal out.  The frequency counter is dancing around a bit
> and I get a 0.02 V on the lock indicator line after about an hour warm up.
> Specs show this should happen in under 10 minutes and it looks like it is
> not locking.   Dead unit?
>
> I obtained it from this ad:
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290262243079
>
> The unit that I received does not show TTL after the frequency and the scope
> output looks like a cross between a sinewave and a ringing square wave.  I
> have about 13 feet of RG174 between the FRS and the measurement equipment so
> who knows.   This is the "*Rubidium and GPS DO From
> China<http://stores.ebay.com/Rubidium-and-GPS-DO-From-China>"
> *eBay store, which I thought was pretty reputable so I want to make sure I'm
> not doing anything wrong before I contact the seller, PayPal, etc.*  *There
> was also a big white sticker covering the whole top of the unit.  I had to
> remove it to verify the pinouts and the model information.  Hoepfully that
> didn't void my warranty on the $100 paperweight.  Should I let it sit
> overnight?  Any suggestions would greatly be appreciated.
>
> Thanks,
> Bob, N3XKB
>   



From rdarlington at gmail.com  Sat Oct 18 00:59:09 2008
From: rdarlington at gmail.com (Robert Darlington)
Date: Fri, 17 Oct 2008 18:59:09 -0600
Subject: [time-nuts] problem with Efratom FRS-C from eBay
In-Reply-To: <20081017232447.58783BCD4@ip-64-139-1-69.sjc.megapath.net>
References: <rdarlington@gmail.com>
	<b3bd5fcb0810171547p4e5c9c57n8a2a5d47e66f4db5@mail.gmail.com>
	<20081017232447.58783BCD4@ip-64-139-1-69.sjc.megapath.net>
Message-ID: <b3bd5fcb0810171759q55d491efx82fea950c9d29a64@mail.gmail.com>

Okay, my first mistake here was not having a terminator when looking at it
on the scope, but it was terminated at 50ohms when attached to the counter.
This looks much nicer:

http://www.nerdhouse.org/frsc.jpg

Turning off the 20MHz bandwidth filter cleaned it up to what you see
there.   When I gate the frequency counter with the 1PPS signal from the
Lassen iQ, I'm getting 10,000,000 +/- 1Hz counts. This seems reasonable, as
that fits the spec of the counter (HP 5335A).  When counting using the
internal TCXO which may be way off, I'm getting 9,999,975.55 Hz +/- 0.06Hz
give or take).

When I first powered it on I did see the frequency swing to either side of
10MHz and settle down a bit, then settle down some more.  The last digit
moves a bit, sometimes moving the one before it (0.xx Hz).  Maybe this thing
IS working and is measuring the stability of the oscillator in the counter.
I still see nothing on the lock line but it may need a pull up resistor.
I'll play around with it some more.  I'm getting dragged to dinner so I
can't play anymore tonight.

Thank you all for the help and suggestions.  I'm very green but am learning.

-Bob

On Fri, Oct 17, 2008 at 5:24 PM, Hal Murray <hmurray at megapathdsl.net> wrote:

>
> > The unit that I received does not show TTL after the frequency and the
> > scope output looks like a cross between a sinewave and a ringing
> > square wave.  I have about 13 feet of RG174 between the FRS and the
> > measurement equipment so who knows.
>
> Do you have a terminator at the far end of the coax?
>
> What does it look like with a scope directly at the unit without any coax?
>
>
>
>
> --
> These are my opinions, not necessarily my employer's.  I hate spam.
>
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

From smace at intt.net  Sat Oct 18 01:09:05 2008
From: smace at intt.net (Scott Mace)
Date: Fri, 17 Oct 2008 20:09:05 -0500
Subject: [time-nuts] problem with Efratom FRS-C from eBay
In-Reply-To: <b3bd5fcb0810171547p4e5c9c57n8a2a5d47e66f4db5@mail.gmail.com>
References: <b3bd5fcb0810171547p4e5c9c57n8a2a5d47e66f4db5@mail.gmail.com>
Message-ID: <48F93731.9010001@intt.net>

I have a FRS-A which is very similar to your unit, but with a LPRO compatible
pin-out.  This came out of a Lucent RFTG box.  It would take a long time to power
up, and I found that the power supply was no good.  I removed the unit and kept
it on a piece of the chassis as a heatsink and used a new 24v switcher.
This unit still takes longer than the 10min to lock, but once it locks it's solid.
The lock indication goes low when locked, high when unlocked.  It has a strong 10mhz
TTL output.  You should attach some sort of heatsink to the baseplate.  The FRS-A
runs hotter than any of the LPRO units I have.  I've had good luck with the
Datum labeled LPRO-101 units.  What are you using the measure the frequency?
Sounds like your unit is locking if the BITE is low.  The usual thing that
kills these units isn't the lamp itself but noise from some other source in
the physics package.

I've purchased from this seller several times before and he replaced a bad
LPRO unit (powered up and locked for 1 hour then unlocked and never locked
again).  Usually, it is not practical to repair these units as most of the parts
cannot be swapped from unit to unit without changing some undocumented adjustments.

	Scott


Robert Darlington wrote:
> Hello all,
> 
> My FRS-C showed up today.  I carefully wired it up and powered it on.  I got
> a nearly 10MHz signal out.  The frequency counter is dancing around a bit
> and I get a 0.02 V on the lock indicator line after about an hour warm up.
> Specs show this should happen in under 10 minutes and it looks like it is
> not locking.   Dead unit?
> 
> I obtained it from this ad:
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290262243079
> 
> The unit that I received does not show TTL after the frequency and the scope
> output looks like a cross between a sinewave and a ringing square wave.  I
> have about 13 feet of RG174 between the FRS and the measurement equipment so
> who knows.   This is the "*Rubidium and GPS DO From
> China<http://stores.ebay.com/Rubidium-and-GPS-DO-From-China>"
> *eBay store, which I thought was pretty reputable so I want to make sure I'm
> not doing anything wrong before I contact the seller, PayPal, etc.*  *There
> was also a big white sticker covering the whole top of the unit.  I had to
> remove it to verify the pinouts and the model information.  Hoepfully that
> didn't void my warranty on the $100 paperweight.  Should I let it sit
> overnight?  Any suggestions would greatly be appreciated.
> 
> Thanks,
> Bob, N3XKB
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 
> 


From cfharris at erols.com  Sat Oct 18 03:04:13 2008
From: cfharris at erols.com (Chuck Harris)
Date: Fri, 17 Oct 2008 23:04:13 -0400
Subject: [time-nuts] Austron 2100 Loran-C Frequency and Timing Receiver
In-Reply-To: <99634.1224279252@critter.freebsd.dk>
References: <99634.1224279252@critter.freebsd.dk>
Message-ID: <48F9522D.3060608@erols.com>

The difference is much greater than that.  The 2100F has a large
number of chips that aren't populated, that are in the 2100T.  Also,
the 2100T has its front end filters graded for delay times.  There
are a few more buttons on the front panel of the 2100T than are on
the 2100F.

The CPU board, and the 488 board are the same.  I seem to recall the
ROMS are the same too.

-Chuck Harris

Poul-Henning Kamp wrote:
> In message <c9ffea950810171341h75706c31la254543cc3b16b59 at mail.gmail.com>, "Scot
> t McGrath" writes:
> 
>> I have a 2100 I'll see if my EPROM programmer still works and try and
>> download the EPROMS to a .HEX file and If I can do that i'll send them
>> along to Didier and Brooke so they can be hosted for posterity.
> 
> Actually, does anybody know if the only difference between 2100 and 2100F
> is the eproms and a couple of connectors on the back ?
> 


From rdarlington at gmail.com  Sat Oct 18 03:40:35 2008
From: rdarlington at gmail.com (Robert Darlington)
Date: Fri, 17 Oct 2008 21:40:35 -0600
Subject: [time-nuts] problem with Efratom FRS-C from eBay
In-Reply-To: <b3bd5fcb0810171547p4e5c9c57n8a2a5d47e66f4db5@mail.gmail.com>
References: <b3bd5fcb0810171547p4e5c9c57n8a2a5d47e66f4db5@mail.gmail.com>
Message-ID: <b3bd5fcb0810172040l23c95694y9b9249de6e1603b@mail.gmail.com>

I got it, it's working (and it always was).   Reading the manual I see that
the lock signal can either be high or low depending on how some jumpers are
set on the servo board.  I unplugged the supply, disconnected the connector,
and added proper lines to my meter while the unit cooled off a bit and
rested.  A few minutes later with everything connected I plugged it in.  5
volts out of the lock line was present while the system hunted.  A couple of
minutes later and the frequency counter stabilized and the meter went to
0.02 volts.   The voltage on the lamp monitor is reading 8.78 to 8.79
volts.  Stabilized is relative, and if this thing had more digits, I'd like
to think that I'd have a few more not moving.

Thanks for helping out guys.  I really appreciate it.

On Fri, Oct 17, 2008 at 4:47 PM, Robert Darlington <rdarlington at gmail.com>wrote:

> Hello all,
>
> My FRS-C showed up today.  I carefully wired it up and powered it on.  I
> got a nearly 10MHz signal out.  The frequency counter is dancing around a
> bit and I get a 0.02 V on the lock indicator line after about an hour warm
> up.  Specs show this should happen in under 10 minutes and it looks like it
> is not locking.   Dead unit?
>
> I obtained it from this ad:
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290262243079
>
> The unit that I received does not show TTL after the frequency and the
> scope output looks like a cross between a sinewave and a ringing square
> wave.  I have about 13 feet of RG174 between the FRS and the measurement
> equipment so who knows.   This is the "*Rubidium and GPS DO From China<http://stores.ebay.com/Rubidium-and-GPS-DO-From-China>"
> *eBay store, which I thought was pretty reputable so I want to make sure
> I'm not doing anything wrong before I contact the seller, PayPal, etc.*  *There
> was also a big white sticker covering the whole top of the unit.  I had to
> remove it to verify the pinouts and the model information.  Hoepfully that
> didn't void my warranty on the $100 paperweight.  Should I let it sit
> overnight?  Any suggestions would greatly be appreciated.
>
> Thanks,
> Bob, N3XKB
>

From stephen at blob.demon.co.uk  Sat Oct 18 07:38:13 2008
From: stephen at blob.demon.co.uk (Stephen Tompsett)
Date: Sat, 18 Oct 2008 08:38:13 +0100
Subject: [time-nuts] EFRATOM FRT Manual?
Message-ID: <48F99265.8060108@blob.demon.co.uk>

My local radio Society has recently been donated a couple of EFRATOM FRT 
Rubidium Frequency Standards.

They contain a FRK-H Rubidium Module, and both appear to be working.

I have the documentation for the Rubidium module, but do not have any 
circuit details for the support circuitry

Does anyone have a manual or any further information about these units?

--
Stephen Tompsett



From hmurray at megapathdsl.net  Sun Oct 19 00:59:18 2008
From: hmurray at megapathdsl.net (Hal Murray)
Date: Sat, 18 Oct 2008 17:59:18 -0700
Subject: [time-nuts] Frequency Stability of Trimble Mini-T
In-Reply-To: Message from "Tom Van Baak" <tvb@LeapSecond.com> of "Thu,
	16 Oct 2008 12:36:12 PDT." <000701c92fc6$7276ace0$0500a8c0@pc52> 
Message-ID: <20081019005919.945E4BCD4@ip-64-139-1-69.sjc.megapath.net>


> John told me once that an easy way to deal with many classes of jumps
> is simply use a pair of OCXO. This is an easy solution for a time-nut
> (driven by interest and passion), perhaps much less so for a
> manufacturer (driven by market and profit). 

How do you know which one jumped?  Do they always jump in the same direction?

How do you switch between OCXOs without inserting a glitch?  Or is the short 
term glitch less of a problem than the longer term step?

Is it reasonable to run two OCXOs in lock step?

-- 
These are my opinions, not necessarily my employer's.  I hate spam.





From BriMDavis at aol.com  Sun Oct 19 17:43:49 2008
From: BriMDavis at aol.com (BriMDavis at aol.com)
Date: Sun, 19 Oct 2008 13:43:49 EDT
Subject: [time-nuts] Metastability (was: Frequency Stability of Trimble
	Mini-T)
Message-ID: <c89.37395f5d.362ccbd5@aol.com>

Hal wrote:
>
>Back in those days, there was a lot of activity in designing kludgey 
circuits 
>to "fix" metastability.  I could usually find the flaw.  It got boring after 
>a while.  The classic was a circuit to detect metastability and reset the 
FF. 
>That reset signal would sometimes have runt pulses.
>

My favorite online metastability page:

_http://www.fpga-faq.com/FAQ_Pages/0017_Tell_me_about_metastables.htm_ 
(http://www.fpga-faq.com/FAQ_Pages/0017_Tell_me_about_metastables.htm) 

This page discusses a few of those "fixes" and why they don't work,
along with some pointers to the relevant literature.

There are also some nice real-time scope shots showing
some of the various runt pulses that can occur:
"
"  _http://www.fpga-faq.com/Images/meta_pic_1.jpg_ 
(http://www.fpga-faq.com/Images/meta_pic_1.jpg)  
"  _http://www.fpga-faq.com/Images/meta_pic_2.jpg_ 
(http://www.fpga-faq.com/Images/meta_pic_2.jpg) 
"  _http://www.fpga-faq.com/Images/meta_pic_3.jpg_ 
(http://www.fpga-faq.com/Images/meta_pic_3.jpg) 
"
"These are far from just delayed outputs! The end result though
"is still the same, systems that fail. But seeing these scope
"pictures of the actual Q output might make you think about how
"you measure metastability.
"

Brian
**************BUY Indiana Jones and the Kingdom of the Crystal Skull on DVD 
today! 
(http://pr.atwola.com/promoclk/100000075x1209326865x1200539441/aol?redir=http://www.indianajones.com/site/index.html)


From rexa at sonic.net  Sun Oct 19 22:05:34 2008
From: rexa at sonic.net (Rex)
Date: Sun, 19 Oct 2008 15:05:34 -0700
Subject: [time-nuts] OT- Tbolt eBay -- where in the world...
Message-ID: <48FBAF2E.8010904@sonic.net>

I was looking at one of the Thunderbolt listings on eBay today: 
300260419007

I noticed that there is a picture of a Tbolt Monitor screen with lat and 
lon, so I put it in Google Earth. Seems to show the corner of the 
building where the antenna is mounted, near Shanghai. Attached is a GE 
placemark file. Just thought it was an interesting diversion.

I don't see any parking lots. I wonder how everyone gets to work? Busses?



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From bruce.griffiths at xtra.co.nz  Sun Oct 19 22:48:59 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Mon, 20 Oct 2008 11:48:59 +1300
Subject: [time-nuts] OT- Tbolt eBay -- where in the world...
In-Reply-To: <48FBAF2E.8010904@sonic.net>
References: <48FBAF2E.8010904@sonic.net>
Message-ID: <48FBB95B.2080703@xtra.co.nz>

Rex wrote:
> I was looking at one of the Thunderbolt listings on eBay today: 
> 300260419007
>
> I noticed that there is a picture of a Tbolt Monitor screen with lat 
> and lon, so I put it in Google Earth. Seems to show the corner of the 
> building where the antenna is mounted, near Shanghai. Attached is a GE 
> placemark file. Just thought it was an interesting diversion.
>
> I don't see any parking lots. I wonder how everyone gets to work? Busses?
Perhaps by train or bicycle.

bruce


From bruce.griffiths at xtra.co.nz  Sun Oct 19 22:55:22 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Mon, 20 Oct 2008 11:55:22 +1300
Subject: [time-nuts] OT- Tbolt eBay -- where in the world...
In-Reply-To: <48FBAF2E.8010904@sonic.net>
References: <48FBAF2E.8010904@sonic.net>
Message-ID: <48FBBADA.6010503@xtra.co.nz>

Rex wrote:
> I was looking at one of the Thunderbolt listings on eBay today: 
> 300260419007
>
> I noticed that there is a picture of a Tbolt Monitor screen with lat 
> and lon, so I put it in Google Earth. Seems to show the corner of the 
> building where the antenna is mounted, near Shanghai. Attached is a GE 
> placemark file. Just thought it was an interesting diversion.
>
> I don't see any parking lots. I wonder how everyone gets to work? Busses?
>
How about the Shanghai  Maglev?

bruce


From jim77742 at gmail.com  Mon Oct 20 00:12:57 2008
From: jim77742 at gmail.com (Jim Palfreyman)
Date: Mon, 20 Oct 2008 11:12:57 +1100
Subject: [time-nuts] OT- Tbolt eBay -- where in the world...
In-Reply-To: <48FBAF2E.8010904@sonic.net>
References: <48FBAF2E.8010904@sonic.net>
Message-ID: <f616e0f80810191712y20e873catea047db97f35c6e1@mail.gmail.com>

Rex,

This city is one of the most dense in the world with regard to population.
And maybe it might be hard to imagine for some, but cars are not the main
form of transport.

Read http://en.wikipedia.org/wiki/Shanghai#Transport for a summary.

Regards,

Jim


2008/10/20 Rex <rexa at sonic.net>

> I was looking at one of the Thunderbolt listings on eBay today:
> 300260419007
>
> I noticed that there is a picture of a Tbolt Monitor screen with lat and
> lon, so I put it in Google Earth. Seems to show the corner of the building
> where the antenna is mounted, near Shanghai. Attached is a GE placemark
> file. Just thought it was an interesting diversion.
>
> I don't see any parking lots. I wonder how everyone gets to work? Busses?
>
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

From tvb at LeapSecond.com  Mon Oct 20 01:18:54 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Sun, 19 Oct 2008 18:18:54 -0700
Subject: [time-nuts] Thunderbolt Group Buy, part 3
Message-ID: <000901c93251$d5b071a0$0500a8c0@pc52>

Thunderbolt group buy: MORE kits and NEW price.

Recently, TAPR completed all outstanding orders of Trimble
ThunderBolt GPS receiver + AULT power supply kits. Those
of you who ordered should have received yours by now. Since
the stock of both TBolts and power supplies was limited, some
of you missed the opportunity to place an order or to order
a second unit. Now is your chance.

The good news is that the telecom salvage firm found more
TBolts for us and today TAPR is again accepting orders. In
case you're wondering, these are not coming from China.

The bad news is we can't find a replacement vendor for those
nice AULT power supplies. So we decided to offer this batch
of TBolt's without a power supply (but you still get antenna
and DC connectors, as before).

There's enough information out there on compatible +5 +/-12 V
power supplies that this shouldn't be a big problem (see FAQ).
And it will also reduce costs -- those power supplies had to
ship from Asia to All Electronics to me to TAPR to you.

Group buy description (updated, please read):
http://www.leapsecond.com/pages/tapr-tbolt

TAPR order page (see adjusted price):
http://www.tapr.org/kits_thunder.html

ThunderBolt FAQ:
http://www.leapsecond.com/tbolt-faq.htm

Please email specific questions directly to me rather than
bother the whole time-nuts group.

Thanks,
/tvb
tvb at LeapSecond.com




From rexa at sonic.net  Mon Oct 20 02:50:30 2008
From: rexa at sonic.net (Rex)
Date: Sun, 19 Oct 2008 19:50:30 -0700
Subject: [time-nuts] OT- Tbolt eBay -- where in the world...
In-Reply-To: <48FBBADA.6010503@xtra.co.nz>
References: <48FBAF2E.8010904@sonic.net> <48FBBADA.6010503@xtra.co.nz>
Message-ID: <48FBF1F6.5030200@sonic.net>

Bruce Griffiths wrote:
> Rex wrote:
>   
>> I was looking at one of the Thunderbolt listings on eBay today: 
>> 300260419007
>>
>> I noticed that there is a picture of a Tbolt Monitor screen with lat 
>> and lon, so I put it in Google Earth. Seems to show the corner of the 
>> building where the antenna is mounted, near Shanghai. Attached is a GE 
>> placemark file. Just thought it was an interesting diversion.
>>
>> I don't see any parking lots. I wonder how everyone gets to work? Busses?
>>
>>     
> How about the Shanghai  Maglev?
>
> bruce
>
>
>   

So I looked more. This site seems to be kind of on the outskirts of 
Shanghai. There are some university locations near by.

The maglev track does run very close, but seems it only has two stops, 
the near one over 2 miles away, the far end at the airport to the 
southeast. The closest metro stop seems to be at Zhangjiang Hi-Tech Park 
which is a little over a mile away. Right next to the office park 
hosting the GPS, there is a canal, but I doubt this would be an 
efficient commuter route. The nearest big road is Luoshan Rd which may 
have a bus line, and I assume there is probably some kind of commuter 
connection from the Zhangjiang station.

As I was looking at Google Earth I saw a very large circular structure, 
just across the road, looking in the satellite image like it was under 
construction. I was sure it must be some kind of stadium, except it 
seemed to have a lot of structure where I expected the field should be. 
My first guess was something for the Olympics. Turns out it is a very 
different kind of sport. It is the Shanghai Synchrotron Radiation 
Facility, SSRF.    http://ssrf.sinap.ac.cn/english/   Just starting to 
become functional now.




From SAIDJACK at aol.com  Mon Oct 20 03:41:12 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Sun, 19 Oct 2008 23:41:12 EDT
Subject: [time-nuts] OT- Tbolt eBay -- where in the world...
Message-ID: <d32.41dd2458.362d57d8@aol.com>

Hi Rex,
 
I've been to Shanghai many times. Usual mode of transportation is bike,  
subway, bus or if you can afford it car. Lot's of electric bikes and motorcycles  
too of course.

Since foreigners are usually not allowed to drive you will see loads of  
taxis too.
 
Wonderful city to visit. Like Paris in the 1920's. So much energy, and  
nightlife that no sailor would pass on. Standard of living beyond your wildest  
dreams if you have a couple of 1000's of US Dollars per month. Very open and  
friendly to westerners. Lot's of super-rich folks too.
 
bye,
Said
 
 
In a message dated 10/19/2008 19:51:48 Pacific Daylight Time,  rexa at sonic.net 
writes:


The  maglev track does run very close, but seems it only has two stops, 
the  near one over 2 miles away, the far end at the airport to the 
southeast.  The closest metro stop seems to be at Zhangjiang Hi-Tech Park 
which is a  little over a mile away. Right next to the office park 
hosting the GPS,  there is a canal, but I doubt this would be an 
efficient commuter route.  The nearest big road is Luoshan Rd which may 
have a bus line, and I assume  there is probably some kind of commuter 
connection from the Zhangjiang  station.



From quenbob5 at pacbell.net  Mon Oct 20 04:01:06 2008
From: quenbob5 at pacbell.net (Bob Q)
Date: Sun, 19 Oct 2008 21:01:06 -0700
Subject: [time-nuts] problem with Efratom FRS-C from eBay
References: <b3bd5fcb0810171547p4e5c9c57n8a2a5d47e66f4db5@mail.gmail.com>
	<b3bd5fcb0810172040l23c95694y9b9249de6e1603b@mail.gmail.com>
Message-ID: <001501c93268$7b0ac220$1801a8c0@BOBCEL1R7>

Just a note on my experience with "Rubidium and GPSDO...".  I bought an OCXO 
from him.  I had to set the control voltage to about 70 mV to get 10 MHz 
out, too close to 0V to work in my GPS DO circuit.  The OCXO did not have a 
mechanical adjustment in addition to the electircal adjustment, useful to 
center the range of the electrical adjustment.   I sent an email to the 
seller and he offered to either refund my money or send a replacement unit 
for the cost of postage, without returning the first unit.  The replacement 
unit works fine.
Bob Q.

----- Original Message ----- 
From: "Robert Darlington" <rdarlington at gmail.com>
To: "Discussion of precise time and frequency measurement" 
<time-nuts at febo.com>
Sent: Friday, October 17, 2008 8:40 PM
Subject: Re: [time-nuts] problem with Efratom FRS-C from eBay


>I got it, it's working (and it always was).   Reading the manual I see that
> the lock signal can either be high or low depending on how some jumpers 
> are
> set on the servo board.  I unplugged the supply, disconnected the 
> connector,
> and added proper lines to my meter while the unit cooled off a bit and
> rested.  A few minutes later with everything connected I plugged it in.  5
> volts out of the lock line was present while the system hunted.  A couple 
> of
> minutes later and the frequency counter stabilized and the meter went to
> 0.02 volts.   The voltage on the lamp monitor is reading 8.78 to 8.79
> volts.  Stabilized is relative, and if this thing had more digits, I'd 
> like
> to think that I'd have a few more not moving.
>
> Thanks for helping out guys.  I really appreciate it.
>
> On Fri, Oct 17, 2008 at 4:47 PM, Robert Darlington 
> <rdarlington at gmail.com>wrote:
>
>> Hello all,
>>
>> My FRS-C showed up today.  I carefully wired it up and powered it on.  I
>> got a nearly 10MHz signal out.  The frequency counter is dancing around a
>> bit and I get a 0.02 V on the lock indicator line after about an hour 
>> warm
>> up.  Specs show this should happen in under 10 minutes and it looks like 
>> it
>> is not locking.   Dead unit?
>>
>> I obtained it from this ad:
>> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=290262243079
>>
>> The unit that I received does not show TTL after the frequency and the
>> scope output looks like a cross between a sinewave and a ringing square
>> wave.  I have about 13 feet of RG174 between the FRS and the measurement
>> equipment so who knows.   This is the "*Rubidium and GPS DO From 
>> China<http://stores.ebay.com/Rubidium-and-GPS-DO-From-China>"
>> *eBay store, which I thought was pretty reputable so I want to make sure
>> I'm not doing anything wrong before I contact the seller, PayPal, etc.* 
>> *There
>> was also a big white sticker covering the whole top of the unit.  I had 
>> to
>> remove it to verify the pinouts and the model information.  Hoepfully 
>> that
>> didn't void my warranty on the $100 paperweight.  Should I let it sit
>> overnight?  Any suggestions would greatly be appreciated.
>>
>> Thanks,
>> Bob, N3XKB
>>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there. 



From sar10538 at gmail.com  Mon Oct 20 12:22:31 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Tue, 21 Oct 2008 01:22:31 +1300
Subject: [time-nuts] OT- Tbolt eBay -- where in the world...
In-Reply-To: <d32.41dd2458.362d57d8@aol.com>
References: <d32.41dd2458.362d57d8@aol.com>
Message-ID: <1231b6a80810200522l6e3d742ci362079361dc90dd7@mail.gmail.com>

Hi all,

Just in case anyone was interested in this Google Earth location,
Bob's comment on it was:-

> Your google earth location NOT my home.
> Any how let me show u my home.
> your mark send to me,just from my friend's in ShangHai City,The Biggest City
> In China.
> My home Guangzhou City near HongKong,just 1 hour...by train .My Home
> Guangzhou with the best food in China?Called Guangzhou Cuisine.

Attached is the correct location.

73
Steve

2008/10/20  <SAIDJACK at aol.com>:
> Hi Rex,
>
> I've been to Shanghai many times. Usual mode of transportation is bike,
> subway, bus or if you can afford it car. Lot's of electric bikes and motorcycles
> too of course.
>
> Since foreigners are usually not allowed to drive you will see loads of
> taxis too.
>
> Wonderful city to visit. Like Paris in the 1920's. So much energy, and
> nightlife that no sailor would pass on. Standard of living beyond your wildest
> dreams if you have a couple of 1000's of US Dollars per month. Very open and
> friendly to westerners. Lot's of super-rich folks too.
>
> bye,
> Said
>
>
> In a message dated 10/19/2008 19:51:48 Pacific Daylight Time,  rexa at sonic.net
> writes:
>
>
> The  maglev track does run very close, but seems it only has two stops,
> the  near one over 2 miles away, the far end at the airport to the
> southeast.  The closest metro stop seems to be at Zhangjiang Hi-Tech Park
> which is a  little over a mile away. Right next to the office park
> hosting the GPS,  there is a canal, but I doubt this would be an
> efficient commuter route.  The nearest big road is Luoshan Rd which may
> have a bus line, and I assume  there is probably some kind of commuter
> connection from the Zhangjiang  station.
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>



-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet
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From true-cal at swbell.net  Mon Oct 20 18:05:33 2008
From: true-cal at swbell.net (Don @ True-Cal)
Date: Mon, 20 Oct 2008 11:05:33 -0700 (PDT)
Subject: [time-nuts] Question and help with LPRO-101
Message-ID: <293828.42409.qm@web81807.mail.mud.yahoo.com>

Hello,
?
Can anyone guide me or give me a link to internal settings on the Efratom LPRO-101 Rb oscillator. I have the User's and Integration Guide but I am looking for more detailed information on any optional settings that may be available from the many inside jumpers and/or hidden connectors. Specifically, all of the units I have provide a 10MHz sine wave output and I am wanting a 1PPS output on one of the units. I believe there are LPROs that provide a 1PPS output but not sure if they are a different part number unit with different electronics or just different jumper options inside. I scoped the hidden connector J6 but no 1PPS signal.
?
There is a 9-pair J8 jumper block with 2 jumpers and a 7-pair J8 with one jumper and a 2-pair J1 with no jumper. There is also a connector block J9 and a 3-pair J10 but they are back by the Rb lamp/cavity with analog signals on some probably for initial test/calibration.
?
My units are Cage Code 55761, ?Part Number 102500-001
?
Thanks...
Don

From ian.sheffield1 at tesco.net  Mon Oct 20 18:34:01 2008
From: ian.sheffield1 at tesco.net (Ian Sheffield)
Date: Mon, 20 Oct 2008 19:34:01 +0100
Subject: [time-nuts] Question and help with LPRO-101
References: <293828.42409.qm@web81807.mail.mud.yahoo.com>
Message-ID: <004701c932e2$6d292320$0300000a@cookie>

Hello Don,

Sorry to hijack your question, but how do you get inside an LPRO-101? Does 
the case just spring off?

Thanks,

Ian.


----- Original Message ----- 
From: "Don @ True-Cal" <true-cal at swbell.net>
To: <time-nuts at febo.com>
Sent: Monday, October 20, 2008 7:05 PM
Subject: [time-nuts] Question and help with LPRO-101


Hello,

Can anyone guide me or give me a link to internal settings on the Efratom 
LPRO-101 Rb oscillator. I have the User's and Integration Guide but I am 
looking for more detailed information on any optional settings that may be 
available from the many inside jumpers and/or hidden connectors. 
Specifically, all of the units I have provide a 10MHz sine wave output and I 
am wanting a 1PPS output on one of the units. I believe there are LPROs that 
provide a 1PPS output but not sure if they are a different part number unit 
with different electronics or just different jumper options inside. I scoped 
the hidden connector J6 but no 1PPS signal.

There is a 9-pair J8 jumper block with 2 jumpers and a 7-pair J8 with one 
jumper and a 2-pair J1 with no jumper. There is also a connector block J9 
and a 3-pair J10 but they are back by the Rb lamp/cavity with analog signals 
on some probably for initial test/calibration.

My units are Cage Code 55761, Part Number 102500-001

Thanks...
Don
_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to 
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.


--------------------------------------------------------------------------------



No virus found in this incoming message.
Checked by AVG - http://www.avg.com
Version: 8.0.173 / Virus Database: 270.8.1/1734 - Release Date: 10/20/2008 
07:25



From true-cal at swbell.net  Mon Oct 20 18:57:31 2008
From: true-cal at swbell.net (Don @ True-Cal)
Date: Mon, 20 Oct 2008 11:57:31 -0700 (PDT)
Subject: [time-nuts] Question and help with LPRO-101
Message-ID: <20306.73306.qm@web81808.mail.mud.yahoo.com>

Ian,

No problem, more discussion - the better.

Unscrew?the two hex standoffs on either side on the connector, pull the 10-pin feed-through out of the internal connector. Note the position of the grounded pins vs. the capacitive bypass feedthrough pins.?This will free up the metal cover to "snap" off of the base plate. A very small screwdriver can be used in the small slots at each of the four coners to pry?the box cover free from the base plate.

Caution, here is where a little will-power is needed to resist tuning the several adjustments for "better performance".

Have fun,
Don


----- Original Message ----
From: Ian Sheffield <ian.sheffield1 at tesco.net>
To: Discussion of precise time and frequency measurement <time-nuts at febo.com>
Sent: Monday, October 20, 2008 1:34:01 PM
Subject: Re: [time-nuts] Question and help with LPRO-101

Hello Don,

Sorry to hijack your question, but how do you get inside an LPRO-101? Does 
the case just spring off?

Thanks,

Ian.


----- Original Message ----- 
From: "Don @ True-Cal" <true-cal at swbell.net>
To: <time-nuts at febo.com>
Sent: Monday, October 20, 2008 7:05 PM
Subject: [time-nuts] Question and help with LPRO-101


Hello,

Can anyone guide me or give me a link to internal settings on the Efratom 
LPRO-101 Rb oscillator. I have the User's and Integration Guide but I am 
looking for more detailed information on any optional settings that may be 
available from the many inside jumpers and/or hidden connectors. 
Specifically, all of the units I have provide a 10MHz sine wave output and I 
am wanting a 1PPS output on one of the units. I believe there are LPROs that 
provide a 1PPS output but not sure if they are a different part number unit 
with different electronics or just different jumper options inside. I scoped 
the hidden connector J6 but no 1PPS signal.

There is a 9-pair J8 jumper block with 2 jumpers and a 7-pair J8 with one 
jumper and a 2-pair J1 with no jumper. There is also a connector block J9 
and a 3-pair J10 but they are back by the Rb lamp/cavity with analog signals 
on some probably for initial test/calibration.

My units are Cage Code 55761, Part Number 102500-001

Thanks...
Don
_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to 
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.


--------------------------------------------------------------------------------



No virus found in this incoming message.
Checked by AVG - http://www.avg.com
Version: 8.0.173 / Virus Database: 270.8.1/1734 - Release Date: 10/20/2008 
07:25


_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

From ian.sheffield1 at tesco.net  Mon Oct 20 19:31:56 2008
From: ian.sheffield1 at tesco.net (Ian Sheffield)
Date: Mon, 20 Oct 2008 20:31:56 +0100
Subject: [time-nuts] Question and help with LPRO-101
References: <20306.73306.qm@web81808.mail.mud.yahoo.com>
Message-ID: <008401c932ea$84ac7300$0300000a@cookie>

Many thanks Don,

The only thing I want to look at (and tweek) is the C Field adjustment. For 
some reason I can't seem to be able to turn the pot properly through the 
small hole in the case, so I will have a look to see if anything is 
mechanically mis-aligned.

I promise I won't tweek anything else!

Cheers,

Ian.

----- Original Message ----- 
From: "Don @ True-Cal" <true-cal at swbell.net>
To: "Discussion of precise time and frequency measurement" 
<time-nuts at febo.com>
Sent: Monday, October 20, 2008 7:57 PM
Subject: Re: [time-nuts] Question and help with LPRO-101


Ian,

No problem, more discussion - the better.

Unscrew the two hex standoffs on either side on the connector, pull the 
10-pin feed-through out of the internal connector. Note the position of the 
grounded pins vs. the capacitive bypass feedthrough pins. This will free up 
the metal cover to "snap" off of the base plate. A very small screwdriver 
can be used in the small slots at each of the four coners to pry the box 
cover free from the base plate.

Caution, here is where a little will-power is needed to resist tuning the 
several adjustments for "better performance".

Have fun,
Don


----- Original Message ----
From: Ian Sheffield <ian.sheffield1 at tesco.net>
To: Discussion of precise time and frequency measurement 
<time-nuts at febo.com>
Sent: Monday, October 20, 2008 1:34:01 PM
Subject: Re: [time-nuts] Question and help with LPRO-101

Hello Don,

Sorry to hijack your question, but how do you get inside an LPRO-101? Does
the case just spring off?

Thanks,

Ian.


----- Original Message ----- 
From: "Don @ True-Cal" <true-cal at swbell.net>
To: <time-nuts at febo.com>
Sent: Monday, October 20, 2008 7:05 PM
Subject: [time-nuts] Question and help with LPRO-101


Hello,

Can anyone guide me or give me a link to internal settings on the Efratom
LPRO-101 Rb oscillator. I have the User's and Integration Guide but I am
looking for more detailed information on any optional settings that may be
available from the many inside jumpers and/or hidden connectors.
Specifically, all of the units I have provide a 10MHz sine wave output and I
am wanting a 1PPS output on one of the units. I believe there are LPROs that
provide a 1PPS output but not sure if they are a different part number unit
with different electronics or just different jumper options inside. I scoped
the hidden connector J6 but no 1PPS signal.

There is a 9-pair J8 jumper block with 2 jumpers and a 7-pair J8 with one
jumper and a 2-pair J1 with no jumper. There is also a connector block J9
and a 3-pair J10 but they are back by the Rb lamp/cavity with analog signals
on some probably for initial test/calibration.

My units are Cage Code 55761, Part Number 102500-001

Thanks...
Don
_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.


--------------------------------------------------------------------------------



No virus found in this incoming message.
Checked by AVG - http://www.avg.com
Version: 8.0.173 / Virus Database: 270.8.1/1734 - Release Date: 10/20/2008
07:25


_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to 
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to 
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.


--------------------------------------------------------------------------------



No virus found in this incoming message.
Checked by AVG - http://www.avg.com
Version: 8.0.173 / Virus Database: 270.8.1/1734 - Release Date: 10/20/2008 
07:25



From bruce.tayloriv at gmail.com  Mon Oct 20 20:09:07 2008
From: bruce.tayloriv at gmail.com (Bruce Taylor)
Date: Mon, 20 Oct 2008 16:09:07 -0400
Subject: [time-nuts] Getting NTP/Linux to work with GPS-DO?
Message-ID: <566ce880810201309i2474a188x5340a69a6533bc5e@mail.gmail.com>

Folks,

  Has anyone gotten a Jackson Labs 'Fury' gps-do to work as a time/pps
source for Linux?

  Our lab is looking to use both the stable 10MHz clock for various
LOs on a radio-telescope, and also get reasonably tight timing for a
software correllator to use in discriminating pulsar signals.

  Our Linux guy has lost most of his hair out trying to get the NTP
daemon to receive the PPS signal and thus get NTP to see the GPS-DO as
a stratum 0 source.

  Our configuration is: vanilla Linux from kernel.org (version 2.6.23)
running on an intel platform.  We've applied the LinuxPPS kernel
patch, and we're feeding the serial port with the Fury in NMEA mode.
We made the required internal mod on the Fury to feed the PPS signal
out on the serial port, and can see it blinking using a scope.

  Apologies if my description is vague, as I'm just getting into the
fun and joy of kernel hacking :-)

  Many thanks for any advice,

  - Bruce Taylor


From namichie at gmail.com  Mon Oct 20 20:19:23 2008
From: namichie at gmail.com (Neville Michie)
Date: Tue, 21 Oct 2008 07:19:23 +1100
Subject: [time-nuts] Question and help with LPRO-101
In-Reply-To: <008401c932ea$84ac7300$0300000a@cookie>
References: <20306.73306.qm@web81808.mail.mud.yahoo.com>
	<008401c932ea$84ac7300$0300000a@cookie>
Message-ID: <1BB54D49-DD22-4996-8FA7-82B397C0ED63@gmail.com>

Hi,
a word of caution about opening the LPRO,
the manual says that the case is made of Mu metal.
This alloy has an enormously hi permeability and shields
low level magnetic fields from the rubidium cell.
Back in the 60s when I worked on instrument maintenance
and oscilloscopes had Mu metal shields they warned that the
metal was annealed and lost its properties if it was bent (work hardened
I assume). So just be careful to gently spring the case just enough  
for the pips to
clear the locating holes.
The frequency of operation depends precisely on the magnetic field,
cheers, Neville MIchie



On 21/10/2008, at 6:31 AM, Ian Sheffield wrote:

> Many thanks Don,
>
> The only thing I want to look at (and tweek) is the C Field  
> adjustment. For
> some reason I can't seem to be able to turn the pot properly  
> through the
> small hole in the case, so I will have a look to see if anything is
> mechanically mis-aligned.
>
> I promise I won't tweek anything else!
>
> Cheers,
>
> Ian.
>
> ----- Original Message -----
> From: "Don @ True-Cal" <true-cal at swbell.net>
> To: "Discussion of precise time and frequency measurement"
> <time-nuts at febo.com>
> Sent: Monday, October 20, 2008 7:57 PM
> Subject: Re: [time-nuts] Question and help with LPRO-101
>
>
> Ian,
>
> No problem, more discussion - the better.
>
> Unscrew the two hex standoffs on either side on the connector, pull  
> the
> 10-pin feed-through out of the internal connector. Note the  
> position of the
> grounded pins vs. the capacitive bypass feedthrough pins. This will  
> free up
> the metal cover to "snap" off of the base plate. A very small  
> screwdriver
> can be used in the small slots at each of the four coners to pry  
> the box
> cover free from the base plate.
>
> Caution, here is where a little will-power is needed to resist  
> tuning the
> several adjustments for "better performance".
>
> Have fun,
> Don
>
>
> ----- Original Message ----
> From: Ian Sheffield <ian.sheffield1 at tesco.net>
> To: Discussion of precise time and frequency measurement
> <time-nuts at febo.com>
> Sent: Monday, October 20, 2008 1:34:01 PM
> Subject: Re: [time-nuts] Question and help with LPRO-101
>
> Hello Don,
>
> Sorry to hijack your question, but how do you get inside an  
> LPRO-101? Does
> the case just spring off?
>
> Thanks,
>
> Ian.
>
>
> ----- Original Message -----
> From: "Don @ True-Cal" <true-cal at swbell.net>
> To: <time-nuts at febo.com>
> Sent: Monday, October 20, 2008 7:05 PM
> Subject: [time-nuts] Question and help with LPRO-101
>
>
> Hello,
>
> Can anyone guide me or give me a link to internal settings on the  
> Efratom
> LPRO-101 Rb oscillator. I have the User's and Integration Guide but  
> I am
> looking for more detailed information on any optional settings that  
> may be
> available from the many inside jumpers and/or hidden connectors.
> Specifically, all of the units I have provide a 10MHz sine wave  
> output and I
> am wanting a 1PPS output on one of the units. I believe there are  
> LPROs that
> provide a 1PPS output but not sure if they are a different part  
> number unit
> with different electronics or just different jumper options inside.  
> I scoped
> the hidden connector J6 but no 1PPS signal.
>
> There is a 9-pair J8 jumper block with 2 jumpers and a 7-pair J8  
> with one
> jumper and a 2-pair J1 with no jumper. There is also a connector  
> block J9
> and a 3-pair J10 but they are back by the Rb lamp/cavity with  
> analog signals
> on some probably for initial test/calibration.
>
> My units are Cage Code 55761, Part Number 102500-001
>
> Thanks...
> Don
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>
> ---------------------------------------------------------------------- 
> ----------
>
>
>
> No virus found in this incoming message.
> Checked by AVG - http://www.avg.com
> Version: 8.0.173 / Virus Database: 270.8.1/1734 - Release Date:  
> 10/20/2008
> 07:25
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>
> ---------------------------------------------------------------------- 
> ----------
>
>
>
> No virus found in this incoming message.
> Checked by AVG - http://www.avg.com
> Version: 8.0.173 / Virus Database: 270.8.1/1734 - Release Date:  
> 10/20/2008
> 07:25
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ 
> time-nuts
> and follow the instructions there.



From stanley_reynolds at yahoo.com  Mon Oct 20 20:35:20 2008
From: stanley_reynolds at yahoo.com (Stanley Reynolds)
Date: Mon, 20 Oct 2008 13:35:20 -0700 (PDT)
Subject: [time-nuts] Getting NTP/Linux to work with GPS-DO?
Message-ID: <691073.77855.qm@web30306.mail.mud.yahoo.com>

The two things that come to mind are is the pulse wide enough and is it the correct polarity. Polarity wrong would only add delay but the pulse width would cause the PC to not see it.

Check these?links:

http://www.tapr.org/kits_fatpps.html

http://www.wraith.sf.ca.us/ntp/#gps-receiver


?


----- Original Message ----
From: Bruce Taylor <bruce.tayloriv at gmail.com>
To: time-nuts at febo.com
Sent: Monday, October 20, 2008 3:09:07 PM
Subject: [time-nuts] Getting NTP/Linux to work with GPS-DO?

Folks,

? Has anyone gotten a Jackson Labs 'Fury' gps-do to work as a time/pps
source for Linux?

? Our lab is looking to use both the stable 10MHz clock for various
LOs on a radio-telescope, and also get reasonably tight timing for a
software correllator to use in discriminating pulsar signals.

? Our Linux guy has lost most of his hair out trying to get the NTP
daemon to receive the PPS signal and thus get NTP to see the GPS-DO as
a stratum 0 source.

? Our configuration is: vanilla Linux from kernel.org (version 2.6.23)
running on an intel platform.? We've applied the LinuxPPS kernel
patch, and we're feeding the serial port with the Fury in NMEA mode.
We made the required internal mod on the Fury to feed the PPS signal
out on the serial port, and can see it blinking using a scope.

? Apologies if my description is vague, as I'm just getting into the
fun and joy of kernel hacking :-)

? Many thanks for any advice,

? - Bruce Taylor

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



From bg at lysator.liu.se  Mon Oct 20 20:42:39 2008
From: bg at lysator.liu.se (=?ISO-8859-1?Q?Bj=F6rn?= Gabrielsson)
Date: Mon, 20 Oct 2008 22:42:39 +0200
Subject: [time-nuts] Getting NTP/Linux to work with GPS-DO?
In-Reply-To: <566ce880810201309i2474a188x5340a69a6533bc5e@mail.gmail.com>
References: <566ce880810201309i2474a188x5340a69a6533bc5e@mail.gmail.com>
Message-ID: <1224535359.17353.36.camel@bg-desktop>

Hi Bruce,

On Mon, 2008-10-20 at 16:09 -0400, Bruce Taylor wrote:
> Folks,
> 
>   Has anyone gotten a Jackson Labs 'Fury' gps-do to work as a time/pps
> source for Linux?
> 
>   Our lab is looking to use both the stable 10MHz clock for various
> LOs on a radio-telescope, and also get reasonably tight timing for a
> software correllator to use in discriminating pulsar signals.
> 
>   Our Linux guy has lost most of his hair out trying to get the NTP
> daemon to receive the PPS signal and thus get NTP to see the GPS-DO as
> a stratum 0 source.

Try a 2.4-kernel, see below.

>   Our configuration is: vanilla Linux from kernel.org (version 2.6.23)
> running on an intel platform.  We've applied the LinuxPPS kernel
> patch, and we're feeding the serial port with the Fury in NMEA mode.

LinuxPPS is _very_ much work in progress. You are on the bleeding edge!
I am not sure the dust has settled enough for stable performance.

If your LAB have the option -- and some hair left -- try the latest 2.4
kernel with a working PPSKit-patch.

    http://www.kernel.org/pub/linux/daemons/ntp/PPS/

Do not know if there are later ones than 2.1.7 somewhere else.

I have 2.4.3X-something kernel running on a lab laptop with a standard
NMEA serial stream with PPS on DCD, that converges down to sub 10us
offset within a minute or two. (There might be reasons not to trust the
NTP stats down at this level, but...)

> We made the required internal mod on the Fury to feed the PPS signal
> out on the serial port, and can see it blinking using a scope.

Most serial ports I have tested will tolerate a standard PPS-pulse even
if its voltage levels are (way) noncompliant with RS232. YMMV!


To see if you get the pulses through the serial port, you might run
the radioclkd in test mode.
 
     http://www.buzzard.me.uk/jonathan/downloads/radioclk-1.0.tar.gz

That will show you both edges on signals attached to DCD, CTS or DSR.
This approach could also be used to time your signals from a user space
program.

>   Apologies if my description is vague, as I'm just getting into the
> fun and joy of kernel hacking :-)

Good luck!

>   Many thanks for any advice,
> 
>   - Bruce Taylor
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.



From jra at febo.com  Mon Oct 20 21:26:01 2008
From: jra at febo.com (John Ackermann N8UR)
Date: Mon, 20 Oct 2008 17:26:01 -0400
Subject: [time-nuts] Getting NTP/Linux to work with GPS-DO?
In-Reply-To: <566ce880810201309i2474a188x5340a69a6533bc5e@mail.gmail.com>
References: <566ce880810201309i2474a188x5340a69a6533bc5e@mail.gmail.com>
Message-ID: <48FCF769.3020604@febo.com>

Bruce, unfortunately Linux doesn't play too nicely with PPS -- long
story, but you need to do patches to get even minimal functionality with
current kernels.

An option is to use a shared memory driver called shmpps (available from
http://time.qnan.org/).  I've done this in the past, but had a little
trouble keeping the driver running reliably; it would sometimes die
silently, causing loss of the PPS source.  However, I think I was using
an earlier version than the one that's on that web page.

Using this approach will let you use the PPS signal, but won't give you
coarse time via the serial data stream.  To get that, you can use the HP
driver in ntpd which supports the HP Z3801A/58503A command set.  I think
that the Jackson Fury emulates these commands, though I haven't tried it
with this driver.

But if you can, a FreeBSD system makes a *much* better ntp server.  I am
a Linux guy, but my primary ntp boxes all are slightly modified Soekris
4501A single-board computers running a stripped down FreeBSD.  They run
rings around anything else.

Hope this helps a bit.

John
----

Bruce Taylor said the following on 10/20/2008 04:09 PM:
> Folks,
> 
>   Has anyone gotten a Jackson Labs 'Fury' gps-do to work as a time/pps
> source for Linux?
> 
>   Our lab is looking to use both the stable 10MHz clock for various
> LOs on a radio-telescope, and also get reasonably tight timing for a
> software correllator to use in discriminating pulsar signals.
> 
>   Our Linux guy has lost most of his hair out trying to get the NTP
> daemon to receive the PPS signal and thus get NTP to see the GPS-DO as
> a stratum 0 source.
> 
>   Our configuration is: vanilla Linux from kernel.org (version 2.6.23)
> running on an intel platform.  We've applied the LinuxPPS kernel
> patch, and we're feeding the serial port with the Fury in NMEA mode.
> We made the required internal mod on the Fury to feed the PPS signal
> out on the serial port, and can see it blinking using a scope.
> 
>   Apologies if my description is vague, as I'm just getting into the
> fun and joy of kernel hacking :-)
> 
>   Many thanks for any advice,
> 
>   - Bruce Taylor
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.


From jcline01 at sbcglobal.net  Mon Oct 20 21:28:15 2008
From: jcline01 at sbcglobal.net (Joe Cline)
Date: Mon, 20 Oct 2008 16:28:15 -0500
Subject: [time-nuts] HP 59551A Power Supply Needed
Message-ID: <001201c932fa$c3d74e50$4b85eaf0$@net>

Hi Everyone!

 

I just purchased a HP 59551A GPS Measurements Synchronization Module on
eBay, and I ran into a snag with the power supply. This model is supposed to
have an IEC 320 jack and be able to run on run on 120 VAC or 129 VDC, but it
has only an XLR 3-pin jack with a tag for 129 VDC! I can find no schematic
to verify power requirements. Even if this unit accepts 129 VDC, what is the
current rating, and who makes a simple supply capable of providing the
needed wattage? I could probably put together a homebrew supply, but it
would be nice to design it for the required load.

 

Does anyone have any experience or source for technical information for the
59551A? I appreciate any help you could provide.

 

Thanks,

 

Joe / KN5U


From bruce.griffiths at xtra.co.nz  Mon Oct 20 21:44:42 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Tue, 21 Oct 2008 10:44:42 +1300
Subject: [time-nuts] HP 59551A Power Supply Needed
In-Reply-To: <001201c932fa$c3d74e50$4b85eaf0$@net>
References: <001201c932fa$c3d74e50$4b85eaf0$@net>
Message-ID: <48FCFBCA.5010308@xtra.co.nz>

Joe Cline wrote:
> Hi Everyone!
>
>  
>
> I just purchased a HP 59551A GPS Measurements Synchronization Module on
> eBay, and I ran into a snag with the power supply. This model is supposed to
> have an IEC 320 jack and be able to run on run on 120 VAC or 129 VDC, but it
> has only an XLR 3-pin jack with a tag for 129 VDC! I can find no schematic
> to verify power requirements. Even if this unit accepts 129 VDC, what is the
> current rating, and who makes a simple supply capable of providing the
> needed wattage? I could probably put together a homebrew supply, but it
> would be nice to design it for the required load.
>
>  
>
> Does anyone have any experience or source for technical information for the
> 59551A? I appreciate any help you could provide.
>
>  
>
> Thanks,
>
>  
>
> Joe / KN5U
>   
Joe

Since the 59551A is rated at 50VA with an AC input the dc requirements 
is likely to be of a similar order.
Thus its highly likely that a 129V dc 1A supply is overkill and a supply 
rated at 0.5A may suffice.


Bruce


From smace at intt.net  Mon Oct 20 22:18:00 2008
From: smace at intt.net (Scott Mace)
Date: Mon, 20 Oct 2008 17:18:00 -0500
Subject: [time-nuts] Getting NTP/Linux to work with GPS-DO?
In-Reply-To: <566ce880810201309i2474a188x5340a69a6533bc5e@mail.gmail.com>
References: <566ce880810201309i2474a188x5340a69a6533bc5e@mail.gmail.com>
Message-ID: <48FD0398.1070301@intt.net>

I have it working under FreeBSD w/ a custom ntp refclock.  It does
not work with the hpgps refclock.  PTIME:TCODE is not on-time.
The 1-PPS output is a couple 100ms wide, so there is no need for a
PPS stretcher.  I'm using a soekris net4501 w/ the tmrin mod
that is documented on febo.com.  Attached is a patch
which should work on both linux and freebsd, but for
kernel pps support, you will need to apply one of the various
kernel patches... Older 2.4kernels are better supported.  FreeBSD
has it natively.

Here's a sample ntp.conf

server 127.127.45.0 prefer minpoll 4 maxpoll 4 iburst
fudge 127.127.45.0 time1 0.012 #115200
fudge 127.127.45.0 flag3 1
server 127.127.22.0 minpoll 4 maxpoll 4
tos mindist 0.050

driftfile /media/log/ntpd.drift

statsdir /media/log/
statistics loopstats peerstats clockstats
filegen loopstats file loopstats type day enable
filegen peerstats file peerstats type day enable
filegen clockstats file clockstats type day enable


sysctl.conf

machdep.elan_gpio_config=-----P...--..--------..---------


also I have to modify the sio driver in the kernel:
/sys/dev/sio/sio.c

diff -u sio.c.orig sio.c
--- sio.c.orig  2008-06-27 15:11:52.000000000 -0500
+++ sio.c       2008-10-04 10:32:57.000000000 -0500
@@ -1928,7 +1928,7 @@
          * (about 3 ticks if input flow control is not used or not honoured,
          * but a bit less for CS5-CS7 modes).
          */
-       cp4ticks = speed / 10 / hz * 4;
+       cp4ticks = speed / 10 / hz * 40;
         for (ibufsize = 128; ibufsize < cp4ticks;)
                 ibufsize <<= 1;
         if (ibufsize == com->ibufsize) {





	Scott

Bruce Taylor wrote:
> Folks,
> 
>   Has anyone gotten a Jackson Labs 'Fury' gps-do to work as a time/pps
> source for Linux?
> 
>   Our lab is looking to use both the stable 10MHz clock for various
> LOs on a radio-telescope, and also get reasonably tight timing for a
> software correllator to use in discriminating pulsar signals.
> 
>   Our Linux guy has lost most of his hair out trying to get the NTP
> daemon to receive the PPS signal and thus get NTP to see the GPS-DO as
> a stratum 0 source.
> 
>   Our configuration is: vanilla Linux from kernel.org (version 2.6.23)
> running on an intel platform.  We've applied the LinuxPPS kernel
> patch, and we're feeding the serial port with the Fury in NMEA mode.
> We made the required internal mod on the Fury to feed the PPS signal
> out on the serial port, and can see it blinking using a scope.
> 
>   Apologies if my description is vague, as I'm just getting into the
> fun and joy of kernel hacking :-)
> 
>   Many thanks for any advice,
> 
>   - Bruce Taylor
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 
> 
-------------- next part --------------
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From normn3ykf at stny.rr.com  Tue Oct 21 06:10:08 2008
From: normn3ykf at stny.rr.com (Norman J McSweyn)
Date: Tue, 21 Oct 2008 02:10:08 -0400
Subject: [time-nuts] HP 5335a opt 40 addendum
Message-ID: <48FD7240.1070308@stny.rr.com>

Hi all!
I'm having some trouble programming my 5335a. The manual that Agilent 
has doesn't cover opt 40. Have psyched out several of the codes that 
aren't in the manual.
Using Labview 8, string that is sent is this: in,az1,bz1,ap0,bp0,fn2,trg
(initialize)
(chA impedance 50 ohms)
(chB """"""""""""""""")
(chA preset off)
(chB""""""""""")
(time interval)
(trigger measurement)

CHANNEL A AND B IMPEDANCE COMMANDS ARE GUESSES!!!!

The result is a hang with no measurement.
If I forgo the impedance settings via gbib (doing it manually), I will 
get an error (front panel 1.0). Manual says this is an invalid HPIB 
alpha command sent. I will get a measurement. It takes 1.5 sec or so.

I'm on vacation for the next two weeks. This am will be busy. Will be 
free 16Z give or take.
Thanks,
Norm n3ykf





From magnus at rubidium.dyndns.org  Tue Oct 21 23:19:30 2008
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Wed, 22 Oct 2008 01:19:30 +0200
Subject: [time-nuts] HP 5335a opt 40 addendum
In-Reply-To: <48FD7240.1070308@stny.rr.com>
References: <48FD7240.1070308@stny.rr.com>
Message-ID: <48FE6382.5010203@rubidium.dyndns.org>

Norman J McSweyn wrote:
> Hi all!
> I'm having some trouble programming my 5335a. The manual that Agilent 
> has doesn't cover opt 40. Have psyched out several of the codes that 
> aren't in the manual.
> Using Labview 8, string that is sent is this: in,az1,bz1,ap0,bp0,fn2,trg
> (initialize)
> (chA impedance 50 ohms)
> (chB """"""""""""""""")
> (chA preset off)
> (chB""""""""""")
> (time interval)
> (trigger measurement)
> 
> CHANNEL A AND B IMPEDANCE COMMANDS ARE GUESSES!!!!

They are correct.

You do not say anything on trigger levels and other 040 settings 
thought. The programming example 13 indicates that you should do 
something like this:

in,fu2,co1,bs1,tr1,at+2.71,bt+3.14

This becomes

in  - Initialize
fu2 - Time Interval
co1 - Set COMA on
bs1 - Set SLOPE B to NEGATIVE
tr1 - Set TRIGGER LEVELS to REMOTE
at+2,71 - Set TRIGGER LEVEL A to +2,71 V
bt+3.14 - Set TRIGGER LEVEL B to +3,14 V

The programming example does not use the trg command!

> The result is a hang with no measurement.
> If I forgo the impedance settings via gbib (doing it manually), I will 
> get an error (front panel 1.0). Manual says this is an invalid HPIB 
> alpha command sent. I will get a measurement. It takes 1.5 sec or so.
> 
> I'm on vacation for the next two weeks. This am will be busy. Will be 
> free 16Z give or take.

I hope the above hints helps. I haven't tested them against my HP5335A 
(with option 040) but I could do the effort if you need additional 
assistance.

Cheers,
Magnus


From matt at smiffytech.com  Wed Oct 22 01:42:16 2008
From: matt at smiffytech.com (Matthew Smith)
Date: Wed, 22 Oct 2008 12:12:16 +1030
Subject: [time-nuts] Oncore, Trimble Antennae
Message-ID: <48FE84F8.5060200@smiffytech.com>

Hi Folks

Finally got the builder here who is going to put my GPS antennae up on 
the roof.

I don't have the hardware set up to connect my Trimble Ace II modules to 
anything but want to test the cables that I have made up here in my office.

Both the Trimble and Motorola modules use active antennae with 5V power 
- what I don't know is whether they are the same polarity.  The Motorola 
has 5V on the core of the coax - does anyone know if the Trimble ones do 
the same?  If so, I'll just chuck the Trimble antenna onto the Oncore 
module for testing.

Cheers

M

-- 
Matthew Smith
Smiffytech - Technology Consulting & Web Application Development
Business: http://www.smiffytech.com/
Personal: http://www.smiffysplace.com/
LinkedIn: http://www.linkedin.com/in/smiffy


From chris.kuethe at gmail.com  Wed Oct 22 02:08:59 2008
From: chris.kuethe at gmail.com (Chris Kuethe)
Date: Tue, 21 Oct 2008 19:08:59 -0700
Subject: [time-nuts] Oncore, Trimble Antennae
In-Reply-To: <48FE84F8.5060200@smiffytech.com>
References: <48FE84F8.5060200@smiffytech.com>
Message-ID: <91981b3e0810211908o1f29215ke173f5bdc6d002df@mail.gmail.com>

On Tue, Oct 21, 2008 at 6:42 PM, Matthew Smith <matt at smiffytech.com> wrote:
> Both the Trimble and Motorola modules use active antennae with 5V power
> - what I don't know is whether they are the same polarity.  The Motorola
> has 5V on the core of the coax - does anyone know if the Trimble ones do
> the same?  If so, I'll just chuck the Trimble antenna onto the Oncore
> module for testing.

all my trimbles and oncores have +5 on center, ground on shield...

-- 
GDB has a 'break' feature; why doesn't it have 'fix' too?


From matt at smiffytech.com  Wed Oct 22 02:46:34 2008
From: matt at smiffytech.com (Matthew Smith)
Date: Wed, 22 Oct 2008 13:16:34 +1030
Subject: [time-nuts] Oncore, Trimble Antennae
Message-ID: <48FE940A.9010300@smiffytech.com>

Quoth Chris Kuethe:

 >all my trimbles and oncores have +5 on center, ground on shield...

Thanks Chris.  I had guessed that would be the case and was on the verge 
of doing a test but decided at the last minute "better safe than sorry".

And the Trimble antenna works just fine on the Oncore.  The only reason 
I'm putting two up there is so that I've got an unpowered, redundant 
spare.  (Using a splitter downstairs.)

Cheers

M

-- 
Matthew Smith
Smiffytech - Technology Consulting & Web Application Development
Business: http://www.smiffytech.com/
Personal: http://www.smiffysplace.com/
LinkedIn: http://www.linkedin.com/in/smiffy



From kyrrin at bluefeathertech.com  Wed Oct 22 02:54:38 2008
From: kyrrin at bluefeathertech.com (Bruce Lane)
Date: Tue, 21 Oct 2008 19:54:38 -0700
Subject: [time-nuts] Offlist for a while
Message-ID: <200810211954380545.0FD1DFA3@192.168.42.129>

Fellow clock-tickers,

	I'm going to be offlist for about a month to take care of some personal stuff. I'll be back on around Nov. 21st.

	Happy tweaking.


-=-=-=-=-=-=-=-=-=-=-=-
Bruce Lane, Owner & Head Hardware Heavy,
Blue Feather Technologies -- http://www.bluefeathertech.com
kyrrin (at) bluefeathertech do/t c=o=m
"Quid Malmborg in Plano..."



From tvb at LeapSecond.com  Wed Oct 22 03:04:23 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Tue, 21 Oct 2008 20:04:23 -0700
Subject: [time-nuts] Oncore, Trimble Antennae
References: <48FE84F8.5060200@smiffytech.com>
	<91981b3e0810211908o1f29215ke173f5bdc6d002df@mail.gmail.com>
Message-ID: <000901c933f2$e577ddb0$0500a8c0@pc52>

> Both the Trimble and Motorola modules use active antennae with 5V power 
> - what I don't know is whether they are the same polarity.

> all my trimbles and oncores have +5 on center, ground on shield...

I'd be interested to know if any antennas are in fact the other
way around. Never even considered that.

Now if GPS antennas just worked like DC motors, then maybe
a wrong polarity would make your altitude come out negative
or perhaps time would even count backwards...  ;-)

/tvb



From cfharris at erols.com  Wed Oct 22 04:31:41 2008
From: cfharris at erols.com (Chuck Harris)
Date: Wed, 22 Oct 2008 00:31:41 -0400
Subject: [time-nuts] Oncore, Trimble Antennae
In-Reply-To: <000901c933f2$e577ddb0$0500a8c0@pc52>
References: <48FE84F8.5060200@smiffytech.com>	<91981b3e0810211908o1f29215ke173f5bdc6d002df@mail.gmail.com>
	<000901c933f2$e577ddb0$0500a8c0@pc52>
Message-ID: <48FEACAD.3070903@erols.com>

Tom Van Baak wrote:
>> Both the Trimble and Motorola modules use active antennae with 5V power 
>> - what I don't know is whether they are the same polarity.
> 
>> all my trimbles and oncores have +5 on center, ground on shield...
> 
> I'd be interested to know if any antennas are in fact the other
> way around. Never even considered that.

It would have been fairly trivial for them to put a bridge rectifier
before the amplifier's power stuff, allowing for either polarity.

I always try to do that kind of thing (when I can) in my designs...
I wonder if they did?

-Chuck Harris


From normn3ykf at stny.rr.com  Wed Oct 22 04:32:41 2008
From: normn3ykf at stny.rr.com (Norman J McSweyn)
Date: Wed, 22 Oct 2008 00:32:41 -0400
Subject: [time-nuts] HP 5335a opt 40 addendum
In-Reply-To: <48FE6382.5010203@rubidium.dyndns.org>
References: <48FD7240.1070308@stny.rr.com>
	<48FE6382.5010203@rubidium.dyndns.org>
Message-ID: <48FEACE9.80905@stny.rr.com>

Magnus,
Thanks for the enlightenment!
I modified the driver that NI has on their site. Works. Have been 
manually setting the trigger levels on the front panel. Now know how to 
use the -40 to do it.

I'll further modify the driver in the AM.

The manual I have doesn't have programming example 13.

I take it that the instrument will trigger automatically when the 
conditions are met?

I'm comparing the 1pps output from an M12+t to the divided down 10MHz 
out from a Thunderbolt.

Next hurdle is to do something with the collected data.

Thanks,
Norm




From matt at smiffytech.com  Wed Oct 22 05:13:34 2008
From: matt at smiffytech.com (Matthew Smith)
Date: Wed, 22 Oct 2008 15:43:34 +1030
Subject: [time-nuts] Oncore, Trimble Antennae
In-Reply-To: <48FEACAD.3070903@erols.com>
References: <48FE84F8.5060200@smiffytech.com>	<91981b3e0810211908o1f29215ke173f5bdc6d002df@mail.gmail.com>	<000901c933f2$e577ddb0$0500a8c0@pc52>
	<48FEACAD.3070903@erols.com>
Message-ID: <48FEB67E.4020102@smiffytech.com>

Quoth Chuck Harris at 2008-10-22 15:01...

>> I'd be interested to know if any antennas are in fact the other
>> way around. Never even considered that.
> 
> It would have been fairly trivial for them to put a bridge rectifier
> before the amplifier's power stuff, allowing for either polarity.
> 
> I always try to do that kind of thing (when I can) in my designs...
> I wonder if they did?

What, and use an extra component?  The accountants would never allow it!

M


-- 
Matthew Smith
Smiffytech - Technology Consulting & Web Application Development
Business: http://www.smiffytech.com/
Personal: http://www.smiffysplace.com/
LinkedIn: http://www.linkedin.com/in/smiffy


From kirbybq at bellsouth.net  Wed Oct 22 05:46:10 2008
From: kirbybq at bellsouth.net (Brian Kirby)
Date: Wed, 22 Oct 2008 00:46:10 -0500
Subject: [time-nuts] Oncore, Trimble Antennae
In-Reply-To: <48FEB67E.4020102@smiffytech.com>
References: <48FE84F8.5060200@smiffytech.com>	<91981b3e0810211908o1f29215ke173f5bdc6d002df@mail.gmail.com>	<000901c933f2$e577ddb0$0500a8c0@pc52>	<48FEACAD.3070903@erols.com>
	<48FEB67E.4020102@smiffytech.com>
Message-ID: <48FEBE22.9060806@bellsouth.net>

All the antenna's I have played with have been +5 volts for power.  Is 
anyone aware of any other voltages ?  (I know Garmin used +3V for some)



Matthew Smith wrote:
> Quoth Chuck Harris at 2008-10-22 15:01...
> 
>>> I'd be interested to know if any antennas are in fact the other
>>> way around. Never even considered that.
>> It would have been fairly trivial for them to put a bridge rectifier
>> before the amplifier's power stuff, allowing for either polarity.
>>
>> I always try to do that kind of thing (when I can) in my designs...
>> I wonder if they did?
> 
> What, and use an extra component?  The accountants would never allow it!
> 
> M
> 
> 


From bg at lysator.liu.se  Wed Oct 22 07:11:10 2008
From: bg at lysator.liu.se (=?ISO-8859-1?Q?Bj=F6rn?= Gabrielsson)
Date: Wed, 22 Oct 2008 09:11:10 +0200
Subject: [time-nuts] Oncore, Trimble Antennae
In-Reply-To: <48FEBE22.9060806@bellsouth.net>
References: <48FE84F8.5060200@smiffytech.com>
	<91981b3e0810211908o1f29215ke173f5bdc6d002df@mail.gmail.com>
	<000901c933f2$e577ddb0$0500a8c0@pc52>	<48FEACAD.3070903@erols.com>
	<48FEB67E.4020102@smiffytech.com>  <48FEBE22.9060806@bellsouth.net>
Message-ID: <1224659470.6071.14.camel@bg-desktop>

Hi Brian,

On Wed, 2008-10-22 at 00:46 -0500, Brian Kirby wrote:
> All the antenna's I have played with have been +5 volts for power.  Is 
> anyone aware of any other voltages ?  (I know Garmin used +3V for some)

Antcom antennas are often 2.5V to 24V.
Aeroantenna's standard versions eats 5V to 18V.
Novatel antennas are 4.5V to 18V
Have seen 28V antennas too. ;-)
Javad antennas are often 3V to 12V

--

   Bj?rn



From magnus at rubidium.dyndns.org  Wed Oct 22 07:56:35 2008
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Wed, 22 Oct 2008 09:56:35 +0200
Subject: [time-nuts] HP 5335a opt 40 addendum
In-Reply-To: <48FEACE9.80905@stny.rr.com>
References: <48FD7240.1070308@stny.rr.com>	<48FE6382.5010203@rubidium.dyndns.org>
	<48FEACE9.80905@stny.rr.com>
Message-ID: <48FEDCB3.4000807@rubidium.dyndns.org>

Dear Norm,

Norman J McSweyn wrote:
> Magnus,
> Thanks for the enlightenment!
> I modified the driver that NI has on their site. Works. Have been 
> manually setting the trigger levels on the front panel. Now know how to 
> use the -40 to do it.

Great! Happy to help!

> I'll further modify the driver in the AM.
> 
> The manual I have doesn't have programming example 13.

I haven't looked in detail, but I *think* the HP5335A manual on the HP 
site is the same as I have, and then you should have all the details you 
need.

> I take it that the instrument will trigger automatically when the 
> conditions are met?

Indeed it does.

> I'm comparing the 1pps output from an M12+t to the divided down 10MHz 
> out from a Thunderbolt.
> 
> Next hurdle is to do something with the collected data.

Way to go!

You should learn to calculate Allan deviation and friends. Not to hard.
You should learn to estimate drift rate and subtract that from 
measurements, since that is often ignored and the drift rate will form a 
lower floor for longer measurement runs. This is an error which is 
either canceled by locking or by software.

Cheers,
Magnus


From javier.serrano.pareja at gmail.com  Wed Oct 22 08:19:34 2008
From: javier.serrano.pareja at gmail.com (Javier Serrano)
Date: Wed, 22 Oct 2008 10:19:34 +0200
Subject: [time-nuts] OT: Open Hardware Repository
Message-ID: <83e48fa10810220119n3d3d6df6r348efc68ddca5d17@mail.gmail.com>

Dear nuts,

Sorry for this posting, only indirectly related to timing. For a long time
I've been toying with the idea of a web-based Open Hardware Repository, and
now it looks like we could allocate some resources to building it. Here are
some preliminary and unofficial specs:
http://ab-dep-co-ht.web.cern.ch/ab-dep-co-ht/documents/2008/Hardware/OHRFuncSpec.pdf.
I have not found anywhere a kind of repository which would match these
requirements completely. It's intended to be for PCB design, in a much more
humble scale, what source forge is for software or opencores.org is for HDL.
Since many of the designs we'd put there are timing-related, I thought I'd
ask you for feedback:
- Do you think this is a good idea?
- Does this exist already somewhere?
- Any comments on the specs?
Feel free to answer directly to me if you think this is really off topic. I
would not like to spoil the fine SNR of this list. If I see there's lots of
interest I will post a summary.

Thanks,

Javier

From cfharris at erols.com  Wed Oct 22 13:04:29 2008
From: cfharris at erols.com (Chuck Harris)
Date: Wed, 22 Oct 2008 09:04:29 -0400
Subject: [time-nuts] Oncore, Trimble Antennae
In-Reply-To: <48FEB67E.4020102@smiffytech.com>
References: <48FE84F8.5060200@smiffytech.com>	<91981b3e0810211908o1f29215ke173f5bdc6d002df@mail.gmail.com>	<000901c933f2$e577ddb0$0500a8c0@pc52>	<48FEACAD.3070903@erols.com>
	<48FEB67E.4020102@smiffytech.com>
Message-ID: <48FF24DD.4090004@erols.com>

Matthew Smith wrote:
> Quoth Chuck Harris at 2008-10-22 15:01...
> 
>>> I'd be interested to know if any antennas are in fact the other
>>> way around. Never even considered that.
>> It would have been fairly trivial for them to put a bridge rectifier
>> before the amplifier's power stuff, allowing for either polarity.
>>
>> I always try to do that kind of thing (when I can) in my designs...
>> I wonder if they did?
> 
> What, and use an extra component?  The accountants would never allow it!

That's really kind of funny, in 29 years as an engineer, I have never
had an accountant talk to me about design decisions.  I tell them what
it will cost, and they say ok.

-Chuck Harris


From sar10538 at gmail.com  Wed Oct 22 13:32:04 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Thu, 23 Oct 2008 02:32:04 +1300
Subject: [time-nuts] Oncore, Trimble Antennae
In-Reply-To: <48FF24DD.4090004@erols.com>
References: <48FE84F8.5060200@smiffytech.com>
	<91981b3e0810211908o1f29215ke173f5bdc6d002df@mail.gmail.com>
	<000901c933f2$e577ddb0$0500a8c0@pc52> <48FEACAD.3070903@erols.com>
	<48FEB67E.4020102@smiffytech.com> <48FF24DD.4090004@erols.com>
Message-ID: <1231b6a80810220632h69f9986aue6703c42fee2831b@mail.gmail.com>

2008/10/23 Chuck Harris <cfharris at erols.com>:
> Matthew Smith wrote:
>> Quoth Chuck Harris at 2008-10-22 15:01...
>>
>>>> I'd be interested to know if any antennas are in fact the other
>>>> way around. Never even considered that.
>>> It would have been fairly trivial for them to put a bridge rectifier
>>> before the amplifier's power stuff, allowing for either polarity.
>>>
>>> I always try to do that kind of thing (when I can) in my designs...
>>> I wonder if they did?
>>
>> What, and use an extra component?  The accountants would never allow it!
>
> That's really kind of funny, in 29 years as an engineer, I have never
> had an accountant talk to me about design decisions.  I tell them what
> it will cost, and they say ok.

So you never worked for Microsoft on the Xbox then :)

73
Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From james.p.lux at jpl.nasa.gov  Wed Oct 22 13:43:31 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Wed, 22 Oct 2008 06:43:31 -0700
Subject: [time-nuts] Oncore, Trimble Antennae
In-Reply-To: <48FEACAD.3070903@erols.com>
Message-ID: <C5247C13.1EF5%James.P.Lux@jpl.nasa.gov>




On 10/21/08 9:31 PM, "Chuck Harris" <cfharris at erols.com> wrote:

> Tom Van Baak wrote:
>>> Both the Trimble and Motorola modules use active antennae with 5V power
>>> - what I don't know is whether they are the same polarity.
>>
>>> all my trimbles and oncores have +5 on center, ground on shield...
>>
>> I'd be interested to know if any antennas are in fact the other
>> way around. Never even considered that.
>
> It would have been fairly trivial for them to put a bridge rectifier
> before the amplifier's power stuff, allowing for either polarity.
>
 But not so trivial to provide the DC blocks in the ground side of the coax.
The LNA is almost certainly some MMIC with RF ground==Vss

And, don't forget that these are cost sensitive devices. 4 diodes and their
installation and board real estate costs money, as would the extra couple
capacitors for the DC blocks, etc.
Jim



From cfharris at erols.com  Wed Oct 22 13:51:00 2008
From: cfharris at erols.com (Chuck Harris)
Date: Wed, 22 Oct 2008 09:51:00 -0400
Subject: [time-nuts] Oncore, Trimble Antennae
In-Reply-To: <1231b6a80810220632h69f9986aue6703c42fee2831b@mail.gmail.com>
References: <48FE84F8.5060200@smiffytech.com>	<91981b3e0810211908o1f29215ke173f5bdc6d002df@mail.gmail.com>	<000901c933f2$e577ddb0$0500a8c0@pc52>
	<48FEACAD.3070903@erols.com>	<48FEB67E.4020102@smiffytech.com>
	<48FF24DD.4090004@erols.com>
	<1231b6a80810220632h69f9986aue6703c42fee2831b@mail.gmail.com>
Message-ID: <48FF2FC4.90809@erols.com>



Steve Rooke wrote:
> 2008/10/23 Chuck Harris <cfharris at erols.com>:
>> Matthew Smith wrote:
>>> Quoth Chuck Harris at 2008-10-22 15:01...
>>>
>>>>> I'd be interested to know if any antennas are in fact the other
>>>>> way around. Never even considered that.
>>>> It would have been fairly trivial for them to put a bridge rectifier
>>>> before the amplifier's power stuff, allowing for either polarity.
>>>>
>>>> I always try to do that kind of thing (when I can) in my designs...
>>>> I wonder if they did?
>>> What, and use an extra component?  The accountants would never allow it!
>> That's really kind of funny, in 29 years as an engineer, I have never
>> had an accountant talk to me about design decisions.  I tell them what
>> it will cost, and they say ok.
> 
> So you never worked for Microsoft on the Xbox then :)

Nope!  I have always worked for companies that are well out
of the Fortune 500 range.  I am a Renaissance man, so I find
that smaller companies better appreciate my wide range of
skills.

-Chuck Harris


From cfharris at erols.com  Wed Oct 22 14:20:05 2008
From: cfharris at erols.com (Chuck Harris)
Date: Wed, 22 Oct 2008 10:20:05 -0400
Subject: [time-nuts] Oncore, Trimble Antennae
In-Reply-To: <C5247C13.1EF5%James.P.Lux@jpl.nasa.gov>
References: <C5247C13.1EF5%James.P.Lux@jpl.nasa.gov>
Message-ID: <48FF3695.9050506@erols.com>

Lux, James P wrote:
> 
> 
> On 10/21/08 9:31 PM, "Chuck Harris" <cfharris at erols.com> wrote:
> 
>> Tom Van Baak wrote:
>>>> Both the Trimble and Motorola modules use active antennae with 5V power
>>>> - what I don't know is whether they are the same polarity.
>>>> all my trimbles and oncores have +5 on center, ground on shield...
>>> I'd be interested to know if any antennas are in fact the other
>>> way around. Never even considered that.
>> It would have been fairly trivial for them to put a bridge rectifier
>> before the amplifier's power stuff, allowing for either polarity.
>>
>  But not so trivial to provide the DC blocks in the ground side of the coax.
> The LNA is almost certainly some MMIC with RF ground==Vss

Not any worse than providing the DC block on the center of the coax.

> And, don't forget that these are cost sensitive devices. 4 diodes and their
> installation and board real estate costs money, as would the extra couple
> capacitors for the DC blocks, etc.

There is certain to be one diode on the hot lead anyway... engineers get nervous
when they leave out stuff like that.. so adding a bridge would eliminate that
diode.  A quick check of Mouser gives me a cost difference (qty 1000) of one dime
for the added bridge and capacitor... 12 cents if there was no diode in the original
circuit.  Circuit boards on devices like hockey puck antennas tend to be sparsely
populated, so I don't think it would make any difference there.

It would be worth the cost if the antenna was meant to be a universal device,
but probably not if it was intended to be used on only one receiver.

-Chuck Harris


From james.p.lux at jpl.nasa.gov  Wed Oct 22 14:25:57 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Wed, 22 Oct 2008 07:25:57 -0700
Subject: [time-nuts] Oncore, Trimble Antennae
In-Reply-To: <48FF24DD.4090004@erols.com>
Message-ID: <C5248605.1EFD%James.P.Lux@jpl.nasa.gov>




On 10/22/08 6:04 AM, "Chuck Harris" <cfharris at erols.com> wrote:

> Matthew Smith wrote:
>> Quoth Chuck Harris at 2008-10-22 15:01...
>>
>>>> I'd be interested to know if any antennas are in fact the other
>>>> way around. Never even considered that.
>>> It would have been fairly trivial for them to put a bridge rectifier
>>> before the amplifier's power stuff, allowing for either polarity.
>>>
>>> I always try to do that kind of thing (when I can) in my designs...
>>> I wonder if they did?
>>
>> What, and use an extra component?  The accountants would never allow it!
>
> That's really kind of funny, in 29 years as an engineer, I have never
> had an accountant talk to me about design decisions.  I tell them what
> it will cost, and they say ok.


Lucky you...

In the consumer electronics world, they do BOM scrubs and whole multi
work-year analyses to figure out how to remove a few square millimeters of
PWB, or even better, what's the trade between some jumpers and a single
sided board and a double sided board, and do we really need plated through
holes.  I worked on a project where they spent about 4-6 work months to
eliminate a couple capacitors at a nickle each. When you're making
10,000,000 units, that nickle per cap turns into a million bucks, many times
the few tens of $K the engineering time cost.

In the space electronics world, you'd do the same BOM scrub, but there the
idea is to eliminate parts that might fail, or add mass, or require testing
(each different part in the part list adds something like $5K-$10K from a
testing, inventory control, etc. standpoint)


Jim



From james.p.lux at jpl.nasa.gov  Wed Oct 22 14:34:06 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Wed, 22 Oct 2008 07:34:06 -0700
Subject: [time-nuts] Oncore, Trimble Antennae
In-Reply-To: <48FF3695.9050506@erols.com>
Message-ID: <C52487EE.1F00%James.P.Lux@jpl.nasa.gov>




On 10/22/08 7:20 AM, "Chuck Harris" <cfharris at erols.com> wrote:

> Lux, James P wrote:
>>
>>
>> On 10/21/08 9:31 PM, "Chuck Harris" <cfharris at erols.com> wrote:
>>
>>> Tom Van Baak wrote:
>>>>> Both the Trimble and Motorola modules use active antennae with 5V power
>>>>> - what I don't know is whether they are the same polarity.
>>>>> all my trimbles and oncores have +5 on center, ground on shield...
>>>> I'd be interested to know if any antennas are in fact the other
>>>> way around. Never even considered that.
>>> It would have been fairly trivial for them to put a bridge rectifier
>>> before the amplifier's power stuff, allowing for either polarity.
>>>
>>  But not so trivial to provide the DC blocks in the ground side of the coax.
>> The LNA is almost certainly some MMIC with RF ground==Vss
>
> Not any worse than providing the DC block on the center of the coax.

There is a significantly different EMI/EMC impact for breaking the shield
than breaking the center conductor.  Might not be an issue for a GPS Active
Antenna, but it's something to think about (we have some coaxial DC blocks
at work that break both, but also apparently make mighty fine slot radiators
at 30 GHz).

>
>> And, don't forget that these are cost sensitive devices. 4 diodes and their
>> installation and board real estate costs money, as would the extra couple
>> capacitors for the DC blocks, etc.
>
> There is certain to be one diode on the hot lead anyway... engineers get
> nervous
> when they leave out stuff like that..

No.. I doubt there's a diode in the hot lead. These sorts of devices is a
low cost device designed to be hooked up a specific piece of equipment.
They'd trust that they designed the equipment it's connected to is of the
correct polarity. Hook it up backwards and it fries.

There's also the forward voltage drop issue.. One or two diodes in series is
a significant power consumption bump in a system where you're evaluated on
microjoules/fix.

so adding a bridge would eliminate that
> diode.  A quick check of Mouser gives me a cost difference (qty 1000) of one
> dime
> for the added bridge and capacitor... 12 cents if there was no diode in the
> original
> circuit.  Circuit boards on devices like hockey puck antennas tend to be
> sparsely
> populated, so I don't think it would make any difference there.

There's a non zero cost at the manufacturer for inventory costs and incoming
inspection, as well as the additional cost for the extra components in the
pick and place machine, and the reduced machine throughput.  This all adds
up.  For a lot of circuits, the "other costs" could be 10-20x the actual
parts cost, especially for inexpensive passives like resistors and
capacitors.


>
> It would be worth the cost if the antenna was meant to be a universal device,
> but probably not if it was intended to be used on only one receiver.


Which is why universal devices cost more.. (or, don't exist.. The price we
pay for leveraging off consumer commodity pricing is that what WE want isn't
made...it's something that's almost what we want.)

Jim




From normn3ykf at stny.rr.com  Wed Oct 22 15:01:21 2008
From: normn3ykf at stny.rr.com (Norman J McSweyn)
Date: Wed, 22 Oct 2008 11:01:21 -0400
Subject: [time-nuts] HP 5335a opt 40 addendum
In-Reply-To: <48FEDCB3.4000807@rubidium.dyndns.org>
References: <48FD7240.1070308@stny.rr.com>	<48FE6382.5010203@rubidium.dyndns.org>	<48FEACE9.80905@stny.rr.com>
	<48FEDCB3.4000807@rubidium.dyndns.org>
Message-ID: <48FF4041.8080804@stny.rr.com>

Magnus Danielson wrote:
> Dear Norm,
> 
> Norman J McSweyn wrote:
>> Magnus,
>> Thanks for the enlightenment!
>> I modified the driver that NI has on their site. Works. Have been 
>> manually setting the trigger levels on the front panel. Now know how to 
>> use the -40 to do it.
> 
> Great! Happy to help!
> 
>> I'll further modify the driver in the AM.
>>
>> The manual I have doesn't have programming example 13.
> 
> I haven't looked in detail, but I *think* the HP5335A manual on the HP 
> site is the same as I have, and then you should have all the details you 
> need.
Magnus,
Unfortunatly, the manual on Agilent's site is the one that I have, 
without the -40 addendum.
> 
>> I take it that the instrument will trigger automatically when the 
>> conditions are met?
> 
> Indeed it does.
> 
>> I'm comparing the 1pps output from an M12+t to the divided down 10MHz 
>> out from a Thunderbolt.
>>
>> Next hurdle is to do something with the collected data.
> 
> Way to go!
> 
> You should learn to calculate Allan deviation and friends. Not to hard.
> You should learn to estimate drift rate and subtract that from 
> measurements, since that is often ignored and the drift rate will form a 
> lower floor for longer measurement runs. This is an error which is 
> either canceled by locking or by software.
> 
Data is time stamped and in a text file. One file is the TI data from 
the 5335a, the other is part of the @@Hn (with the sawtooth correction) 
message from the M12+T. In the interest of ensuring that I have a useful 
data set, I need to find a way to use Excel to check that no seconds 
have been skipped. Then post process the TI measurement to reflect the 
1pps sawtooth.

The next steps are a mystery. I drive locomotives for a living. This is 
  a hobby!! Have been playing with math for a while now, so it's not a 
black art! Didier has a few pages on measurements and one with tvb's 
explanation of Allan deviation. This will be today's reading!!!

Translating this into an Excel spreadsheet is the next hurdle.

Comparing the two devices (Thunderbolt to M12+T) is rather banal. It's 
like comparing two types of apples together. Not much difference. 
However, it's a steep learning curve to get to this point.

Any pointers are welcome!

Thanks,
Norm n3ykf
> Cheers,
> Magnus
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 


From cfharris at erols.com  Wed Oct 22 15:21:51 2008
From: cfharris at erols.com (Chuck Harris)
Date: Wed, 22 Oct 2008 11:21:51 -0400
Subject: [time-nuts] Oncore, Trimble Antennae
In-Reply-To: <C52487EE.1F00%James.P.Lux@jpl.nasa.gov>
References: <C52487EE.1F00%James.P.Lux@jpl.nasa.gov>
Message-ID: <48FF450F.3090205@erols.com>

Lux, James P wrote:
...

>>>  But not so trivial to provide the DC blocks in the ground side of the coax.
>>> The LNA is almost certainly some MMIC with RF ground==Vss
>> Not any worse than providing the DC block on the center of the coax.
> 
> There is a significantly different EMI/EMC impact for breaking the shield
> than breaking the center conductor.  Might not be an issue for a GPS Active
> Antenna, but it's something to think about (we have some coaxial DC blocks
> at work that break both, but also apparently make mighty fine slot radiators
> at 30 GHz).

Yes, but we are talking about a GPS hockey puck, not a 30GHz device.  At
these "low" frequencies, life is pretty easy.  A little careful
pc layout work, and you could do the DC block using the board almost
entirely.

>>> And, don't forget that these are cost sensitive devices. 4 diodes and their
>>> installation and board real estate costs money, as would the extra couple
>>> capacitors for the DC blocks, etc.
>> There is certain to be one diode on the hot lead anyway... engineers get
>> nervous
>> when they leave out stuff like that..
> 
> No.. I doubt there's a diode in the hot lead. These sorts of devices is a
> low cost device designed to be hooked up a specific piece of equipment.
> They'd trust that they designed the equipment it's connected to is of the
> correct polarity. Hook it up backwards and it fries.
> 
> There's also the forward voltage drop issue.. One or two diodes in series is
> a significant power consumption bump in a system where you're evaluated on
> microjoules/fix.

Not a watch, but a hockey puck antenna.  The receivers that use hockey puck
antennas are typically powered by a car's electrical system.  They have to
ditch 8V anyway, might as well lose some of it in a pair of diodes.

> so adding a bridge would eliminate that
>> diode.  A quick check of Mouser gives me a cost difference (qty 1000) of one
>> dime
>> for the added bridge and capacitor... 12 cents if there was no diode in the
>> original
>> circuit.  Circuit boards on devices like hockey puck antennas tend to be
>> sparsely
>> populated, so I don't think it would make any difference there.
> 
> There's a non zero cost at the manufacturer for inventory costs and incoming
> inspection, as well as the additional cost for the extra components in the
> pick and place machine, and the reduced machine throughput.  This all adds
> up.  For a lot of circuits, the "other costs" could be 10-20x the actual
> parts cost, especially for inexpensive passives like resistors and
> capacitors.

Agreed.

>> It would be worth the cost if the antenna was meant to be a universal device,
>> but probably not if it was intended to be used on only one receiver.
> 
> 
> Which is why universal devices cost more.. (or, don't exist.. The price we
> pay for leveraging off consumer commodity pricing is that what WE want isn't
> made...it's something that's almost what we want.)

Yep!  Almost always true.  The hockey puck antennas, were sold as a product by
themselves, and there were a lot of receivers that used them.  I think motorola
and others thought of them as universal devices.... but I also think they thought
of them as disposable, so it isn't clear that they cared if you burned one out
by misapplication.

I have a spare around the shop somewhere.  If it isn't too destructive, I think
I'll open it up and take a look.

-Chuck Harris


From cfharris at erols.com  Wed Oct 22 15:33:36 2008
From: cfharris at erols.com (Chuck Harris)
Date: Wed, 22 Oct 2008 11:33:36 -0400
Subject: [time-nuts] Oncore, Trimble Antennae
In-Reply-To: <C5248605.1EFD%James.P.Lux@jpl.nasa.gov>
References: <C5248605.1EFD%James.P.Lux@jpl.nasa.gov>
Message-ID: <48FF47D0.4090609@erols.com>

Lux, James P wrote:

>> That's really kind of funny, in 29 years as an engineer, I have never
>> had an accountant talk to me about design decisions.  I tell them what
>> it will cost, and they say ok.
> 
> 
> Lucky you...

Not luck, but a conscious decision to stay out of consumer
electronics.  I could see the writing on the wall 30 years
ago.  Consumer electronics design and manufacturing in the US
is just biding its time, waiting for the last guy out to
switch off the lights.  I am glad I stayed out of it.

> In the consumer electronics world, they do BOM scrubs and whole multi
> work-year analyses to figure out how to remove a few square millimeters of
> PWB, or even better, what's the trade between some jumpers and a single
> sided board and a double sided board, and do we really need plated through
> holes.  I worked on a project where they spent about 4-6 work months to
> eliminate a couple capacitors at a nickle each. When you're making
> 10,000,000 units, that nickle per cap turns into a million bucks, many times
> the few tens of $K the engineering time cost.
> 
> In the space electronics world, you'd do the same BOM scrub, but there the
> idea is to eliminate parts that might fail, or add mass, or require testing
> (each different part in the part list adds something like $5K-$10K from a
> testing, inventory control, etc. standpoint)

There is nothing wrong with having to justify your design.  That is
what the design review process is all about.  I have never had to
justify a design to an accountant.  I have never met the accountant
that could design circuitry.

Kind of like an engineer framing houses... no, wait, I do that.

-Chuck Harris


From iovane at inwind.it  Wed Oct 22 20:14:06 2008
From: iovane at inwind.it (iovane at inwind.it)
Date: Wed, 22 Oct 2008 22:14:06 +0200
Subject: [time-nuts] LPRO lamp decay
Message-ID: <K95PJI$4615E0E068B49C27AF354E5B337D3D95@libero.it>

Maybe this could be of interest.

I have an LPRO continuously running since ending last January. Lamp volt was 7.92V.
As of October 22 (today, 9 months later) the voltage is 7.7V.
The voltage dropped by 0.22V.
The VCXO Volt was 6.7V, and now is 6.8V.
It is powered at 24V, and the temperature at the heatsinked baseplate is 40 ?C.
I see one could expect many years of operation from such surplus units.

73,
Antonio I8IOV



From iovane at inwind.it  Wed Oct 22 21:02:23 2008
From: iovane at inwind.it (iovane at inwind.it)
Date: Wed, 22 Oct 2008 23:02:23 +0200
Subject: [time-nuts] Question on crystal jumps
Message-ID: <K95RRZ$FAF15E0C201369F08F1E9E13C34A5EF0@libero.it>

I would be very pleased to know when (date and time) anybody
out there happened to record jumps in frequency of crystals.
I have stable (e-07) tuning forks which happen to jump too, 
and I don't understand why, even having under control 
temperature and air pressure. Sometimes they return to their 
prior frequency with another jump, and this could happen even
days later, sometimes they jump and then recover smoothly the
prior frequency in a short time (such as one hour).
I have no idea whether any correlations would exist between 
crystals and tuning forks jumps, regarding the causes that 
could trigger metastability, and hence I would have a look at 
crystal data in order to improve the base for future 
speculation.

Thanks in advance.
Antonio I8IOV




From namichie at gmail.com  Wed Oct 22 21:19:32 2008
From: namichie at gmail.com (Neville Michie)
Date: Thu, 23 Oct 2008 08:19:32 +1100
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <K95RRZ$FAF15E0C201369F08F1E9E13C34A5EF0@libero.it>
References: <K95RRZ$FAF15E0C201369F08F1E9E13C34A5EF0@libero.it>
Message-ID: <9AD69EF6-B8CD-496F-B504-DCD6A0B634FD@gmail.com>

Hi Antonio,

precise pendulum clocks also suffer rate jumps, the process of rate  
jumping
seems to be common to most time counting systems.

I have an LPRO rubidium oscillator. I mounted it on a heat sink with  
fins
and placed it in an insulated box. A small (40mm) fan is switched to  
control
the base-plate temperature at 40*C + or - 0.05*. As it warms up to  
the control point
the oscillator control voltage changes by 1 volt, so the oscillator  
control
voltage is very temperature sensitive. I do not think it will age  
beyond its
control range.
I hope that the temperature control will improve the frequency accuracy
by a large ratio.

cheers, Neville Michie




On 23/10/2008, at 8:02 AM, iovane@@inwind..it wrote:

> I would be very pleased to know when (date and time) anybody
> out there happened to record jumps in frequency of crystals.
> I have stable (e-07) tuning forks which happen to jump too,
> and I don't understand why, even having under control
> temperature and air pressure. Sometimes they return to their
> prior frequency with another jump, and this could happen even
> days later, sometimes they jump and then recover smoothly the
> prior frequency in a short time (such as one hour).
> I have no idea whether any correlations would exist between
> crystals and tuning forks jumps, regarding the causes that
> could trigger metastability, and hence I would have a look at
> crystal data in order to improve the base for future
> speculation.
>
> Thanks in advance.
> Antonio I8IOV
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ 
> time-nuts
> and follow the instructions there.



From bg at lysator.liu.se  Wed Oct 22 21:23:25 2008
From: bg at lysator.liu.se (=?ISO-8859-1?Q?Bj=F6rn?= Gabrielsson)
Date: Wed, 22 Oct 2008 23:23:25 +0200
Subject: [time-nuts] OT: connector identification
Message-ID: <1224710605.6071.28.camel@bg-desktop>

Hi List,

I have a coax connector that I would like to identify. Se attached
picture. 

To the left is a female TNC for reference. The unknown male is attached
to the cable. Unknown female to the upper left as part of a "T" adapter.

It looks kind of a smaller version of TNC. It is slighly larger than
SMA. Female diameter is 5/16", whereas TNC is 7/16" and SMA is 4/16" -
according to my simple measurement.

Anyone recognizing this connector?

thanks,

    Bj?rn
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From richard at karlquist.com  Wed Oct 22 21:23:57 2008
From: richard at karlquist.com (Rick Karlquist)
Date: Wed, 22 Oct 2008 14:23:57 -0700 (PDT)
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <K95RRZ$FAF15E0C201369F08F1E9E13C34A5EF0@libero.it>
References: <K95RRZ$FAF15E0C201369F08F1E9E13C34A5EF0@libero.it>
Message-ID: <23695.192.25.240.225.1224710637.squirrel@webmail.sonic.net>

I'm not quite sure what the question is here, but when
we made 10811 oscillators at HP, "jumps happened".  Some
crystals were better than others, but no crystal was immune
from jumps.  With good quality crystals, you might be able
to put an upper bound on the magnitude of jumps, like 10-9,
but not on the time between jumps.  I also noticed that there
didn't seem to be any correlation between jump activity
and stability between jumps.  You could have an oscillator
with really low aging, say a few parts in 1E11 per day that
looked really good for quite a while, but then the frequency
jumps.  After you've controlled everything you can about the
crystal process, the electronics, the oven and the environment,
you are still left with jumps.  If you want no jumps, go to
an atomic standard like rubidium.  There are mechanisms that
can cause jumps in rubidium standards as well, but good
rubidium standards don't jump.

Rick Karlquist N6RK


iovane\@inwind\.it wrote:
> I would be very pleased to know when (date and time) anybody
> out there happened to record jumps in frequency of crystals.
> I have stable (e-07) tuning forks which happen to jump too,
> and I don't understand why, even having under control
> temperature and air pressure. Sometimes they return to their
> prior frequency with another jump, and this could happen even
> days later, sometimes they jump and then recover smoothly the
> prior frequency in a short time (such as one hour).
> I have no idea whether any correlations would exist between
> crystals and tuning forks jumps, regarding the causes that
> could trigger metastability, and hence I would have a look at
> crystal data in order to improve the base for future
> speculation.
>
> Thanks in advance.
> Antonio I8IOV
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>




From mfeher at eozinc.com  Wed Oct 22 21:40:00 2008
From: mfeher at eozinc.com (Mike Feher)
Date: Wed, 22 Oct 2008 17:40:00 -0400
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <K95RRZ$FAF15E0C201369F08F1E9E13C34A5EF0@libero.it>
References: <K95RRZ$FAF15E0C201369F08F1E9E13C34A5EF0@libero.it>
Message-ID: <5346B43A3CF8495CAC76CBC9AA30FB2A@gsmacdq14es>

Are you sure it is the tuning fork and not the reference for your counter? -
73 - Mike

 
 
Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960
 
 

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of iovane at inwind.it
Sent: Wednesday, October 22, 2008 5:02 PM
To: time-nuts
Subject: [time-nuts] Question on crystal jumps

I would be very pleased to know when (date and time) anybody
out there happened to record jumps in frequency of crystals.
I have stable (e-07) tuning forks which happen to jump too, 
and I don't understand why, even having under control 
temperature and air pressure. Sometimes they return to their 
prior frequency with another jump, and this could happen even
days later, sometimes they jump and then recover smoothly the
prior frequency in a short time (such as one hour).
I have no idea whether any correlations would exist between 
crystals and tuning forks jumps, regarding the causes that 
could trigger metastability, and hence I would have a look at 
crystal data in order to improve the base for future 
speculation.

Thanks in advance.
Antonio I8IOV



_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



From kirbybq at bellsouth.net  Wed Oct 22 21:55:39 2008
From: kirbybq at bellsouth.net (Brian Kirby)
Date: Wed, 22 Oct 2008 16:55:39 -0500
Subject: [time-nuts] OT: connector identification
In-Reply-To: <1224710605.6071.28.camel@bg-desktop>
References: <1224710605.6071.28.camel@bg-desktop>
Message-ID: <48FFA15B.5010703@bellsouth.net>

Might be a SMB.....

Bj?rn Gabrielsson wrote:
> Hi List,
> 
> I have a coax connector that I would like to identify. Se attached
> picture. 
> 
> To the left is a female TNC for reference. The unknown male is attached
> to the cable. Unknown female to the upper left as part of a "T" adapter.
> 
> It looks kind of a smaller version of TNC. It is slighly larger than
> SMA. Female diameter is 5/16", whereas TNC is 7/16" and SMA is 4/16" -
> according to my simple measurement.
> 
> Anyone recognizing this connector?
> 
> thanks,
> 
>     Bj?rn
> 
> 
> ------------------------------------------------------------------------
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.


From iovane at inwind.it  Wed Oct 22 21:57:16 2008
From: iovane at inwind.it (iovane at inwind.it)
Date: Wed, 22 Oct 2008 23:57:16 +0200
Subject: [time-nuts] Question on crystal jumps
Message-ID: <K95UBG$3591C92E943317EA8FE4CDE480D47AB4@libero.it>

> Hi Antonio,
> 
> precise pendulum clocks also suffer rate jumps, the process
> of rate jumping seems to be common to most time counting 
> systems.

Thanks, I was missing this info.

> I have an LPRO rubidium oscillator. I mounted it on a heat
> sink with fins and placed it in an insulated box. A small 
> (40mm) fan is switched to control the base-plate 
> temperature at 40*C + or - 0.05*. As it warms up to the 
> control point the oscillator control voltage changes by 1
> volt, so the oscillator control voltage is very temperature
> sensitive. I do not think it will age beyond its
> control range.

In this case, I believe it is a design spec. I experience the 
same with several LPRO's. The crystal inside LPRO has an heatsink itself, which would improve the thermal coupling between it and the rest of the assembly. I think it is expected to run at its nominal frequency after the warm-up of the whole unit. It may have beed designed accordingly.

73,
Antonio I8IOV



From bruce.griffiths at xtra.co.nz  Wed Oct 22 22:01:25 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Thu, 23 Oct 2008 11:01:25 +1300
Subject: [time-nuts] OT: connector identification
In-Reply-To: <48FFA15B.5010703@bellsouth.net>
References: <1224710605.6071.28.camel@bg-desktop>
	<48FFA15B.5010703@bellsouth.net>
Message-ID: <48FFA2B5.1020104@xtra.co.nz>

Brian Kirby wrote:
> Might be a SMB.....
>
> Bj?rn Gabrielsson wrote:
>   
>> Hi List,
>>
>> I have a coax connector that I would like to identify. Se attached
>> picture. 
>>
>> To the left is a female TNC for reference. The unknown male is attached
>> to the cable. Unknown female to the upper left as part of a "T" adapter.
>>
>> It looks kind of a smaller version of TNC. It is slighly larger than
>> SMA. Female diameter is 5/16", whereas TNC is 7/16" and SMA is 4/16" -
>> according to my simple measurement.
>>
>> Anyone recognizing this connector?
>>
>> thanks,
>>
>>     Bj?rn
>>
>>
>>     
Not an SMB as mated SMB connectors don't have a threaded retainer and
are smaller than an SMA.
SMC is the threaded version and has same internal diameter as SMB.

Bruce


From iovane at inwind.it  Wed Oct 22 22:06:04 2008
From: iovane at inwind.it (iovane at inwind.it)
Date: Thu, 23 Oct 2008 00:06:04 +0200
Subject: [time-nuts] Question on crystal jumps
Message-ID: <K95UQ4$48083C91C65FA4E4C6B80E1A7FAAEC4F@libero.it>

Hi Rick

> I'm not quite sure what the question is here....
> ....

The question is:
may anybody tell me (date and time) when a crystal jumped?
(a sample response could be: my crystal jumped on January 22, 2006 12:25 UT).

I would like to map in time as many jumps as possible.

I hope someone in the list has a log of his jumps.

Thanks and 73,
Antonio I8IOV



From iovane at inwind.it  Wed Oct 22 22:19:15 2008
From: iovane at inwind.it (iovane at inwind.it)
Date: Thu, 23 Oct 2008 00:19:15 +0200
Subject: [time-nuts] Question on crystal jumps
Message-ID: <K95VC3$5A93FEA5D3557405BCC98361F70C0EE3@libero.it>

> Are you sure it is the tuning fork and not the reference 
> for your counter? -
> 73 - Mike

Hi Mike,

the tuning fork jumps were in the order of e-7, while the references were a HP 10811 and a Racal Opt 04E both in the range of e-10.

Thanks and 73,
ANtonio




From bg at lysator.liu.se  Wed Oct 22 22:25:43 2008
From: bg at lysator.liu.se (=?ISO-8859-1?Q?Bj=F6rn?= Gabrielsson)
Date: Thu, 23 Oct 2008 00:25:43 +0200
Subject: [time-nuts] OT: connector identification
In-Reply-To: <48FFA26F.2040803@bellsouth.net>
References: <1224710605.6071.28.camel@bg-desktop>
	<48FFA26F.2040803@bellsouth.net>
Message-ID: <1224714343.6071.39.camel@bg-desktop>

Brian,

No its not an SMC. See attached photo. 

>From the left,

male and female SMA, female and male unkown and to the right the smaller
male SMC.

--

   Bj?rn

On Wed, 2008-10-22 at 17:00 -0500, Brian Kirby wrote:
> It may be SMC now that I looked it up.  A connector guide is attached....
> 
> 
> Bj?rn Gabrielsson wrote:
> > Hi List,
> > 
> > I have a coax connector that I would like to identify. Se attached
> > picture. 
> > 
> > To the left is a female TNC for reference. The unknown male is attached
> > to the cable. Unknown female to the upper left as part of a "T" adapter.
> > 
> > It looks kind of a smaller version of TNC. It is slighly larger than
> > SMA. Female diameter is 5/16", whereas TNC is 7/16" and SMA is 4/16" -
> > according to my simple measurement.
> > 
> > Anyone recognizing this connector?
> > 
> > thanks,
> > 
> >     Bj?rn
> > 
> > 
> > ------------------------------------------------------------------------
> > 
> > 
> > ------------------------------------------------------------------------
> > 
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at febo.com
> > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
-------------- next part --------------
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From iovane at inwind.it  Wed Oct 22 22:34:53 2008
From: iovane at inwind.it (iovane at inwind.it)
Date: Thu, 23 Oct 2008 00:34:53 +0200
Subject: [time-nuts] Question on crystal jumps
Message-ID: <K95W25$412FFB6E9EE1722FCE58F65E688730B3@libero.it>

Neville,

> Hi Antonio,
> 
> precise pendulum clocks also suffer rate jumps, the process
> of rate jumping seems to be common to most time counting 
> systems.

I have an interest in this. May you point me to any references?

73,
Antonio I8IOV





From bill at iaxs.net  Wed Oct 22 22:48:07 2008
From: bill at iaxs.net (Bill Hawkins)
Date: Wed, 22 Oct 2008 17:48:07 -0500
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <K95VC3$5A93FEA5D3557405BCC98361F70C0EE3@libero.it>
References: <K95VC3$5A93FEA5D3557405BCC98361F70C0EE3@libero.it>
Message-ID: <02150B5B362B4B3BB378465B54C24BB2@cyrus>

College freshman physics (in 1955) included a story about the
probability
of all atoms in a chalk board eraser moving the same way at the same
time,
causing it to jump off the board. The incredibly small probability of
that
happening was what kept solid matter apparently inert.

I would not discourage you from looking for an intergalactic cause of
jumps,
but I think the laws of probability are quite sound. Perhaps you could
prove
that by describing the randomness of the jumps in many crystals in many
places.

Bill Hawkins



From ronald.p.smith at btinternet.com  Wed Oct 22 23:08:56 2008
From: ronald.p.smith at btinternet.com (Ron Smith)
Date: Thu, 23 Oct 2008 00:08:56 +0100
Subject: [time-nuts] Question on crystal jumps
References: <K95UQ4$48083C91C65FA4E4C6B80E1A7FAAEC4F@libero.it>
Message-ID: <002401c9349b$29ef1780$4201a8c0@G3SVW>

Hello Antonio,

A.W.Ladner and C.R.Stoner in their book "Short Wave Wireless Communication"
describe a phenomenon called "stepping", which may be the same effect as the 
jumps you are
investigating.

The book is quite old, 4th edition published in 1942 by Chapman and Hall,
and refers (on page 321) to stepping in X- and Y-cut crystals, which may not
be common these days, but perhaps crystals of all cuts are affected to some 
degree.

The text says the curve of frequency against plate thickness does not give a
straight line, but has discontinuities in it. These discontinuities they
call "stepping points" and are a result of edge vibrations coinciding with
sub-multiple frequencies of the wanted thickness vibration mode. The degree
of coupling between the wanted and unwanted modes varies with crystal
dimension. If there is zero coupling, the stepping points should not affect
the main oscillation. But perhaps even the smallest change in dimension can
cause it to cross one of these discontinuities and jump to and fro? I
suspect that crystal sensitivity to stepping or jumping may be correlated
with its temperature coefficient, although there are other factors
(including gravitational) that influence frequency of oscillation at very
small levels.

Antonio, these frequency jumps are not a phenomenon I have come across 
myself, so I have nothing to log,
but I am interested in what you discover. Wouldn't it be fascinating if you 
discovered a global trigger to many simultaneous frequency steps?
The book reference is a bit old I'm afraid - things have moved on since 
1942.
Good luck.


Ron Smith
G3SVW




----- Original Message ----- 
From: <iovane at inwind.it>
To: "time-nuts" <time-nuts at febo.com>
Sent: Wednesday, October 22, 2008 11:06 PM
Subject: Re: [time-nuts] Question on crystal jumps


> Hi Rick
>
>> I'm not quite sure what the question is here....
>> ....
>
> The question is:
> may anybody tell me (date and time) when a crystal jumped?
> (a sample response could be: my crystal jumped on January 22, 2006 12:25 
> UT).
>
> I would like to map in time as many jumps as possible.
>
> I hope someone in the list has a log of his jumps.
>
> Thanks and 73,
> Antonio I8IOV
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 




From mikes at flatsurface.com  Wed Oct 22 23:14:43 2008
From: mikes at flatsurface.com (Mike S)
Date: Wed, 22 Oct 2008 19:14:43 -0400
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <02150B5B362B4B3BB378465B54C24BB2@cyrus>
References: <K95VC3$5A93FEA5D3557405BCC98361F70C0EE3@libero.it>
	<02150B5B362B4B3BB378465B54C24BB2@cyrus>
Message-ID: <20081022232858.13D6E1165C3@hamburg.alientech.net>

At 06:48 PM 10/22/2008, Bill Hawkins wrote...
>I would not discourage you from looking for an intergalactic cause of 
>jumps, but I think the laws of probability are quite sound.

OTOH, perhaps Yoda is correct - "I feel a disturbance in the force." 
:-)



From brooke at pacific.net  Wed Oct 22 23:39:34 2008
From: brooke at pacific.net (Brooke Clarke)
Date: Wed, 22 Oct 2008 16:39:34 -0700
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <002401c9349b$29ef1780$4201a8c0@G3SVW>
References: <K95UQ4$48083C91C65FA4E4C6B80E1A7FAAEC4F@libero.it>
	<002401c9349b$29ef1780$4201a8c0@G3SVW>
Message-ID: <48FFB9B6.9080707@pacific.net>

Hi:

A possible explanation is cosmic rays.  The actual particle that gets to the 
surface of the Earth is so energetic that it would take a very thick lead 
shield to stop them.  The Earth has enough mass that they can not go all the 
way through.  http://en.wikipedia.org/wiki/Muon

So a test would be to stack a few crystals very close together (it's just plain 
geometry) and monitor their frequency to look for coincident jumps.

Have Fun,

Brooke Clarke
http://www.prc68.com/P/Prod.html  Products I make and sell
http://www.prc68.com/Alpha.shtml  All my web pages listed based on html name
http://www.PRC68.com
http://www.precisionclock.com
http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Web Cam

Ron Smith wrote:
> Hello Antonio,
> 
> A.W.Ladner and C.R.Stoner in their book "Short Wave Wireless Communication"
> describe a phenomenon called "stepping", which may be the same effect as the 
> jumps you are
> investigating.
> 
> The book is quite old, 4th edition published in 1942 by Chapman and Hall,
> and refers (on page 321) to stepping in X- and Y-cut crystals, which may not
> be common these days, but perhaps crystals of all cuts are affected to some 
> degree.
> 
> The text says the curve of frequency against plate thickness does not give a
> straight line, but has discontinuities in it. These discontinuities they
> call "stepping points" and are a result of edge vibrations coinciding with
> sub-multiple frequencies of the wanted thickness vibration mode. The degree
> of coupling between the wanted and unwanted modes varies with crystal
> dimension. If there is zero coupling, the stepping points should not affect
> the main oscillation. But perhaps even the smallest change in dimension can
> cause it to cross one of these discontinuities and jump to and fro? I
> suspect that crystal sensitivity to stepping or jumping may be correlated
> with its temperature coefficient, although there are other factors
> (including gravitational) that influence frequency of oscillation at very
> small levels.
> 
> Antonio, these frequency jumps are not a phenomenon I have come across 
> myself, so I have nothing to log,
> but I am interested in what you discover. Wouldn't it be fascinating if you 
> discovered a global trigger to many simultaneous frequency steps?
> The book reference is a bit old I'm afraid - things have moved on since 
> 1942.
> Good luck.
> 
> 
> Ron Smith
> G3SVW
> 
> 
> 
> 
> ----- Original Message ----- 
> From: <iovane at inwind.it>
> To: "time-nuts" <time-nuts at febo.com>
> Sent: Wednesday, October 22, 2008 11:06 PM
> Subject: Re: [time-nuts] Question on crystal jumps
> 
> 
>> Hi Rick
>>
>>> I'm not quite sure what the question is here....
>>> ....
>> The question is:
>> may anybody tell me (date and time) when a crystal jumped?
>> (a sample response could be: my crystal jumped on January 22, 2006 12:25 
>> UT).
>>
>> I would like to map in time as many jumps as possible.
>>
>> I hope someone in the list has a log of his jumps.
>>
>> Thanks and 73,
>> Antonio I8IOV
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to 
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
> 
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 


From namichie at gmail.com  Wed Oct 22 23:47:04 2008
From: namichie at gmail.com (Neville Michie)
Date: Thu, 23 Oct 2008 10:47:04 +1100
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <K95W25$412FFB6E9EE1722FCE58F65E688730B3@libero.it>
References: <K95W25$412FFB6E9EE1722FCE58F65E688730B3@libero.it>
Message-ID: <31240487-E84E-471F-8C3B-1BC6E47609A0@gmail.com>

Hi,
In : Accurate Clock Pendulums by Robert Matthys (2004) Oxford  
University Press ISBN 0198529716, Pp264
In Chapter 8 , "The Allen variance and the rms time error", on page 38
he writes:
Figure 8.1 shows another characteristic of pendulum clocks - the  
clock will run relatively
smoothly at one rate , and then after 3 - 6 months it will suddenly  
jump to a new rate
as shown if Fig 8.1.

He goes on to say that this is part of a random walk process.

I hope that is of some help.
Neville MIchie

On 23/10/2008, at 9:34 AM, iovane@@inwind..it wrote:

> Neville,
>
>> Hi Antonio,
>>
>> precise pendulum clocks also suffer rate jumps, the process
>> of rate jumping seems to be common to most time counting
>> systems.
>
> I have an interest in this. May you point me to any references?
>
> 73,
> Antonio I8IOV
>
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ 
> time-nuts
> and follow the instructions there.



From GandalfG8 at aol.com  Wed Oct 22 23:50:35 2008
From: GandalfG8 at aol.com (GandalfG8 at aol.com)
Date: Wed, 22 Oct 2008 19:50:35 EDT
Subject: [time-nuts] OT: connector identification
Message-ID: <cfc.4624f489.3631164b@aol.com>

 
In a message dated 22/10/2008 22:26:45 GMT Daylight Time, bg at lysator.liu.se  
writes:

I have a  coax connector that I would like to identify. Se attached
picture.  

To the left is a female TNC for reference. The unknown male is  attached
to the cable. Unknown female to the upper left as part of a "T"  adapter.

It looks kind of a smaller version of TNC. It is slighly  larger than
SMA. Female diameter is 5/16", whereas TNC is 7/16" and SMA is  4/16" -
according to my simple measurement.

Anyone recognizing this  connector?



----------------
Hi Bjorn
 
Quick answer is no, but "miniature TNC" would seem to be a possible  
contender.
 
Unfortunately, although I've seen enough references to miniature TNCs to  
know they exist, I've not yet found a photo or drawing.
I'm pretty sure I have some equipment with them fitted but, if I have, it  
will be in storage so not something to be confirmed in a hurry.
 
What you've got, as you say, is certainly not SMB or SMC but is about the  
same size as SM.
And yes, that is SM and not SMA.
The SM connector, not very common but I've got some Greenpar SM  adapters, is 
similar to SMA, in terms of pin and dielectric arrangement, but  bigger, 
whilst what you have is a very close match to the TNC  configuration, but 
smaller.....
so, in size at least, they sort of meet in the middle:-)
 
A while ago I bought a Greenpar adapter kit that was a special  for the UK 
military and probably the biggest kit  Greenpar made.
Alongside most, if not all, the common connectors we're all used to was  
quite a range I'd never heard of before, including SM, HN, SC, Pattern 8,  Pattern 
12, etc etc.
They generally seem to be a "close but not quite" match to more common  
connectors but so far I've not seen any of them in commercial catalogues.
 
I suspect your connectors might be similarly unusual but still think Mini  
TNC is the most likely option..... although happy to accept that somebody will  
probably prove me wrong within a few minutse of this being posted:-)
 
regards
 
Nigel
GM8PZR
 
 
 
 
 

From brooke at pacific.net  Thu Oct 23 00:00:08 2008
From: brooke at pacific.net (Brooke Clarke)
Date: Wed, 22 Oct 2008 17:00:08 -0700
Subject: [time-nuts] OT: connector identification
In-Reply-To: <1224710605.6071.28.camel@bg-desktop>
References: <1224710605.6071.28.camel@bg-desktop>
Message-ID: <48FFBE88.2090707@pacific.net>

Hi Bj?rn:

The Pasternack hard copy catalog, or the on line version:
http://www.pasternack.com/pdf/catalog/ConnectorIdentifier.pdf
are a handy reference to identify coax connectors.

It's handy to have a pair of digital vernier calipers with switchable metric 
and inch displays to get the key dimensions needed.

Have Fun,

Brooke Clarke
http://www.prc68.com/P/Prod.html  Products I make and sell
http://www.prc68.com/Alpha.shtml  All my web pages listed based on html name
http://www.PRC68.com
http://www.precisionclock.com
http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Web Cam

Bj?rn Gabrielsson wrote:
> Hi List,
> 
> I have a coax connector that I would like to identify. Se attached
> picture. 
> 
> To the left is a female TNC for reference. The unknown male is attached
> to the cable. Unknown female to the upper left as part of a "T" adapter.
> 
> It looks kind of a smaller version of TNC. It is slighly larger than
> SMA. Female diameter is 5/16", whereas TNC is 7/16" and SMA is 4/16" -
> according to my simple measurement.
> 
> Anyone recognizing this connector?
> 
> thanks,
> 
>     Bj?rn
> 
> 
> ------------------------------------------------------------------------
> 
> 
> ------------------------------------------------------------------------
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.



From james.p.lux at jpl.nasa.gov  Thu Oct 23 00:05:24 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Wed, 22 Oct 2008 17:05:24 -0700
Subject: [time-nuts] OT: connector identification
In-Reply-To: <1224710605.6071.28.camel@bg-desktop>
References: <1224710605.6071.28.camel@bg-desktop>
Message-ID: <ECE7A93BD093E1439C20020FBE87C47FEB523ED589@ALTPHYEMBEVSP20.RES.AD.JPL>

There IS a mini-TNC as I recall. My ancient (80s vintage) cellphone had such a thing on the antenna.  There's also something referred to as a mini-UHF (presumably a small PL-259), but the amphenol catalog pitures show the serrated top of the female, and yours are smooth.  The thread was 3/8" -24 threads/inch

James Lux, P.E.
Task Manager, SOMD Software Defined Radios
Flight Communications Systems Section
Jet Propulsion Laboratory
4800 Oak Grove Drive, Mail Stop 161-213
Pasadena, CA, 91109
+1(818)354-2075 phone
+1(818)393-6875 fax

> -----Original Message-----
> From: time-nuts-bounces at febo.com
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Bj?rn Gabrielsson
> Sent: Wednesday, October 22, 2008 2:23 PM
> To: time-nuts
> Subject: [time-nuts] OT: connector identification
>
> Hi List,
>
> I have a coax connector that I would like to identify. Se
> attached picture.
>
> To the left is a female TNC for reference. The unknown male
> is attached to the cable. Unknown female to the upper left as
> part of a "T" adapter.
>
> It looks kind of a smaller version of TNC. It is slighly
> larger than SMA. Female diameter is 5/16", whereas TNC is
> 7/16" and SMA is 4/16" - according to my simple measurement.
>
> Anyone recognizing this connector?
>
> thanks,
>
>     Bj?rn
>


From GandalfG8 at aol.com  Thu Oct 23 00:21:32 2008
From: GandalfG8 at aol.com (GandalfG8 at aol.com)
Date: Wed, 22 Oct 2008 20:21:32 EDT
Subject: [time-nuts] OT: connector identification
Message-ID: <c71.343513ab.36311d8c@aol.com>

 
In a message dated 23/10/2008 01:07:43 GMT Daylight Time,  
james.p.lux at jpl.nasa.gov writes:

There IS  a mini-TNC as I recall. My ancient (80s vintage) cellphone had such 
a thing on  the antenna.  There's also something referred to as a mini-UHF  
(presumably a small PL-259), but the amphenol catalog pitures show the  
serrated top of the female, and yours are smooth.  The thread was 3/8"  -24 
threads/inch




---------------
 
Yup, mini UHF is just that, and there's a mini BNC too, even a mini version  
of the original Belling-Lee TV coax connector, so mini-TNC might not be quite  
such a strange beast after all:-)
 
regards
 
Nigel
GM8PZR

From quenbob5 at pacbell.net  Thu Oct 23 01:22:18 2008
From: quenbob5 at pacbell.net (Bob Q)
Date: Wed, 22 Oct 2008 18:22:18 -0700
Subject: [time-nuts] Question on crystal jumps
References: <K95RRZ$FAF15E0C201369F08F1E9E13C34A5EF0@libero.it>
	<23695.192.25.240.225.1224710637.squirrel@webmail.sonic.net>
Message-ID: <002a01c934ad$cb5b13a0$1801a8c0@BOBCEL1R7>

Do rubidium standards use an OCXO?
Bob Q.

----- Original Message ----- 
From: "Rick Karlquist" <richard at karlquist.com>
To: "Discussion of precise time and frequency measurement" 
<time-nuts at febo.com>
Sent: Wednesday, October 22, 2008 2:23 PM
Subject: Re: [time-nuts] Question on crystal jumps


> I'm not quite sure what the question is here, but when
> we made 10811 oscillators at HP, "jumps happened".  Some
> crystals were better than others, but no crystal was immune
> from jumps.  With good quality crystals, you might be able
> to put an upper bound on the magnitude of jumps, like 10-9,
> but not on the time between jumps.  I also noticed that there
> didn't seem to be any correlation between jump activity
> and stability between jumps.  You could have an oscillator
> with really low aging, say a few parts in 1E11 per day that
> looked really good for quite a while, but then the frequency
> jumps.  After you've controlled everything you can about the
> crystal process, the electronics, the oven and the environment,
> you are still left with jumps.  If you want no jumps, go to
> an atomic standard like rubidium.  There are mechanisms that
> can cause jumps in rubidium standards as well, but good
> rubidium standards don't jump.
>
> Rick Karlquist N6RK
>
>
> iovane\@inwind\.it wrote:
>> I would be very pleased to know when (date and time) anybody
>> out there happened to record jumps in frequency of crystals.
>> I have stable (e-07) tuning forks which happen to jump too,
>> and I don't understand why, even having under control
>> temperature and air pressure. Sometimes they return to their
>> prior frequency with another jump, and this could happen even
>> days later, sometimes they jump and then recover smoothly the
>> prior frequency in a short time (such as one hour).
>> I have no idea whether any correlations would exist between
>> crystals and tuning forks jumps, regarding the causes that
>> could trigger metastability, and hence I would have a look at
>> crystal data in order to improve the base for future
>> speculation.
>>
>> Thanks in advance.
>> Antonio I8IOV
>>
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>>
>>
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there. 



From max at maxsmusicplace.com  Thu Oct 23 01:31:57 2008
From: max at maxsmusicplace.com (Max Robinson)
Date: Wed, 22 Oct 2008 20:31:57 -0500
Subject: [time-nuts] Question on crystal jumps
References: <K95RRZ$FAF15E0C201369F08F1E9E13C34A5EF0@libero.it><23695.192.25.240.225.1224710637.squirrel@webmail.sonic.net>
	<002a01c934ad$cb5b13a0$1801a8c0@BOBCEL1R7>
Message-ID: <008601c934af$23f8aa30$6401a8c0@BACKROOM>

This is a very interesting thread.  When I retired from Western Kentucky 
University in 2001 I was given a very expensive mantel clock.  Seven day 
wind up with a balance wheel.  I have had a lot of fun regulating it over 
the last 7 years.  Right now I have it holding within 5 seconds a month but 
past experience has shown that it won't hold indefinitely.  Since the 
balance wheel is also an oscillator I assume it will undergo these frequency 
jumps.

Regards.

Max.  K 4 O D S.

Email: max at maxsmusicplace.com

Transistor site http://www.funwithtransistors.net
Vacuum tube site: http://www.funwithtubes.net
Music site: http://www.maxsmusicplace.com

To subscribe to the fun with tubes group send an email to,
funwithtubes-subscribe at yahoogroups.com

----- Original Message ----- 
From: "Bob Q" <quenbob5 at pacbell.net>
To: "Discussion of precise time and frequency measurement" 
<time-nuts at febo.com>
Sent: Wednesday, October 22, 2008 8:22 PM
Subject: Re: [time-nuts] Question on crystal jumps


> Do rubidium standards use an OCXO?
> Bob Q.
>
> ----- Original Message ----- 
> From: "Rick Karlquist" <richard at karlquist.com>
> To: "Discussion of precise time and frequency measurement"
> <time-nuts at febo.com>
> Sent: Wednesday, October 22, 2008 2:23 PM
> Subject: Re: [time-nuts] Question on crystal jumps
>
>
>> I'm not quite sure what the question is here, but when
>> we made 10811 oscillators at HP, "jumps happened".  Some
>> crystals were better than others, but no crystal was immune
>> from jumps.  With good quality crystals, you might be able
>> to put an upper bound on the magnitude of jumps, like 10-9,
>> but not on the time between jumps.  I also noticed that there
>> didn't seem to be any correlation between jump activity
>> and stability between jumps.  You could have an oscillator
>> with really low aging, say a few parts in 1E11 per day that
>> looked really good for quite a while, but then the frequency
>> jumps.  After you've controlled everything you can about the
>> crystal process, the electronics, the oven and the environment,
>> you are still left with jumps.  If you want no jumps, go to
>> an atomic standard like rubidium.  There are mechanisms that
>> can cause jumps in rubidium standards as well, but good
>> rubidium standards don't jump.
>>
>> Rick Karlquist N6RK
>>
>>
>> iovane\@inwind\.it wrote:
>>> I would be very pleased to know when (date and time) anybody
>>> out there happened to record jumps in frequency of crystals.
>>> I have stable (e-07) tuning forks which happen to jump too,
>>> and I don't understand why, even having under control
>>> temperature and air pressure. Sometimes they return to their
>>> prior frequency with another jump, and this could happen even
>>> days later, sometimes they jump and then recover smoothly the
>>> prior frequency in a short time (such as one hour).
>>> I have no idea whether any correlations would exist between
>>> crystals and tuning forks jumps, regarding the causes that
>>> could trigger metastability, and hence I would have a look at
>>> crystal data in order to improve the base for future
>>> speculation.
>>>
>>> Thanks in advance.
>>> Antonio I8IOV
>>>
>>>
>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to
>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>>
>>>
>>
>>
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
> 



From rexa at sonic.net  Thu Oct 23 03:41:39 2008
From: rexa at sonic.net (Rex)
Date: Wed, 22 Oct 2008 20:41:39 -0700
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <20081022232858.13D6E1165C3@hamburg.alientech.net>
References: <K95VC3$5A93FEA5D3557405BCC98361F70C0EE3@libero.it>	<02150B5B362B4B3BB378465B54C24BB2@cyrus>
	<20081022232858.13D6E1165C3@hamburg.alientech.net>
Message-ID: <48FFF273.4080409@sonic.net>

Mike S wrote:
> At 06:48 PM 10/22/2008, Bill Hawkins wrote...
>   
>> I would not discourage you from looking for an intergalactic cause of 
>> jumps, but I think the laws of probability are quite sound.
>>     
>
> OTOH, perhaps Yoda is correct - "I feel a disturbance in the force." 
> :-)
>
>
>   

Could be like Schroedinger's Cat. If you guys would stop watching your 
clocks so closely maybe they'd stop jumping.



From hmurray at megapathdsl.net  Thu Oct 23 04:41:52 2008
From: hmurray at megapathdsl.net (Hal Murray)
Date: Wed, 22 Oct 2008 21:41:52 -0700
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: Message from "Max Robinson" <max@maxsmusicplace.com> of "Wed,
	22 Oct 2008 20:31:57 CDT." <008601c934af$23f8aa30$6401a8c0@BACKROOM> 
Message-ID: <20081023044153.CA8A6BCD4@ip-64-139-1-69.sjc.megapath.net>


> This is a very interesting thread.  When I retired from Western
> Kentucky  University in 2001 I was given a very expensive mantel
> clock.  Seven day  wind up with a balance wheel.  I have had a lot of
> fun regulating it over  the last 7 years.  Right now I have it holding
> within 5 seconds a month but  past experience has shown that it won't
> hold indefinitely.  Since the  balance wheel is also an oscillator I
> assume it will undergo these frequency  jumps. 

How small a jump could you notice?

Unless you have it in a temperature controlled box, I'd expect any tiny jumps 
would be lost in the temperature wobbles.

Can you see temperature wobbles?  Can you see any correlations with the phase 
of the moon?  (gravity, tides)



-- 
These are my opinions, not necessarily my employer's.  I hate spam.





From ian.sheffield1 at tesco.net  Thu Oct 23 07:28:19 2008
From: ian.sheffield1 at tesco.net (Ian Sheffield)
Date: Thu, 23 Oct 2008 08:28:19 +0100
Subject: [time-nuts] Question on crystal jumps
References: <20081023044153.CA8A6BCD4@ip-64-139-1-69.sjc.megapath.net>
Message-ID: <00b201c934e0$edb7e3a0$0300000a@cookie>

You probably know that the combined effects of the Moon and Sun changes the 
rate of a pendulum clock by up to 1 part in 10 to the 7th, but that is a 
smooth sine rather than a jump. That shouldn't affect quartz either.

I agree with other posters - you are probably seeing the quantization of 
space/time ;-)

Ian.

----- Original Message ----- 
From: "Hal Murray" <hmurray at megapathdsl.net>
To: "Discussion of precise time and frequency measurement" 
<time-nuts at febo.com>
Sent: Thursday, October 23, 2008 5:41 AM
Subject: Re: [time-nuts] Question on crystal jumps


>
>> This is a very interesting thread.  When I retired from Western
>> Kentucky  University in 2001 I was given a very expensive mantel
>> clock.  Seven day  wind up with a balance wheel.  I have had a lot of
>> fun regulating it over  the last 7 years.  Right now I have it holding
>> within 5 seconds a month but  past experience has shown that it won't
>> hold indefinitely.  Since the  balance wheel is also an oscillator I
>> assume it will undergo these frequency  jumps.
>
> How small a jump could you notice?
>
> Unless you have it in a temperature controlled box, I'd expect any tiny 
> jumps
> would be lost in the temperature wobbles.
>
> Can you see temperature wobbles?  Can you see any correlations with the 
> phase
> of the moon?  (gravity, tides)
>
>
>
> -- 
> These are my opinions, not necessarily my employer's.  I hate spam.
>
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.


--------------------------------------------------------------------------------



No virus found in this incoming message.
Checked by AVG - http://www.avg.com
Version: 8.0.175 / Virus Database: 270.8.2/1739 - Release Date: 10/22/2008 
07:23



From jherrero at hvsistemas.es  Thu Oct 23 08:19:40 2008
From: jherrero at hvsistemas.es (Javier Herrero)
Date: Thu, 23 Oct 2008 10:19:40 +0200
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <48FFF273.4080409@sonic.net>
References: <K95VC3$5A93FEA5D3557405BCC98361F70C0EE3@libero.it>	<02150B5B362B4B3BB378465B54C24BB2@cyrus>	<20081022232858.13D6E1165C3@hamburg.alientech.net>
	<48FFF273.4080409@sonic.net>
Message-ID: <4900339C.8010200@hvsistemas.es>

Rex escribi?:
>>
>> OTOH, perhaps Yoda is correct - "I feel a disturbance in the force." 
>> :-)
>>
>>
>>   
>
> Could be like Schroedinger's Cat. If you guys would stop watching your 
> clocks so closely maybe they'd stop jumping.
>
Or not... or only half jumping (not the same that jumping the half ;) )

-- 
------------------------------------------------------------------------
Javier Herrero                            EMAIL: jherrero at hvsistemas.com
HV Sistemas S.L.                          PHONE:         +34 949 336 806
Los Charcones, 17A                        FAX:           +34 949 336 792
19170 El Casar - Guadalajara - Spain      WEB: http://www.hvsistemas.com



From bg at lysator.liu.se  Thu Oct 23 08:43:31 2008
From: bg at lysator.liu.se (=?ISO-8859-1?Q?Bj=F6rn?= Gabrielsson)
Date: Thu, 23 Oct 2008 10:43:31 +0200
Subject: [time-nuts] OT: connector identification
In-Reply-To: <1224714343.6071.39.camel@bg-desktop>
References: <1224710605.6071.28.camel@bg-desktop>
	<48FFA26F.2040803@bellsouth.net> <1224714343.6071.39.camel@bg-desktop>
Message-ID: <1224751411.10741.13.camel@bg-desktop>

Thanks everyone,

The connector is called TM and was manufactured by Solitron Microwave. 

TM is not the ideal name to google for... Maybe TM IS short for TNC
mini... 

Here is someone looking for adaptors recently.

http://sci.tech-archive.net/Archive/sci.electronics.components/2008-08/msg00066.html

Here is someone with some old stock. (The Tee is PN 3072-0001)

    http://www.rfdepot.com/M0095.HTML

--

   Bj?rn

On Thu, 2008-10-23 at 00:25 +0200, Bj?rn Gabrielsson wrote:
> Brian,
> 
> No its not an SMC. See attached photo. 
> 
> >From the left,
> 
> male and female SMA, female and male unkown and to the right the smaller
> male SMC.
> 
> --
> 
>    Bj?rn
> 
> On Wed, 2008-10-22 at 17:00 -0500, Brian Kirby wrote:
> > It may be SMC now that I looked it up.  A connector guide is attached....
> > 
> > 
> > Bj?rn Gabrielsson wrote:
> > > Hi List,
> > > 
> > > I have a coax connector that I would like to identify. Se attached
> > > picture. 
> > > 
> > > To the left is a female TNC for reference. The unknown male is attached
> > > to the cable. Unknown female to the upper left as part of a "T" adapter.
> > > 
> > > It looks kind of a smaller version of TNC. It is slighly larger than
> > > SMA. Female diameter is 5/16", whereas TNC is 7/16" and SMA is 4/16" -
> > > according to my simple measurement.
> > > 
> > > Anyone recognizing this connector?
> > > 
> > > thanks,
> > > 
> > >     Bj?rn
> > > 
> > > 
> > > ------------------------------------------------------------------------
> > > 
> > > 
> > > ------------------------------------------------------------------------
> > > 
> > > _______________________________________________
> > > time-nuts mailing list -- time-nuts at febo.com
> > > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > > and follow the instructions there.
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.



From sar10538 at gmail.com  Thu Oct 23 10:35:37 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Thu, 23 Oct 2008 23:35:37 +1300
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <002401c9349b$29ef1780$4201a8c0@G3SVW>
References: <K95UQ4$48083C91C65FA4E4C6B80E1A7FAAEC4F@libero.it>
	<002401c9349b$29ef1780$4201a8c0@G3SVW>
Message-ID: <1231b6a80810230335r74a6bf27r5e9db838425d0364@mail.gmail.com>

2008/10/23 Ron Smith <ronald.p.smith at btinternet.com>:
> The text says the curve of frequency against plate thickness does not give a
> straight line, but has discontinuities in it. These discontinuities they
> call "stepping points" and are a result of edge vibrations coinciding with
> sub-multiple frequencies of the wanted thickness vibration mode. The degree
> of coupling between the wanted and unwanted modes varies with crystal
> dimension. If there is zero coupling, the stepping points should not affect
> the main oscillation. But perhaps even the smallest change in dimension can
> cause it to cross one of these discontinuities and jump to and fro? I
> suspect that crystal sensitivity to stepping or jumping may be correlated
> with its temperature coefficient, although there are other factors
> (including gravitational) that influence frequency of oscillation at very
> small levels.

I have a counter that seems to exhibit a jump in it's timebase. From a
cold state a fixed frequency connected to the input shows a gradual
change as the unit heats up over an hour or two. Once it reaches a
stable state it will stay in that state for a couple of days and then
it will jump to a new stable state, and stay in that state however
long the unit is switched on. This is repeatable each time I switch
on. I have not observed the jump and there is no data output on the
counter to be able to record the times that this happens. All I know
is that there is a definite little jump after a long period of
stability.

73 - Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From wb6bnq at cox.net  Thu Oct 23 10:42:42 2008
From: wb6bnq at cox.net (WB6BNQ)
Date: Thu, 23 Oct 2008 03:42:42 -0700
Subject: [time-nuts] Question on crystal jumps
References: <K95RRZ$FAF15E0C201369F08F1E9E13C34A5EF0@libero.it>
	<23695.192.25.240.225.1224710637.squirrel@webmail.sonic.net>
	<002a01c934ad$cb5b13a0$1801a8c0@BOBCEL1R7>
Message-ID: <49005522.FAE46EB7@cox.net>

Hi Bob Q,

Yes Rubidium (Rb) and Cesium (Cs) standards use OCXO's.

I suppose the way to look at it is the Rb or Cs chamber acts as an
invariant
atomic filter with extremely narrow bandpass (i.e., with an extremely
high Q).
The resonant frequencies of these atomic filters are up in the microwave
regions
and thus do not lend themselves easily to direct comparison.  So, a high
quality
standard frequency oscillator is locked in a loop controlled by the
atomic
filter.  The OCXO's output is the reference signal out of the atomic
standard.

I hope this rather simplistic overview answers your question ?

Bill....WB6BNQ

Bob Q wrote:

> Do rubidium standards use an OCXO?
> Bob Q.
>
> ----- Original Message -----
> From: "Rick Karlquist" <richard at karlquist.com>
> To: "Discussion of precise time and frequency measurement"
> <time-nuts at febo.com>
> Sent: Wednesday, October 22, 2008 2:23 PM
> Subject: Re: [time-nuts] Question on crystal jumps
>
> > I'm not quite sure what the question is here, but when
> > we made 10811 oscillators at HP, "jumps happened".  Some
> > crystals were better than others, but no crystal was immune
> > from jumps.  With good quality crystals, you might be able
> > to put an upper bound on the magnitude of jumps, like 10-9,
> > but not on the time between jumps.  I also noticed that there
> > didn't seem to be any correlation between jump activity
> > and stability between jumps.  You could have an oscillator
> > with really low aging, say a few parts in 1E11 per day that
> > looked really good for quite a while, but then the frequency
> > jumps.  After you've controlled everything you can about the
> > crystal process, the electronics, the oven and the environment,
> > you are still left with jumps.  If you want no jumps, go to
> > an atomic standard like rubidium.  There are mechanisms that
> > can cause jumps in rubidium standards as well, but good
> > rubidium standards don't jump.
> >
> > Rick Karlquist N6RK
> >
> >
> > iovane\@inwind\.it wrote:
> >> I would be very pleased to know when (date and time) anybody
> >> out there happened to record jumps in frequency of crystals.
> >> I have stable (e-07) tuning forks which happen to jump too,
> >> and I don't understand why, even having under control
> >> temperature and air pressure. Sometimes they return to their
> >> prior frequency with another jump, and this could happen even
> >> days later, sometimes they jump and then recover smoothly the
> >> prior frequency in a short time (such as one hour).
> >> I have no idea whether any correlations would exist between
> >> crystals and tuning forks jumps, regarding the causes that
> >> could trigger metastability, and hence I would have a look at
> >> crystal data in order to improve the base for future
> >> speculation.
> >>
> >> Thanks in advance.
> >> Antonio I8IOV
> >>
> >>
> >>
> >> _______________________________________________
> >> time-nuts mailing list -- time-nuts at febo.com
> >> To unsubscribe, go to
> >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> >> and follow the instructions there.
> >>
> >>
> >
> >
> >
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at febo.com
> > To unsubscribe, go to
> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.


From namichie at gmail.com  Thu Oct 23 11:00:56 2008
From: namichie at gmail.com (Neville Michie)
Date: Thu, 23 Oct 2008 22:00:56 +1100
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <49005522.FAE46EB7@cox.net>
References: <K95RRZ$FAF15E0C201369F08F1E9E13C34A5EF0@libero.it>
	<23695.192.25.240.225.1224710637.squirrel@webmail.sonic.net>
	<002a01c934ad$cb5b13a0$1801a8c0@BOBCEL1R7>
	<49005522.FAE46EB7@cox.net>
Message-ID: <5308066F-31D8-4F19-80D9-66BA4E628364@gmail.com>

Hi,
The EFRATOM LPRO does not use a OCXO, just a straight quartz crystal  
oscillator.
The control voltage swings around a volt as the base plate warms up.
The time constant of the PLL that the XO is in must be quite short, a  
small fraction of a second
so that the effect of drifting temperature has little effect on the  
output.
I guess that all the crystal does is to filter what must be a quite  
noisy signal
from the atomic resonance. When I inspected the circuit board I could  
not even find the crystal,
it is not in a grand crystal can.
cheers, Neville Michie


On 23/10/2008, at 9:42 PM, WB6BNQ wrote:

> Hi Bob Q,
>
> Yes Rubidium (Rb) and Cesium (Cs) standards use OCXO's.
>
> I suppose the way to look at it is the Rb or Cs chamber acts as an
> invariant
> atomic filter with extremely narrow bandpass (i.e., with an extremely
> high Q).
> The resonant frequencies of these atomic filters are up in the  
> microwave
> regions
> and thus do not lend themselves easily to direct comparison.  So, a  
> high
> quality
> standard frequency oscillator is locked in a loop controlled by the
> atomic
> filter.  The OCXO's output is the reference signal out of the atomic
> standard.
>
> I hope this rather simplistic overview answers your question ?
>
> Bill....WB6BNQ
>
> Bob Q wrote:
>
>> Do rubidium standards use an OCXO?
>> Bob Q.
>>
>> ----- Original Message -----
>> From: "Rick Karlquist" <richard at karlquist.com>
>> To: "Discussion of precise time and frequency measurement"
>> <time-nuts at febo.com>
>> Sent: Wednesday, October 22, 2008 2:23 PM
>> Subject: Re: [time-nuts] Question on crystal jumps
>>
>>> I'm not quite sure what the question is here, but when
>>> we made 10811 oscillators at HP, "jumps happened".  Some
>>> crystals were better than others, but no crystal was immune
>>> from jumps.  With good quality crystals, you might be able
>>> to put an upper bound on the magnitude of jumps, like 10-9,
>>> but not on the time between jumps.  I also noticed that there
>>> didn't seem to be any correlation between jump activity
>>> and stability between jumps.  You could have an oscillator
>>> with really low aging, say a few parts in 1E11 per day that
>>> looked really good for quite a while, but then the frequency
>>> jumps.  After you've controlled everything you can about the
>>> crystal process, the electronics, the oven and the environment,
>>> you are still left with jumps.  If you want no jumps, go to
>>> an atomic standard like rubidium.  There are mechanisms that
>>> can cause jumps in rubidium standards as well, but good
>>> rubidium standards don't jump.
>>>
>>> Rick Karlquist N6RK
>>>
>>>
>>> iovane\@inwind\.it wrote:
>>>> I would be very pleased to know when (date and time) anybody
>>>> out there happened to record jumps in frequency of crystals.
>>>> I have stable (e-07) tuning forks which happen to jump too,
>>>> and I don't understand why, even having under control
>>>> temperature and air pressure. Sometimes they return to their
>>>> prior frequency with another jump, and this could happen even
>>>> days later, sometimes they jump and then recover smoothly the
>>>> prior frequency in a short time (such as one hour).
>>>> I have no idea whether any correlations would exist between
>>>> crystals and tuning forks jumps, regarding the causes that
>>>> could trigger metastability, and hence I would have a look at
>>>> crystal data in order to improve the base for future
>>>> speculation.
>>>>
>>>> Thanks in advance.
>>>> Antonio I8IOV
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> time-nuts mailing list -- time-nuts at febo.com
>>>> To unsubscribe, go to
>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>>> and follow the instructions there.
>>>>
>>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to
>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>> and follow the instructions there.
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/ 
>> listinfo/time-nuts
>> and follow the instructions there.
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ 
> time-nuts
> and follow the instructions there.



From cdreher at sta.samsung.com  Thu Oct 23 14:12:16 2008
From: cdreher at sta.samsung.com (Carl Dreher)
Date: Thu, 23 Oct 2008 09:12:16 -0500
Subject: [time-nuts] time-nuts Digest, Vol 51, Issue 71
In-Reply-To: <mailman.88.1224720332.2539.time-nuts@febo.com>
References: <mailman.88.1224720332.2539.time-nuts@febo.com>
Message-ID: <64260ABC228BC44AA5A9BE082AF4AAB602235C98@mx2.telecom.sna.samsung.com>

Hi,
This is my first input to the list.

From bogus@does.not.exist.com  Fri Oct 17 00:59:29 2008
From: bogus@does.not.exist.com ()
Date: Fri, 17 Oct 2008 00:59:29 -0000
Subject: No subject
Message-ID: <mailman.2.1224773050.2536.time-nuts@febo.com>

change in the rod length.  This has actually been measured, and is
accredited to crystal lattice slippage of the material.  This has been
found in metal and recently, crystal rod pendulum.  It is significant in
the latter because experimenters went to crystal rods for their
temperance invariance, only to find the unpredictable spontaneous length
change.

Carl Dreher
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
In : Accurate Clock Pendulums by Robert Matthys (2004) Oxford =20
University Press ISBN 0198529716, Pp264
In Chapter 8 , "The Allen variance and the rms time error", on page 38
he writes:
Figure 8.1 shows another characteristic of pendulum clocks - the =20
clock will run relatively
smoothly at one rate , and then after 3 - 6 months it will suddenly =20
jump to a new rate
as shown if Fig 8.1.

He goes on to say that this is part of a random walk process.

I hope that is of some help.
Neville MIchie


From shoppa at trailing-edge.com  Thu Oct 23 15:09:15 2008
From: shoppa at trailing-edge.com (Tim Shoppa)
Date: Thu, 23 Oct 2008 11:09:15 -0400
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <K95UQ4$48083C91C65FA4E4C6B80E1A7FAAEC4F@libero.it>
References: <K95UQ4$48083C91C65FA4E4C6B80E1A7FAAEC4F@libero.it>
Message-ID: <20081023150915.E5DECBA4D14@mini-me.trailing-edge.com>

"iovane\@inwind\.it" <iovane at inwind.it> wrote:
> Hi Rick
>
> > I'm not quite sure what the question is here....
> > ....
>
> The question is:
> may anybody tell me (date and time) when a crystal jumped?
> (a sample response could be: my crystal jumped on January 22, 2006 12:25 UT).
>
> I would like to map in time as many jumps as possible.
>
> I hope someone in the list has a log of his jumps.
>
> Thanks and 73,
> Antonio I8IOV

Antonio -

Folks have short (days) and long (multi-year) plots of the EFC in their
Z3801A. The EFC is the correction factor to keep the 10811 inside
phase-locked with GPS. At www.realhamradio.com you'll see an index
of many many people's EFC plots.

My unit shows a fairly steady aging drift with random EFC jumps, typically
once or twice a week, but sometimes it goes weeks between jumps.

My gut feeling is that the distribution of times between jumps
is Poisson, but only because I'm a former nuclear physicist :-).

Tim.


From quenbob5 at pacbell.net  Thu Oct 23 15:36:11 2008
From: quenbob5 at pacbell.net (Bob Q)
Date: Thu, 23 Oct 2008 08:36:11 -0700
Subject: [time-nuts] Question on crystal jumps
References: <K95RRZ$FAF15E0C201369F08F1E9E13C34A5EF0@libero.it><23695.192.25.240.225.1224710637.squirrel@webmail.sonic.net><002a01c934ad$cb5b13a0$1801a8c0@BOBCEL1R7>
	<49005522.FAE46EB7@cox.net>
Message-ID: <000f01c93525$14745480$1801a8c0@BOBCEL1R7>

So why would they not show the same kind of jumps as plain OCXO's?  Rick K. 
mentioned atomic standards avoid jumps.
Bob Q.
----- Original Message ----- 
From: "WB6BNQ" <wb6bnq at cox.net>
To: "Discussion of precise time and frequency measurement" 
<time-nuts at febo.com>
Sent: Thursday, October 23, 2008 3:42 AM
Subject: Re: [time-nuts] Question on crystal jumps


> Hi Bob Q,
>
> Yes Rubidium (Rb) and Cesium (Cs) standards use OCXO's.
>
> I suppose the way to look at it is the Rb or Cs chamber acts as an
> invariant
> atomic filter with extremely narrow bandpass (i.e., with an extremely
> high Q).
> The resonant frequencies of these atomic filters are up in the microwave
> regions
> and thus do not lend themselves easily to direct comparison.  So, a high
> quality
> standard frequency oscillator is locked in a loop controlled by the
> atomic
> filter.  The OCXO's output is the reference signal out of the atomic
> standard.
>
> I hope this rather simplistic overview answers your question ?
>
> Bill....WB6BNQ
>
> Bob Q wrote:
>
>> Do rubidium standards use an OCXO?
>> Bob Q.
>>
>> ----- Original Message -----
>> From: "Rick Karlquist" <richard at karlquist.com>
>> To: "Discussion of precise time and frequency measurement"
>> <time-nuts at febo.com>
>> Sent: Wednesday, October 22, 2008 2:23 PM
>> Subject: Re: [time-nuts] Question on crystal jumps
>>
>> > I'm not quite sure what the question is here, but when
>> > we made 10811 oscillators at HP, "jumps happened".  Some
>> > crystals were better than others, but no crystal was immune
>> > from jumps.  With good quality crystals, you might be able
>> > to put an upper bound on the magnitude of jumps, like 10-9,
>> > but not on the time between jumps.  I also noticed that there
>> > didn't seem to be any correlation between jump activity
>> > and stability between jumps.  You could have an oscillator
>> > with really low aging, say a few parts in 1E11 per day that
>> > looked really good for quite a while, but then the frequency
>> > jumps.  After you've controlled everything you can about the
>> > crystal process, the electronics, the oven and the environment,
>> > you are still left with jumps.  If you want no jumps, go to
>> > an atomic standard like rubidium.  There are mechanisms that
>> > can cause jumps in rubidium standards as well, but good
>> > rubidium standards don't jump.
>> >
>> > Rick Karlquist N6RK
>> >
>> >
>> > iovane\@inwind\.it wrote:
>> >> I would be very pleased to know when (date and time) anybody
>> >> out there happened to record jumps in frequency of crystals.
>> >> I have stable (e-07) tuning forks which happen to jump too,
>> >> and I don't understand why, even having under control
>> >> temperature and air pressure. Sometimes they return to their
>> >> prior frequency with another jump, and this could happen even
>> >> days later, sometimes they jump and then recover smoothly the
>> >> prior frequency in a short time (such as one hour).
>> >> I have no idea whether any correlations would exist between
>> >> crystals and tuning forks jumps, regarding the causes that
>> >> could trigger metastability, and hence I would have a look at
>> >> crystal data in order to improve the base for future
>> >> speculation.
>> >>
>> >> Thanks in advance.
>> >> Antonio I8IOV
>> >>
>> >>
>> >>
>> >> _______________________________________________
>> >> time-nuts mailing list -- time-nuts at febo.com
>> >> To unsubscribe, go to
>> >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> >> and follow the instructions there.
>> >>
>> >>
>> >
>> >
>> >
>> > _______________________________________________
>> > time-nuts mailing list -- time-nuts at febo.com
>> > To unsubscribe, go to
>> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> > and follow the instructions there.
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to 
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there. 



From brooke at pacific.net  Thu Oct 23 16:24:36 2008
From: brooke at pacific.net (Brooke Clarke)
Date: Thu, 23 Oct 2008 09:24:36 -0700
Subject: [time-nuts] jump in pendulum clocks
In-Reply-To: <64260ABC228BC44AA5A9BE082AF4AAB602235C98@mx2.telecom.sna.samsung.com>
References: <mailman.88.1224720332.2539.time-nuts@febo.com>
	<64260ABC228BC44AA5A9BE082AF4AAB602235C98@mx2.telecom.sna.samsung.com>
Message-ID: <4900A544.5090103@pacific.net>

Hi Carl:

That's interesting.  After reading Accurate Clock Pendulums and a number of 
other books then researching patents I found:

3036465 Gravity Meter, Robert H. Dicke, May 29, 1962, 73/382R ; 73/514.29
 >= 20 cps, Q >1,000,000 optical pick up and electrostatic drive, mostly fused 
quartz parts.  He also invented the lock-in-amplifier and Dicke radiometer.
http://www.prc68.com/I/Pendulums.shtml

It's almost all quartz, but now I see why they are not more popular.

Have Fun,

Brooke Clarke
http://www.prc68.com/P/Prod.html  Products I make and sell
http://www.prc68.com/Alpha.shtml  All my web pages listed based on html name
http://www.PRC68.com
http://www.precisionclock.com
http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Web Cam

Carl Dreher wrote:
> Hi,
> This is my first input to the list.
>>From what I've read, the jump in pendulum clocks is due to a spontaneous
> change in the rod length.  This has actually been measured, and is
> accredited to crystal lattice slippage of the material.  This has been
> found in metal and recently, crystal rod pendulum.  It is significant in
> the latter because experimenters went to crystal rods for their
> temperance invariance, only to find the unpredictable spontaneous length
> change.
> 
> Carl Dreher
> ==============
> In : Accurate Clock Pendulums by Robert Matthys (2004) Oxford  
> University Press ISBN 0198529716, Pp264
> In Chapter 8 , "The Allen variance and the rms time error", on page 38
> he writes:
> Figure 8.1 shows another characteristic of pendulum clocks - the  
> clock will run relatively
> smoothly at one rate , and then after 3 - 6 months it will suddenly  
> jump to a new rate
> as shown if Fig 8.1.
> 
> He goes on to say that this is part of a random walk process.
> 
> I hope that is of some help.
> Neville MIchie
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 


From SAIDJACK at aol.com  Thu Oct 23 16:25:44 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Thu, 23 Oct 2008 12:25:44 EDT
Subject: [time-nuts] Question on crystal jumps
Message-ID: <cc9.3f79d9e1.3631ff88@aol.com>

Hi Bob,
 
they should and do, and if it jumps the Rb will pull-in the OCXO  frequency 
correcting for the error. This pull in time is determined by the loop  time 
(cut-off frequency) of the Rb PLL loop. I expect this loop time to be much  
shorter than a GPSDO's loop time, so the effect is probably much less visible.  One 
should still be able to see it as a distinct offset when plotting the  EFC 
control voltage of the OCXO.
 
Considering that jumps often hit 1ppb offset, I am surprised how many folks  
on this forum have discussed that their oscillators jump, and how little  
research actually has gone into figuring out how to minimize these jumps. I  would 
not be a big fan of contraptions that use two or three OCXO's to minimize  
the impact since all three could potentially jump at the same time. I would  
rather attack the problem at the source - most of the time its the  crystal.
 
There is probably something that can be done to minimize jumps, such as the  
crystal cut, modifying the crystal operating temperature, modifying the 
current  through the crystal, comparing different mounting methods, changing the  
direction (orientation) the crystal is mounted in, etc etc.
 
Here is a hint for experimentation: I once had an OCXO that jumped all the  
time (many times per hour). Since this was a reject part (definitely a factory  
RMA), I took a large screwdriver and gave the OCXO a good bang. The jumping 
was  immediately mitigated down to a couple of times per day. That causality 
was a  real eye opener, whatever stresses were on the crystal were released by 
the  shock.
 
bye,
Said 
 
 
In a message dated 10/23/2008 08:39:18 Pacific Daylight Time,  
quenbob5 at pacbell.net writes:

So why  would they not show the same kind of jumps as plain OCXO's?  Rick K.  
mentioned atomic standards avoid jumps.
Bob  Q.


From brooke at pacific.net  Thu Oct 23 16:49:27 2008
From: brooke at pacific.net (Brooke Clarke)
Date: Thu, 23 Oct 2008 09:49:27 -0700
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <cc9.3f79d9e1.3631ff88@aol.com>
References: <cc9.3f79d9e1.3631ff88@aol.com>
Message-ID: <4900AB17.8000700@pacific.net>

Hi Said:

All kinds of things effect the crystal including gravity.  Some time ago I 
wrote a Labview program to look at the control voltage then rotated the PRS10 
resting it on each of four faces, see:
http://www.prc68.com/I/Images/FC_ROT.jpg
So, just as gravity effects pendulum clocks, it's also effecting crystal 
oscillators, just on a smaller scale.

There also was a LV screen for the physics package, see:
http://www.prc68.com/I/Images/Phy.jpg

The PRS10 is at:
http://www.prc68.com/I/PRS10.shtml

Have Fun,

Brooke Clarke
http://www.prc68.com/P/Prod.html  Products I make and sell
http://www.prc68.com/Alpha.shtml  All my web pages listed based on html name
http://www.PRC68.com
http://www.precisionclock.com
http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Web Cam

SAIDJACK at aol.com wrote:
> Hi Bob,
>  
> they should and do, and if it jumps the Rb will pull-in the OCXO  frequency 
> correcting for the error. This pull in time is determined by the loop  time 
> (cut-off frequency) of the Rb PLL loop. I expect this loop time to be much  
> shorter than a GPSDO's loop time, so the effect is probably much less visible.  One 
> should still be able to see it as a distinct offset when plotting the  EFC 
> control voltage of the OCXO.
>  
> Considering that jumps often hit 1ppb offset, I am surprised how many folks  
> on this forum have discussed that their oscillators jump, and how little  
> research actually has gone into figuring out how to minimize these jumps. I  would 
> not be a big fan of contraptions that use two or three OCXO's to minimize  
> the impact since all three could potentially jump at the same time. I would  
> rather attack the problem at the source - most of the time its the  crystal.
>  
> There is probably something that can be done to minimize jumps, such as the  
> crystal cut, modifying the crystal operating temperature, modifying the 
> current  through the crystal, comparing different mounting methods, changing the  
> direction (orientation) the crystal is mounted in, etc etc.
>  
> Here is a hint for experimentation: I once had an OCXO that jumped all the  
> time (many times per hour). Since this was a reject part (definitely a factory  
> RMA), I took a large screwdriver and gave the OCXO a good bang. The jumping 
> was  immediately mitigated down to a couple of times per day. That causality 
> was a  real eye opener, whatever stresses were on the crystal were released by 
> the  shock.
>  
> bye,
> Said 
>  
>  
> In a message dated 10/23/2008 08:39:18 Pacific Daylight Time,  
> quenbob5 at pacbell.net writes:
> 
> So why  would they not show the same kind of jumps as plain OCXO's?  Rick K.  
> mentioned atomic standards avoid jumps.
> Bob  Q.
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 


From Stefan.Heinzmann at alcnetworx.de  Thu Oct 23 17:11:50 2008
From: Stefan.Heinzmann at alcnetworx.de (Heinzmann, Stefan  (ALC NetworX GmbH))
Date: Thu, 23 Oct 2008 19:11:50 +0200
Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
Message-ID: <D7B1B5F4F3F27A4CB073BF422331203F0DD74642DD@Exchange1.lawo.de>

Hi all,

I hope you can clear up some confusion that I have regarding ADEV measurement. I was under the impression that you need a counter that is able to timestamp each rising edge of the clock under test, or equivalently measure period time continuously with no dead time. Now, while the CNT-90 can do this, the CNT-81 ( = PM6681 ) can't. Still, a message last December to the list here (http://www.mail-archive.com/time-nuts at febo.com/msg10963.html) seems to indicate that using TimeView you can have ADEV plotted with the "lesser" model, too. I have a PM6681 and TimeView, but I couldn't find out how to do it. Maybe it can't be done.

So what's the deal on this? Can it be done, with or without TimeView, and if yes, how? If this has been answered earlier, a link would be just fine.

Thanks and cheers
Stefan


From SAIDJACK at aol.com  Thu Oct 23 18:29:45 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Thu, 23 Oct 2008 14:29:45 EDT
Subject: [time-nuts] Question on crystal jumps
Message-ID: <cc1.46e0b0aa.36321c99@aol.com>

Nice plots Brooke,
 
you can see the immediate loop compensation for the g-sensitivity. These  EFC 
steps are similar to what crystal jumps would look like.
 
The question is: does the probability of seeing jumps on an OCXO  change with 
the rotation/orientation of the OCXO. I suspect it does have some  effect.
 
bye,
Said
 
 
In a message dated 10/23/2008 09:56:53 Pacific Daylight Time,  
brooke at pacific.net writes:

All  kinds of things effect the crystal including gravity.  Some time ago I  
wrote a Labview program to look at the control voltage then rotated the  
PRS10 
resting it on each of four faces,  see:
http://www.prc68.com/I/Images/FC_ROT.jpg
So, just as gravity  effects pendulum clocks, it's also effecting crystal 
oscillators, just on  a smaller scale.



From ronaldheld at gmail.com  Thu Oct 23 19:44:02 2008
From: ronaldheld at gmail.com (Ronald Held)
Date: Thu, 23 Oct 2008 15:44:02 -0400
Subject: [time-nuts] time-nuts Digest, Vol 51, Issue 73
In-Reply-To: <mailman.5.1224763201.32459.time-nuts@febo.com>
References: <mailman.5.1224763201.32459.time-nuts@febo.com>
Message-ID: <9a86fb0e0810231244s6583a23blacd0a75b94527b20@mail.gmail.com>

This may be too simplistic, but are the jumps due to aging effects?

On Thu, Oct 23, 2008 at 8:00 AM,  <time-nuts-request at febo.com> wrote:
> Send time-nuts mailing list submissions to
>        time-nuts at febo.com
>
> To subscribe or unsubscribe via the World Wide Web, visit
>        https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> or, via email, send a message with subject or body 'help' to
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>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of time-nuts digest..."
>
>
> Today's Topics:
>
>   1. Re: Question on crystal jumps (Steve Rooke)
>   2. Re: Question on crystal jumps (WB6BNQ)
>   3. Re: Question on crystal jumps (Neville Michie)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Thu, 23 Oct 2008 23:35:37 +1300
> From: "Steve Rooke" <sar10538 at gmail.com>
> Subject: Re: [time-nuts] Question on crystal jumps
> To: "Discussion of precise time and frequency measurement"
>        <time-nuts at febo.com>
> Message-ID:
>        <1231b6a80810230335r74a6bf27r5e9db838425d0364 at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> 2008/10/23 Ron Smith <ronald.p.smith at btinternet.com>:
>> The text says the curve of frequency against plate thickness does not give a
>> straight line, but has discontinuities in it. These discontinuities they
>> call "stepping points" and are a result of edge vibrations coinciding with
>> sub-multiple frequencies of the wanted thickness vibration mode. The degree
>> of coupling between the wanted and unwanted modes varies with crystal
>> dimension. If there is zero coupling, the stepping points should not affect
>> the main oscillation. But perhaps even the smallest change in dimension can
>> cause it to cross one of these discontinuities and jump to and fro? I
>> suspect that crystal sensitivity to stepping or jumping may be correlated
>> with its temperature coefficient, although there are other factors
>> (including gravitational) that influence frequency of oscillation at very
>> small levels.
>
> I have a counter that seems to exhibit a jump in it's timebase. From a
> cold state a fixed frequency connected to the input shows a gradual
> change as the unit heats up over an hour or two. Once it reaches a
> stable state it will stay in that state for a couple of days and then
> it will jump to a new stable state, and stay in that state however
> long the unit is switched on. This is repeatable each time I switch
> on. I have not observed the jump and there is no data output on the
> counter to be able to record the times that this happens. All I know
> is that there is a definite little jump after a long period of
> stability.
>
> 73 - Steve
> --
> Steve Rooke - ZL3TUV & G8KVD
> Omnium finis imminet
>
>
>
> ------------------------------
>
> Message: 2
> Date: Thu, 23 Oct 2008 03:42:42 -0700
> From: WB6BNQ <wb6bnq at cox.net>
> Subject: Re: [time-nuts] Question on crystal jumps
> To: Discussion of precise time and frequency measurement
>        <time-nuts at febo.com>
> Message-ID: <49005522.FAE46EB7 at cox.net>
> Content-Type: text/plain; charset=us-ascii
>
> Hi Bob Q,
>
> Yes Rubidium (Rb) and Cesium (Cs) standards use OCXO's.
>
> I suppose the way to look at it is the Rb or Cs chamber acts as an
> invariant
> atomic filter with extremely narrow bandpass (i.e., with an extremely
> high Q).
> The resonant frequencies of these atomic filters are up in the microwave
> regions
> and thus do not lend themselves easily to direct comparison.  So, a high
> quality
> standard frequency oscillator is locked in a loop controlled by the
> atomic
> filter.  The OCXO's output is the reference signal out of the atomic
> standard.
>
> I hope this rather simplistic overview answers your question ?
>
> Bill....WB6BNQ
>
> Bob Q wrote:
>
>> Do rubidium standards use an OCXO?
>> Bob Q.
>>
>> ----- Original Message -----
>> From: "Rick Karlquist" <richard at karlquist.com>
>> To: "Discussion of precise time and frequency measurement"
>> <time-nuts at febo.com>
>> Sent: Wednesday, October 22, 2008 2:23 PM
>> Subject: Re: [time-nuts] Question on crystal jumps
>>
>> > I'm not quite sure what the question is here, but when
>> > we made 10811 oscillators at HP, "jumps happened".  Some
>> > crystals were better than others, but no crystal was immune
>> > from jumps.  With good quality crystals, you might be able
>> > to put an upper bound on the magnitude of jumps, like 10-9,
>> > but not on the time between jumps.  I also noticed that there
>> > didn't seem to be any correlation between jump activity
>> > and stability between jumps.  You could have an oscillator
>> > with really low aging, say a few parts in 1E11 per day that
>> > looked really good for quite a while, but then the frequency
>> > jumps.  After you've controlled everything you can about the
>> > crystal process, the electronics, the oven and the environment,
>> > you are still left with jumps.  If you want no jumps, go to
>> > an atomic standard like rubidium.  There are mechanisms that
>> > can cause jumps in rubidium standards as well, but good
>> > rubidium standards don't jump.
>> >
>> > Rick Karlquist N6RK
>> >
>> >
>> > iovane\@inwind\.it wrote:
>> >> I would be very pleased to know when (date and time) anybody
>> >> out there happened to record jumps in frequency of crystals.
>> >> I have stable (e-07) tuning forks which happen to jump too,
>> >> and I don't understand why, even having under control
>> >> temperature and air pressure. Sometimes they return to their
>> >> prior frequency with another jump, and this could happen even
>> >> days later, sometimes they jump and then recover smoothly the
>> >> prior frequency in a short time (such as one hour).
>> >> I have no idea whether any correlations would exist between
>> >> crystals and tuning forks jumps, regarding the causes that
>> >> could trigger metastability, and hence I would have a look at
>> >> crystal data in order to improve the base for future
>> >> speculation.
>> >>
>> >> Thanks in advance.
>> >> Antonio I8IOV
>> >>
>> >>
>> >>
>> >> _______________________________________________
>> >> time-nuts mailing list -- time-nuts at febo.com
>> >> To unsubscribe, go to
>> >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> >> and follow the instructions there.
>> >>
>> >>
>> >
>> >
>> >
>> > _______________________________________________
>> > time-nuts mailing list -- time-nuts at febo.com
>> > To unsubscribe, go to
>> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> > and follow the instructions there.
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>
>
>
> ------------------------------
>
> Message: 3
> Date: Thu, 23 Oct 2008 22:00:56 +1100
> From: Neville Michie <namichie at gmail.com>
> Subject: Re: [time-nuts] Question on crystal jumps
> To: Discussion of precise time and frequency measurement
>        <time-nuts at febo.com>
> Message-ID: <5308066F-31D8-4F19-80D9-66BA4E628364 at gmail.com>
> Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed
>
> Hi,
> The EFRATOM LPRO does not use a OCXO, just a straight quartz crystal
> oscillator.
> The control voltage swings around a volt as the base plate warms up.
> The time constant of the PLL that the XO is in must be quite short, a
> small fraction of a second
> so that the effect of drifting temperature has little effect on the
> output.
> I guess that all the crystal does is to filter what must be a quite
> noisy signal
> from the atomic resonance. When I inspected the circuit board I could
> not even find the crystal,
> it is not in a grand crystal can.
> cheers, Neville Michie
>
>
> On 23/10/2008, at 9:42 PM, WB6BNQ wrote:
>
>> Hi Bob Q,
>>
>> Yes Rubidium (Rb) and Cesium (Cs) standards use OCXO's.
>>
>> I suppose the way to look at it is the Rb or Cs chamber acts as an
>> invariant
>> atomic filter with extremely narrow bandpass (i.e., with an extremely
>> high Q).
>> The resonant frequencies of these atomic filters are up in the
>> microwave
>> regions
>> and thus do not lend themselves easily to direct comparison.  So, a
>> high
>> quality
>> standard frequency oscillator is locked in a loop controlled by the
>> atomic
>> filter.  The OCXO's output is the reference signal out of the atomic
>> standard.
>>
>> I hope this rather simplistic overview answers your question ?
>>
>> Bill....WB6BNQ
>>
>> Bob Q wrote:
>>
>>> Do rubidium standards use an OCXO?
>>> Bob Q.
>>>
>>> ----- Original Message -----
>>> From: "Rick Karlquist" <richard at karlquist.com>
>>> To: "Discussion of precise time and frequency measurement"
>>> <time-nuts at febo.com>
>>> Sent: Wednesday, October 22, 2008 2:23 PM
>>> Subject: Re: [time-nuts] Question on crystal jumps
>>>
>>>> I'm not quite sure what the question is here, but when
>>>> we made 10811 oscillators at HP, "jumps happened".  Some
>>>> crystals were better than others, but no crystal was immune
>>>> from jumps.  With good quality crystals, you might be able
>>>> to put an upper bound on the magnitude of jumps, like 10-9,
>>>> but not on the time between jumps.  I also noticed that there
>>>> didn't seem to be any correlation between jump activity
>>>> and stability between jumps.  You could have an oscillator
>>>> with really low aging, say a few parts in 1E11 per day that
>>>> looked really good for quite a while, but then the frequency
>>>> jumps.  After you've controlled everything you can about the
>>>> crystal process, the electronics, the oven and the environment,
>>>> you are still left with jumps.  If you want no jumps, go to
>>>> an atomic standard like rubidium.  There are mechanisms that
>>>> can cause jumps in rubidium standards as well, but good
>>>> rubidium standards don't jump.
>>>>
>>>> Rick Karlquist N6RK
>>>>
>>>>
>>>> iovane\@inwind\.it wrote:
>>>>> I would be very pleased to know when (date and time) anybody
>>>>> out there happened to record jumps in frequency of crystals.
>>>>> I have stable (e-07) tuning forks which happen to jump too,
>>>>> and I don't understand why, even having under control
>>>>> temperature and air pressure. Sometimes they return to their
>>>>> prior frequency with another jump, and this could happen even
>>>>> days later, sometimes they jump and then recover smoothly the
>>>>> prior frequency in a short time (such as one hour).
>>>>> I have no idea whether any correlations would exist between
>>>>> crystals and tuning forks jumps, regarding the causes that
>>>>> could trigger metastability, and hence I would have a look at
>>>>> crystal data in order to improve the base for future
>>>>> speculation.
>>>>>
>>>>> Thanks in advance.
>>>>> Antonio I8IOV
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> time-nuts mailing list -- time-nuts at febo.com
>>>>> To unsubscribe, go to
>>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>>>> and follow the instructions there.
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> time-nuts mailing list -- time-nuts at febo.com
>>>> To unsubscribe, go to
>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>>>> and follow the instructions there.
>>>
>>> _______________________________________________
>>> time-nuts mailing list -- time-nuts at febo.com
>>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/
>>> listinfo/time-nuts
>>> and follow the instructions there.
>>
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/
>> time-nuts
>> and follow the instructions there.
>
>
>
>
> ------------------------------
>
> _______________________________________________
> time-nuts mailing list
> time-nuts at febo.com
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>
> End of time-nuts Digest, Vol 51, Issue 73
> *****************************************
>


From wb6bnq at cox.net  Thu Oct 23 20:03:17 2008
From: wb6bnq at cox.net (WB6BNQ)
Date: Thu, 23 Oct 2008 13:03:17 -0700
Subject: [time-nuts] Question on crystal jumps
References: <K95RRZ$FAF15E0C201369F08F1E9E13C34A5EF0@libero.it><23695.192.25.240.225.1224710637.squirrel@webmail.sonic.net><002a01c934ad$cb5b13a0$1801a8c0@BOBCEL1R7>
	<49005522.FAE46EB7@cox.net> <000f01c93525$14745480$1801a8c0@BOBCEL1R7>
Message-ID: <4900D885.18169B79@cox.net>

Bob Q,

It will be interesting to hear Rick's explanation.

As Neville pointed out, the crystal oscillator does not have to be in an oven
environment.  However, compare a non-oven unit to a top of the line unit with an
OCXO and you will see a difference in the specs.  Part of that difference is the
quality of that OCXO.

Atomic standards are not without noise, particularly the Cs in the short term,
and Neville rightly points out that the crystal acts as a filter (or flywheel).
So, in one aspect, the needed level of resolution, and to some degree the
stability, would dictate the quality of the oscillator.

Of course, if you are a purist then nothing but the best is good enough.

Bill....WB6BNQ


Bob Q wrote:

> So why would they not show the same kind of jumps as plain OCXO's?  Rick K.
> mentioned atomic standards avoid jumps.
> Bob Q.
> ----- Original Message -----
> From: "WB6BNQ" <wb6bnq at cox.net>
> To: "Discussion of precise time and frequency measurement"
> <time-nuts at febo.com>
> Sent: Thursday, October 23, 2008 3:42 AM
> Subject: Re: [time-nuts] Question on crystal jumps
>
> > Hi Bob Q,
> >
> > Yes Rubidium (Rb) and Cesium (Cs) standards use OCXO's.
> >
> > I suppose the way to look at it is the Rb or Cs chamber acts as an
> > invariant
> > atomic filter with extremely narrow bandpass (i.e., with an extremely
> > high Q).
> > The resonant frequencies of these atomic filters are up in the microwave
> > regions
> > and thus do not lend themselves easily to direct comparison.  So, a high
> > quality
> > standard frequency oscillator is locked in a loop controlled by the
> > atomic
> > filter.  The OCXO's output is the reference signal out of the atomic
> > standard.
> >
> > I hope this rather simplistic overview answers your question ?
> >
> > Bill....WB6BNQ
> >
> > Bob Q wrote:
> >
> >> Do rubidium standards use an OCXO?
> >> Bob Q.
> >>
> >> ----- Original Message -----
> >> From: "Rick Karlquist" <richard at karlquist.com>
> >> To: "Discussion of precise time and frequency measurement"
> >> <time-nuts at febo.com>
> >> Sent: Wednesday, October 22, 2008 2:23 PM
> >> Subject: Re: [time-nuts] Question on crystal jumps
> >>
> >> > I'm not quite sure what the question is here, but when
> >> > we made 10811 oscillators at HP, "jumps happened".  Some
> >> > crystals were better than others, but no crystal was immune
> >> > from jumps.  With good quality crystals, you might be able
> >> > to put an upper bound on the magnitude of jumps, like 10-9,
> >> > but not on the time between jumps.  I also noticed that there
> >> > didn't seem to be any correlation between jump activity
> >> > and stability between jumps.  You could have an oscillator
> >> > with really low aging, say a few parts in 1E11 per day that
> >> > looked really good for quite a while, but then the frequency
> >> > jumps.  After you've controlled everything you can about the
> >> > crystal process, the electronics, the oven and the environment,
> >> > you are still left with jumps.  If you want no jumps, go to
> >> > an atomic standard like rubidium.  There are mechanisms that
> >> > can cause jumps in rubidium standards as well, but good
> >> > rubidium standards don't jump.
> >> >
> >> > Rick Karlquist N6RK
> >> >
> >> >
> >> > iovane\@inwind\.it wrote:
> >> >> I would be very pleased to know when (date and time) anybody
> >> >> out there happened to record jumps in frequency of crystals.
> >> >> I have stable (e-07) tuning forks which happen to jump too,
> >> >> and I don't understand why, even having under control
> >> >> temperature and air pressure. Sometimes they return to their
> >> >> prior frequency with another jump, and this could happen even
> >> >> days later, sometimes they jump and then recover smoothly the
> >> >> prior frequency in a short time (such as one hour).
> >> >> I have no idea whether any correlations would exist between
> >> >> crystals and tuning forks jumps, regarding the causes that
> >> >> could trigger metastability, and hence I would have a look at
> >> >> crystal data in order to improve the base for future
> >> >> speculation.
> >> >>
> >> >> Thanks in advance.
> >> >> Antonio I8IOV
> >> >>
> >> >>
> >> >>
> >> >> _______________________________________________
> >> >> time-nuts mailing list -- time-nuts at febo.com
> >> >> To unsubscribe, go to
> >> >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> >> >> and follow the instructions there.
> >> >>
> >> >>
> >> >
> >> >
> >> >
> >> > _______________________________________________
> >> > time-nuts mailing list -- time-nuts at febo.com
> >> > To unsubscribe, go to
> >> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> >> > and follow the instructions there.
> >>
> >> _______________________________________________
> >> time-nuts mailing list -- time-nuts at febo.com
> >> To unsubscribe, go to
> >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> >> and follow the instructions there.
> >
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at febo.com
> > To unsubscribe, go to
> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.



From tomduck at comcast.net  Thu Oct 23 20:19:00 2008
From: tomduck at comcast.net (Tom Duckworth)
Date: Thu, 23 Oct 2008 13:19:00 -0700
Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
In-Reply-To: <D7B1B5F4F3F27A4CB073BF422331203F0DD74642DD@Exchange1.lawo.de>
Message-ID: <mailman.3.1224793144.2536.time-nuts@febo.com>

Stefan,

I am retired from Pendulum Instruments and could answer your question but I
have instead refered your question to a current engineer with the company
and you should receive an answer from them shortly. They are the experts for
this question.

Tom
Tom Duckworth
510-886-1396
 

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Heinzmann, Stefan (ALC NetworX GmbH)
Sent: Thursday, October 23, 2008 10:12 AM
To: time-nuts at febo.com
Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81

Hi all,

I hope you can clear up some confusion that I have regarding ADEV
measurement. I was under the impression that you need a counter that is able
to timestamp each rising edge of the clock under test, or equivalently
measure period time continuously with no dead time. Now, while the CNT-90
can do this, the CNT-81 ( = PM6681 ) can't. Still, a message last December
to the list here
(http://www.mail-archive.com/time-nuts at febo.com/msg10963.html) seems to
indicate that using TimeView you can have ADEV plotted with the "lesser"
model, too. I have a PM6681 and TimeView, but I couldn't find out how to do
it. Maybe it can't be done.

So what's the deal on this? Can it be done, with or without TimeView, and if
yes, how? If this has been answered earlier, a link would be just fine.

Thanks and cheers
Stefan

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



From iovane at inwind.it  Thu Oct 23 22:15:24 2008
From: iovane at inwind.it (iovane at inwind.it)
Date: Fri, 24 Oct 2008 00:15:24 +0200
Subject: [time-nuts] Question on crystal jumps
Message-ID: <K97PTO$A6270C31E0BDB70B0C6A81ACEDB2249F@libero.it>

Hi all,

Thanks for your comments, info, ideas and references.

I've found the plots that Tim Shoppa pointed me to, and they
are a good response to my original question.

It has been interesting hearing about the jumps of pendulums
too, this was new to me.

Also I argue from the discussion that, while there has been in general a lot of speculation and study on the jumps of 
crystals, this didn't happen for pendulums. Quite obvious, as 
industry and military need crystals, not pendulums.

Regards,

Antonio I8IOV



> Antonio -
> 
> Folks have short (days) and long (multi-year) plots of the EFC in their
> Z3801A. The EFC is the correction factor to keep the 10811 inside
> phase-locked with GPS. At www.realhamradio.com you'll see an index
> of many many people's EFC plots.
>........ 
> Tim.




From sar10538 at gmail.com  Thu Oct 23 22:51:16 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Fri, 24 Oct 2008 11:51:16 +1300
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <K97PTO$A6270C31E0BDB70B0C6A81ACEDB2249F@libero.it>
References: <K97PTO$A6270C31E0BDB70B0C6A81ACEDB2249F@libero.it>
Message-ID: <1231b6a80810231551v58bcf8deye986e8c3d4f5f373@mail.gmail.com>

Hi,

I believe it was pointed out earlier that the output of a LPRO uses
some form of xtal oscillator as the output of the rubidium stage is
quite noisy. Considering the general consensus is that xtal
oscillators have these jumps, I wonder if the output of the rubidium
stage could be just passed directly through a multi-stage xtal lattice
filter to clean it up and use that directly and that may circumvent
the xtal jumps people are seeing.

73 - steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From SAIDJACK at aol.com  Thu Oct 23 22:56:19 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Thu, 23 Oct 2008 18:56:19 EDT
Subject: [time-nuts] Question on crystal jumps
Message-ID: <c14.4d9ab778.36325b13@aol.com>

Hi Steve,
 
the jumps are very slow in their frequency change, so the crystal filters  
would just follow the frequency drift. I have seen these jumps take from a few  
seconds to 20 minutes or so. Of course in a Rb they would be compensated by 
the  Rb pulling or pushing the crystal onto the proper frequency.
 
Also, the additional crystals in the filter will very likely jump too, so I  
would expect the overall performance to actually get worse.
 
bye,
Said
 
 
In a message dated 10/23/2008 15:53:05 Pacific Daylight Time,  
sar10538 at gmail.com writes:

oscillators have these jumps, I wonder if the output of the  rubidium
stage could be just passed directly through a multi-stage xtal  lattice
filter to clean it up and use that directly and that may  circumvent
the xtal jumps people are  seeing.



From bruce.griffiths at xtra.co.nz  Thu Oct 23 23:01:31 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Fri, 24 Oct 2008 12:01:31 +1300
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <1231b6a80810231551v58bcf8deye986e8c3d4f5f373@mail.gmail.com>
References: <K97PTO$A6270C31E0BDB70B0C6A81ACEDB2249F@libero.it>
	<1231b6a80810231551v58bcf8deye986e8c3d4f5f373@mail.gmail.com>
Message-ID: <4901024B.8000303@xtra.co.nz>

Steve Rooke wrote:
> Hi,
>
> I believe it was pointed out earlier that the output of a LPRO uses
> some form of xtal oscillator as the output of the rubidium stage is
> quite noisy. Considering the general consensus is that xtal
> oscillators have these jumps, I wonder if the output of the rubidium
> stage could be just passed directly through a multi-stage xtal lattice
> filter to clean it up and use that directly and that may circumvent
> the xtal jumps people are seeing.
>
> 73 - steve
>   
Steve

The rubidium standard is passive it doesnt oscillate, it merely acts as
a high Q filter whose resonance can be probed with an external source.
Thus you need to replace the crystal oscillator with another low noise
source to interrogate the rubidium resonance.

To be useful the bandpass filter would need a bandwidth of a few
milliHertz or less.
The crystals in the lattice filter will also experience similar jumps.

Bruce


From gwinn at raytheon.com  Thu Oct 23 23:57:44 2008
From: gwinn at raytheon.com (Joseph M Gwinn)
Date: Thu, 23 Oct 2008 19:57:44 -0400
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <4901024B.8000303@xtra.co.nz>
Message-ID: <OFBC2884BF.BBEB1792-ON852574EB.008380F0-852574EB.0083946B@mck.us.ray.com>

Would SAW oscillators be better than crystals?

Joe


time-nuts-bounces at febo.com wrote on 10/23/2008 07:01:31 PM:

> Steve Rooke wrote:
> > Hi,
> >
> > I believe it was pointed out earlier that the output of a LPRO uses
> > some form of xtal oscillator as the output of the rubidium stage is
> > quite noisy. Considering the general consensus is that xtal
> > oscillators have these jumps, I wonder if the output of the rubidium
> > stage could be just passed directly through a multi-stage xtal lattice
> > filter to clean it up and use that directly and that may circumvent
> > the xtal jumps people are seeing.
> >
> > 73 - steve
> > 
> Steve
> 
> The rubidium standard is passive it doesnt oscillate, it merely acts as
> a high Q filter whose resonance can be probed with an external source.
> Thus you need to replace the crystal oscillator with another low noise
> source to interrogate the rubidium resonance.
> 
> To be useful the bandpass filter would need a bandwidth of a few
> milliHertz or less.
> The crystals in the lattice filter will also experience similar jumps.
> 
> Bruce
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-
> bin/mailman/listinfo/time-nuts
> and follow the instructions there.



From bruce.griffiths at xtra.co.nz  Fri Oct 24 00:15:01 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Fri, 24 Oct 2008 13:15:01 +1300
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <OFBC2884BF.BBEB1792-ON852574EB.008380F0-852574EB.0083946B@mck.us.ray.com>
References: <OFBC2884BF.BBEB1792-ON852574EB.008380F0-852574EB.0083946B@mck.us.ray.com>
Message-ID: <49011385.2070804@xtra.co.nz>

Joseph M Gwinn wrote:
> Would SAW oscillators be better than crystals?
>
> Joe
>
>
>   
They still relay on using a piezoelectric crystal as does a BAW oscillator.
There's no reson to believe that they would be immune to frequency jumps.

It may be better (aside from costs) to just use a very large sapphire
whispering gallery resonator.

Bruce


From jim77742 at gmail.com  Fri Oct 24 00:15:39 2008
From: jim77742 at gmail.com (Jim Palfreyman)
Date: Fri, 24 Oct 2008 11:15:39 +1100
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <1231b6a80810231551v58bcf8deye986e8c3d4f5f373@mail.gmail.com>
References: <K97PTO$A6270C31E0BDB70B0C6A81ACEDB2249F@libero.it>
	<1231b6a80810231551v58bcf8deye986e8c3d4f5f373@mail.gmail.com>
Message-ID: <f616e0f80810231715m62b7e2a6g6004b0dac796b069@mail.gmail.com>

This discussion has come at an interesting time.

I've hooked up an LPRO-101 from ebay to an AVR micro-controller - basically
using it to clock the processor directly.

I've written code so the AVR is a clock and I've been comparing my clock's 1
PPS to the GPS.

Over a few minutes it hops back and forward a few hundred nsec. All quite
acceptable given the clock speed.

When I come back after a few hours it will suddenly be 10-20 usec slow. I
did see it jump over a few seconds from 200nsec to 17 usec.

At first I put this down to interference because it coincide with me
switching off a light. So I put the whole lot into a metal box, shorter
wires and tried again.

It still has jumps but this time it is *gaining*.

Until this post started I'd assumed it was maybe my code and was about to
dive in and check it.

Could these crystal "jumps" account for my issues?

Regards,

Jim


2008/10/24 Steve Rooke <sar10538 at gmail.com>

> Hi,
>
> I believe it was pointed out earlier that the output of a LPRO uses
> some form of xtal oscillator as the output of the rubidium stage is
> quite noisy. Considering the general consensus is that xtal
> oscillators have these jumps, I wonder if the output of the rubidium
> stage could be just passed directly through a multi-stage xtal lattice
> filter to clean it up and use that directly and that may circumvent
> the xtal jumps people are seeing.
>
> 73 - steve
> --
> Steve Rooke - ZL3TUV & G8KVD
> Omnium finis imminet
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

From SAIDJACK at aol.com  Fri Oct 24 00:28:23 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Thu, 23 Oct 2008 20:28:23 EDT
Subject: [time-nuts] Question on crystal jumps
Message-ID: <be7.3c91ba02.363270a7@aol.com>

Hi Jim,
 
not sure about that, in a Rubidium (and GPSDO) these jumps are sensed, and  
corrected for. I would not expect the errors to last so long.
 
Then again, if your OCXO jumps A LOT, maybe even the Lpro PLL loop cannot  
fully compensate for the errors.
 
bye,
Said
 
 
In a message dated 10/23/2008 17:16:51 Pacific Daylight Time,  
jim77742 at gmail.com writes:

It still  has jumps but this time it is *gaining*.

Until this post started I'd  assumed it was maybe my code and was about to
dive in and check  it.

Could these crystal "jumps" account for my  issues?

Regards,

Jim



From gwinn at raytheon.com  Fri Oct 24 00:39:40 2008
From: gwinn at raytheon.com (Joseph M Gwinn)
Date: Thu, 23 Oct 2008 20:39:40 -0400
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <49011385.2070804@xtra.co.nz>
Message-ID: <OF398F0B63.E4A3540A-ON852574EC.00031BF1-852574EC.00039519@mck.us.ray.com>

time-nuts-bounces at febo.com wrote on 10/23/2008 08:15:01 PM:

> Joseph M Gwinn wrote:
> > Would SAW oscillators be better than crystals?
> >
> > Joe
> >
> >
> > 
> They still rely on using a piezoelectric crystal as does a BAW
> oscillator.
> There's no reason to believe that they would be immune to frequency 
jumps.

Reminds me of popcorn noise in semiconductors.  It turned out to be caused 
by impurities in the materials, and has largely been solved by process 
improvements.

SAWs are made by a very different process than bulk crystals, so one may 
get lucky. 


> It may be better (aside from costs) to just use a very large sapphire
> whispering gallery resonator.

A higher frequency could be an advantage in the "crystal" oscillator of a 
Rb oscillator.  One can then divide the higher frequency down to 10 MHz, 
perhaps improving phase noise in the process.

I suppose a SAW could be made of sapphire, if it's piezeoelectric enough.

Joe


> Bruce
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-
> bin/mailman/listinfo/time-nuts
> and follow the instructions there.



From bruce.griffiths at xtra.co.nz  Fri Oct 24 00:51:17 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Fri, 24 Oct 2008 13:51:17 +1300
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <OF398F0B63.E4A3540A-ON852574EC.00031BF1-852574EC.00039519@mck.us.ray.com>
References: <OF398F0B63.E4A3540A-ON852574EC.00031BF1-852574EC.00039519@mck.us.ray.com>
Message-ID: <49011C05.9090005@xtra.co.nz>

Joseph M Gwinn wrote:
>> It may be better (aside from costs) to just use a very large sapphire
>> whispering gallery resonator.
>>     
>
> A higher frequency could be an advantage in the "crystal" oscillator of a 
> Rb oscillator.  One can then divide the higher frequency down to 10 MHz, 
> perhaps improving phase noise in the process.
>
> I suppose a SAW could be made of sapphire, if it's piezeoelectric enough.
>
> Joe
>
>
>   
>> Bruce
>>
>>     
Joe

Saphire isnt piezoelectric.
The idea being that there may be some advantage in not using an acoustic
wave resonator but a microwave resonator with extremely high Q (at least
at Liquid helium temperatures).
However the cost will usually be prohibitive.
Cryogenic sapphire whispering gallery resonators are known to have
greater short term stabilities that even the best crystal oscillator.

Bruce


From brooke at pacific.net  Fri Oct 24 00:58:43 2008
From: brooke at pacific.net (Brooke Clarke)
Date: Thu, 23 Oct 2008 17:58:43 -0700
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <f616e0f80810231715m62b7e2a6g6004b0dac796b069@mail.gmail.com>
References: <K97PTO$A6270C31E0BDB70B0C6A81ACEDB2249F@libero.it>	<1231b6a80810231551v58bcf8deye986e8c3d4f5f373@mail.gmail.com>
	<f616e0f80810231715m62b7e2a6g6004b0dac796b069@mail.gmail.com>
Message-ID: <49011DC3.6050906@pacific.net>

Hi Jim:

I've made similar clocks using PIC micro controllers where the input is the 10 
MHz from the frequency standard.
http://www.prc68.com/I/PRC68COM.shtml#07092006

There's a subtle problem that has to do with if an interrupt occurs during a 3 
cycle long instruction or a 2 cycle long instruction.  This can cause erratic 
behavior if not properly accounted for.

The 1 PPS from your clock should be spot on all the time, not off by a few 
hundred nano seconds.

Have Fun,

Brooke Clarke
http://www.prc68.com/P/Prod.html  Products I make and sell
http://www.prc68.com/Alpha.shtml  All my web pages listed based on html name
http://www.PRC68.com
http://www.precisionclock.com
http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Web Cam

Jim Palfreyman wrote:
> This discussion has come at an interesting time.
> 
> I've hooked up an LPRO-101 from ebay to an AVR micro-controller - basically
> using it to clock the processor directly.
> 
> I've written code so the AVR is a clock and I've been comparing my clock's 1
> PPS to the GPS.
> 
> Over a few minutes it hops back and forward a few hundred nsec. All quite
> acceptable given the clock speed.
> 
> When I come back after a few hours it will suddenly be 10-20 usec slow. I
> did see it jump over a few seconds from 200nsec to 17 usec.
> 
> At first I put this down to interference because it coincide with me
> switching off a light. So I put the whole lot into a metal box, shorter
> wires and tried again.
> 
> It still has jumps but this time it is *gaining*.
> 
> Until this post started I'd assumed it was maybe my code and was about to
> dive in and check it.
> 
> Could these crystal "jumps" account for my issues?
> 
> Regards,
> 
> Jim


From jim77742 at gmail.com  Fri Oct 24 01:12:24 2008
From: jim77742 at gmail.com (Jim Palfreyman)
Date: Fri, 24 Oct 2008 12:12:24 +1100
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <49011DC3.6050906@pacific.net>
References: <K97PTO$A6270C31E0BDB70B0C6A81ACEDB2249F@libero.it>
	<1231b6a80810231551v58bcf8deye986e8c3d4f5f373@mail.gmail.com>
	<f616e0f80810231715m62b7e2a6g6004b0dac796b069@mail.gmail.com>
	<49011DC3.6050906@pacific.net>
Message-ID: <f616e0f80810231812t38eee2a1xa3638722135250b@mail.gmail.com>

Thanks Brooke,

Just letting you know I've written the code without interrupts.

Basically I set the internal 16 bit timer to count up and watch it in an
infinite loop. After it gets to a certain number then I reset the timer to
zero and count a "tick". I count these ticks and get my time and 1 PPS from
this.

I recognise there are some possible flaws in my method. I'd expect the flaws
to represent themselves as a slow drift in accuracy of the 1 PPS and/or some
sawtooth of the order of 100ns (1/10 MHz) about the true 1 PPS.

What I wasn't expecting was these jumps of the order of tens of
microseconds.

I suppose a solution is to take the 10MHz from my Thunderbolt and use that
to drive the AVR and see if the problem remains and the fault is in the
LPRO.

Jim


2008/10/24 Brooke Clarke <brooke at pacific.net>

> Hi Jim:
>
> I've made similar clocks using PIC micro controllers where the input is the
> 10
> MHz from the frequency standard.
> http://www.prc68.com/I/PRC68COM.shtml#07092006
>
> There's a subtle problem that has to do with if an interrupt occurs during
> a 3
> cycle long instruction or a 2 cycle long instruction.  This can cause
> erratic
> behavior if not properly accounted for.
>
> The 1 PPS from your clock should be spot on all the time, not off by a few
> hundred nano seconds.
>
> Have Fun,
>
> Brooke Clarke
> http://www.prc68.com/P/Prod.html  Products I make and sell
> http://www.prc68.com/Alpha.shtml  All my web pages listed based on html
> name
> http://www.PRC68.com
> http://www.precisionclock.com
> http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Web Cam
>
> Jim Palfreyman wrote:
> > This discussion has come at an interesting time.
> >
> > I've hooked up an LPRO-101 from ebay to an AVR micro-controller -
> basically
> > using it to clock the processor directly.
> >
> > I've written code so the AVR is a clock and I've been comparing my
> clock's 1
> > PPS to the GPS.
> >
> > Over a few minutes it hops back and forward a few hundred nsec. All quite
> > acceptable given the clock speed.
> >
> > When I come back after a few hours it will suddenly be 10-20 usec slow. I
> > did see it jump over a few seconds from 200nsec to 17 usec.
> >
> > At first I put this down to interference because it coincide with me
> > switching off a light. So I put the whole lot into a metal box, shorter
> > wires and tried again.
> >
> > It still has jumps but this time it is *gaining*.
> >
> > Until this post started I'd assumed it was maybe my code and was about to
> > dive in and check it.
> >
> > Could these crystal "jumps" account for my issues?
> >
> > Regards,
> >
> > Jim
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

From sar10538 at gmail.com  Fri Oct 24 02:21:36 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Fri, 24 Oct 2008 15:21:36 +1300
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <c14.4d9ab778.36325b13@aol.com>
References: <c14.4d9ab778.36325b13@aol.com>
Message-ID: <1231b6a80810231921q38c2a8cfk5b8739734935e5bc@mail.gmail.com>

2008/10/24  <SAIDJACK at aol.com>:
> the jumps are very slow in their frequency change, so the crystal filters
> would just follow the frequency drift. I have seen these jumps take from a few
> seconds to 20 minutes or so. Of course in a Rb they would be compensated by
> the  Rb pulling or pushing the crystal onto the proper frequency.

But I'm not suggesting that the rubidium stage is used to discipline a
ocxo and then fed onto a xtal lattice filter, I meant that the
rubidium stage would go directly into the xtal lattice filter. This
way there is no xtal oscillator to jump off frequency.

> Also, the additional crystals in the filter will very likely jump too, so I
> would expect the overall performance to actually get worse.

If the jump is due to tiny physical effects on a crystal edge, as
previously described, I would doubt that every xtal would be exactly
the same wrt this and I very much doubt that all the xtals in a
lattice filter would jump at the same time and in the same way. This
type of filter works on the basis that each element suppresses signal
outside its centre frequency. If one xtal changes it's centre
frequency, all that changes is that the signal level at that stage
output drops (as in an off-tuned tuned circuit in a multi-stage filter
would do). Also the probabilities that every xtal would jump at the
same time would surely be very high and I'm not sure that using a xtal
in a filter circuit would be subceptable to this jumping in the same
way as using it in an oscillator circuit.

Now if the jumps were caused by something like a cosmic ray, I would
expect that the xtal would just wobble off frequency rapidly and very
quickly go back to its resonant frequency. Using a multi-stage xtal
filter should circumvent this as the particle would have to physically
strike all the xtals in the filter on it's path. Physical arrangement
of the xtals in the filter would easily guard against that.

If the jumps are caused by gravitational effects, it should be
similarly possible to design the filter the be less prone to these
affects by the orientation of the xtals.

73 - Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From jim77742 at gmail.com  Fri Oct 24 02:32:34 2008
From: jim77742 at gmail.com (Jim Palfreyman)
Date: Fri, 24 Oct 2008 13:32:34 +1100
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <1231b6a80810231921q38c2a8cfk5b8739734935e5bc@mail.gmail.com>
References: <c14.4d9ab778.36325b13@aol.com>
	<1231b6a80810231921q38c2a8cfk5b8739734935e5bc@mail.gmail.com>
Message-ID: <f616e0f80810231932n8dc6515sad2c352bfb354960@mail.gmail.com>

> If the jumps are caused by gravitational effects, it should be
> similarly possible to design the filter the be less prone to these
> affects by the orientation of the xtals.
>
>
If the jumps were caused by gravitational effects there's a whole bunch of
physicists trying to detect gravitational waves in mind-numbing ways (read
about LISA at
http://en.wikipedia.org/wiki/Laser_Interferometer_Space_Antenna ) who would
just *love* to know!

(and you'd probably get a Nobel Prize thrown in)

Jim

From bruce.griffiths at xtra.co.nz  Fri Oct 24 02:36:00 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Fri, 24 Oct 2008 15:36:00 +1300
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <1231b6a80810231921q38c2a8cfk5b8739734935e5bc@mail.gmail.com>
References: <c14.4d9ab778.36325b13@aol.com>
	<1231b6a80810231921q38c2a8cfk5b8739734935e5bc@mail.gmail.com>
Message-ID: <49013490.20507@xtra.co.nz>

Steve Rooke wrote:
> 2008/10/24  <SAIDJACK at aol.com>:
>   
>> the jumps are very slow in their frequency change, so the crystal filters
>> would just follow the frequency drift. I have seen these jumps take from a few
>> seconds to 20 minutes or so. Of course in a Rb they would be compensated by
>> the  Rb pulling or pushing the crystal onto the proper frequency.
>>     
>
> But I'm not suggesting that the rubidium stage is used to discipline a
> ocxo and then fed onto a xtal lattice filter, I meant that the
> rubidium stage would go directly into the xtal lattice filter. This
> way there is no xtal oscillator to jump off frequency.
>
>   
Steve

You've missed a vital point:
There is no RF output from the rubidium cell itself at all.
It doesn't oscillate as does an active hydrogen maser.


Bruc




From brooke at pacific.net  Fri Oct 24 02:39:32 2008
From: brooke at pacific.net (Brooke Clarke)
Date: Thu, 23 Oct 2008 19:39:32 -0700
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <1231b6a80810231921q38c2a8cfk5b8739734935e5bc@mail.gmail.com>
References: <c14.4d9ab778.36325b13@aol.com>
	<1231b6a80810231921q38c2a8cfk5b8739734935e5bc@mail.gmail.com>
Message-ID: <49013564.3060107@pacific.net>

Hi Steve:

There is no Rubidium oscillator.  See the block diagram at:
http://www.prc68.com/I/PRS10.shtml#BlkDia
The amount of light passing through the Rb cell is used to steer a quartz 
oscillator.  In the case of the PRS10 it's an ovenized oscillator that's an 
improved and smaller version of their SC10.

Have Fun,

Brooke Clarke
http://www.prc68.com/P/Prod.html  Products I make and sell
http://www.prc68.com/Alpha.shtml  All my web pages listed based on html name
http://www.PRC68.com
http://www.precisionclock.com
http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Web Cam

Steve Rooke wrote:
> 2008/10/24  <SAIDJACK at aol.com>:
>> the jumps are very slow in their frequency change, so the crystal filters
>> would just follow the frequency drift. I have seen these jumps take from a few
>> seconds to 20 minutes or so. Of course in a Rb they would be compensated by
>> the  Rb pulling or pushing the crystal onto the proper frequency.
> 
> But I'm not suggesting that the rubidium stage is used to discipline a
> ocxo and then fed onto a xtal lattice filter, I meant that the
> rubidium stage would go directly into the xtal lattice filter. This
> way there is no xtal oscillator to jump off frequency.
> 
>> Also, the additional crystals in the filter will very likely jump too, so I
>> would expect the overall performance to actually get worse.
> 
> If the jump is due to tiny physical effects on a crystal edge, as
> previously described, I would doubt that every xtal would be exactly
> the same wrt this and I very much doubt that all the xtals in a
> lattice filter would jump at the same time and in the same way. This
> type of filter works on the basis that each element suppresses signal
> outside its centre frequency. If one xtal changes it's centre
> frequency, all that changes is that the signal level at that stage
> output drops (as in an off-tuned tuned circuit in a multi-stage filter
> would do). Also the probabilities that every xtal would jump at the
> same time would surely be very high and I'm not sure that using a xtal
> in a filter circuit would be subceptable to this jumping in the same
> way as using it in an oscillator circuit.
> 
> Now if the jumps were caused by something like a cosmic ray, I would
> expect that the xtal would just wobble off frequency rapidly and very
> quickly go back to its resonant frequency. Using a multi-stage xtal
> filter should circumvent this as the particle would have to physically
> strike all the xtals in the filter on it's path. Physical arrangement
> of the xtals in the filter would easily guard against that.
> 
> If the jumps are caused by gravitational effects, it should be
> similarly possible to design the filter the be less prone to these
> affects by the orientation of the xtals.
> 
> 73 - Steve


From sar10538 at gmail.com  Fri Oct 24 02:52:42 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Fri, 24 Oct 2008 15:52:42 +1300
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <4901024B.8000303@xtra.co.nz>
References: <K97PTO$A6270C31E0BDB70B0C6A81ACEDB2249F@libero.it>
	<1231b6a80810231551v58bcf8deye986e8c3d4f5f373@mail.gmail.com>
	<4901024B.8000303@xtra.co.nz>
Message-ID: <1231b6a80810231952m2f01781frc1d4d66d44bd3fd6@mail.gmail.com>

2008/10/24 Bruce Griffiths <bruce.griffiths at xtra.co.nz>:
> The rubidium standard is passive it doesnt oscillate, it merely acts as
> a high Q filter whose resonance can be probed with an external source.
> Thus you need to replace the crystal oscillator with another low noise
> source to interrogate the rubidium resonance.

So, do I take it you are suggesting that the xtal oscillator is used
to excite the rubidium standard? I can't see how that works, can you
please comment further.

> To be useful the bandpass filter would need a bandwidth of a few
> milliHertz or less.

Well, if the xtals we use are capable of resonating sufficiently well
to provide us with a freq standard that is acceptable for our uses,
IE. within a few miliHertz, I can only see that using multiple xtals
can only improve on the stability of a singe xtal in an oscillator
circuit. Remember that the output of these GPSDOs, and as I understand
it rubidium standards, are really the output of the xtal oscillator.
The centre frequency of that xtal oscillator is relatively slowly
varied to be correct by it's difference to the GPS signal, or rubidum
stage, via some form of comparator driving a low pass filter and onto
the EFC. Hence it is the xtal oscillator which is the signal source we
see.

> The crystals in the lattice filter will also experience similar jumps.

But it is highly probable that they will not all jump at the same time
for reasons I have given in a previous posting. It's similar to what
other people have described about using three or more xtal oscillators
and having a vote on what the frequency should be. Trying to control
multiple oscillators, and implement the voting arrangement, would be
quite complex and has a high probability of being prone to other
effects. A lattice filter is very simple in comparison, you have the
same voting scheme of multiple xtals (and you can have many more than
three) but none of the complexity of the oscillator arrangement. You
just have to make sure that it is driven with the reference standard
and all the stages could be manually tuned for peak after a burn in.
As the xtals change over time the level may drop but the frequency
would remain as stable as the input reference. Of course, if you used
just a very simple lattice, it's possible for all the xtals to drift
in one direction which would make the filter less able to suppress
noise sidebands but it would need to have some math done to
investigate the implications of this. Also a series parallel design
would probably circumvent this.

Sorry, just thinking out loud.

73 - Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From bruce.griffiths at xtra.co.nz  Fri Oct 24 03:14:26 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Fri, 24 Oct 2008 16:14:26 +1300
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <1231b6a80810231952m2f01781frc1d4d66d44bd3fd6@mail.gmail.com>
References: <K97PTO$A6270C31E0BDB70B0C6A81ACEDB2249F@libero.it>	<1231b6a80810231551v58bcf8deye986e8c3d4f5f373@mail.gmail.com>	<4901024B.8000303@xtra.co.nz>
	<1231b6a80810231952m2f01781frc1d4d66d44bd3fd6@mail.gmail.com>
Message-ID: <49013D92.4080104@xtra.co.nz>

Steve Rooke wrote:
> 2008/10/24 Bruce Griffiths <bruce.griffiths at xtra.co.nz>:
>   
>> The rubidium standard is passive it doesnt oscillate, it merely acts as
>> a high Q filter whose resonance can be probed with an external source.
>> Thus you need to replace the crystal oscillator with another low noise
>> source to interrogate the rubidium resonance.
>>     
>
> So, do I take it you are suggesting that the xtal oscillator is used
> to excite the rubidium standard? I can't see how that works, can you
> please comment further.
>
>   
The crystal oscillator is used to drive a frequency synthesizer chain
that has an output at 6.8.....GHz.
This output is then used to interrogate the Rubidium resonance at 6.8GHz
using a derivative of the Pound technique.
The resultant modulation of the optical transmission of the Rubidium
cell is used to lock the 6.8...GHz signal to the Rubidium transition.

Caesium beam standards are also passive and a synthesized 9.192....GHz
signal is locked to the desired Caesium 133 transition.
>> To be useful the bandpass filter would need a bandwidth of a few
>> milliHertz or less.
>>     
>
> Well, if the xtals we use are capable of resonating sufficiently well
> to provide us with a freq standard that is acceptable for our uses,
> IE. within a few miliHertz, I can only see that using multiple xtals
> can only improve on the stability of a singe xtal in an oscillator
> circuit. Remember that the output of these GPSDOs, and as I understand
> it rubidium standards, are really the output of the xtal oscillator.
> The centre frequency of that xtal oscillator is relatively slowly
> varied to be correct by it's difference to the GPS signal, or rubidum
> stage, via some form of comparator driving a low pass filter and onto
> the EFC. Hence it is the xtal oscillator which is the signal source we
> see.
>
>   
In practice you cant achieve a crystal Q greater than a few million at
10MHz, so achieving a filter bandpass of a few millihertz is a little
difficult to do.
Using several crystals in an oscillator is a well known technique for
increasing the group delay and improving the oscillator short term
stability.
>> The crystals in the lattice filter will also experience similar jumps.
>>     
>
> But it is highly probable that they will not all jump at the same time
> for reasons I have given in a previous posting. It's similar to what
> other people have described about using three or more xtal oscillators
> and having a vote on what the frequency should be. Trying to control
> multiple oscillators, and implement the voting arrangement, would be
> quite complex and has a high probability of being prone to other
> effects. A lattice filter is very simple in comparison, you have the
> same voting scheme of multiple xtals (and you can have many more than
> three) but none of the complexity of the oscillator arrangement. You
> just have to make sure that it is driven with the reference standard
> and all the stages could be manually tuned for peak after a burn in.
> As the xtals change over time the level may drop but the frequency
> would remain as stable as the input reference. Of course, if you used
> just a very simple lattice, it's possible for all the xtals to drift
> in one direction which would make the filter less able to suppress
> noise sidebands but it would need to have some math done to
> investigate the implications of this. Also a series parallel design
> would probably circumvent this.
>
> Sorry, just thinking out loud.
>
> 73 - Steve
>   
A jump in the parameters of any of the crystals will still perturb the
phase shift of the crystal filter wehther it is used as a passive filter
or the frequency determining element in an oscillator.

Bruce


From sar10538 at gmail.com  Fri Oct 24 03:28:41 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Fri, 24 Oct 2008 16:28:41 +1300
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <49013490.20507@xtra.co.nz>
References: <c14.4d9ab778.36325b13@aol.com>
	<1231b6a80810231921q38c2a8cfk5b8739734935e5bc@mail.gmail.com>
	<49013490.20507@xtra.co.nz>
Message-ID: <1231b6a80810232028r42b1dfa0h48cccd2503b4a4bf@mail.gmail.com>

Bruce,

2008/10/24 Bruce Griffiths <bruce.griffiths at xtra.co.nz>:
> You've missed a vital point:
> There is no RF output from the rubidium cell itself at all.
> It doesn't oscillate as does an active hydrogen maser.

Thanks for putting me right on this, I obviously need to study this
more. So as I see it, a CPU measures the output of the rubidium lamp
and tunes a signal source which is used to excite the lamp to give the
highest output. The output of the signal source is used to discipline
a 10MHz ocxo and the output of this becomes our reference standard.
Well, we are at the mercy of the xtal oscillator, if it jumps, so does
the output, straight away, and it does not matter how good our high Q
rb standard is as there will be a jump which should be corrected by
the feedback circuit, IE. the output of the ru lamp photo detector
will go down and the cpu will have to correct it causing the oxco to
be corrected again. How long this takes is down to the time constand
of the feedback mechanism.

OK, even given this setup, would it not be possible to remove the ocxo
from the loop and just use the cpu to control a non-xtal'd signal
source rb exciter. The output of this signal source could then be
divided down to 10MHz and filtered. I appreciate that using a rb
exciter that is not disciplined would not be as stable but with good
design this can be mitigated and, once the signal generator is on
frequency it should be possible to keep it that way with the optical
feedback to the cpu without a lot of noise from the cpu hunting for
the photo detector peak. After all, in the ocxo design, this is also
being varied by the cpu and can be kept stable so why not the rb
exciter oscillator as well.

73 - Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From bruce.griffiths at xtra.co.nz  Fri Oct 24 03:44:56 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Fri, 24 Oct 2008 16:44:56 +1300
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <1231b6a80810232028r42b1dfa0h48cccd2503b4a4bf@mail.gmail.com>
References: <c14.4d9ab778.36325b13@aol.com>	<1231b6a80810231921q38c2a8cfk5b8739734935e5bc@mail.gmail.com>	<49013490.20507@xtra.co.nz>
	<1231b6a80810232028r42b1dfa0h48cccd2503b4a4bf@mail.gmail.com>
Message-ID: <490144B8.1050205@xtra.co.nz>

Steve Rooke wrote:
> Bruce,
>
> 2008/10/24 Bruce Griffiths <bruce.griffiths at xtra.co.nz>:
>   
>> You've missed a vital point:
>> There is no RF output from the rubidium cell itself at all.
>> It doesn't oscillate as does an active hydrogen maser.
>>     
>
> Thanks for putting me right on this, I obviously need to study this
> more. So as I see it, a CPU measures the output of the rubidium lamp
> and tunes a signal source which is used to excite the lamp to give the
> highest output. The output of the signal source is used to discipline
> a 10MHz ocxo and the output of this becomes our reference standard.
> Well, we are at the mercy of the xtal oscillator, if it jumps, so does
> the output, straight away, and it does not matter how good our high Q
> rb standard is as there will be a jump which should be corrected by
> the feedback circuit, IE. the output of the ru lamp photo detector
> will go down and the cpu will have to correct it causing the oxco to
> be corrected again. How long this takes is down to the time constand
> of the feedback mechanism.
>
> OK, even given this setup, would it not be possible to remove the ocxo
> from the loop and just use the cpu to control a non-xtal'd signal
> source rb exciter. The output of this signal source could then be
> divided down to 10MHz and filtered. I appreciate that using a rb
> exciter that is not disciplined would not be as stable but with good
> design this can be mitigated and, once the signal generator is on
> frequency it should be possible to keep it that way with the optical
> feedback to the cpu without a lot of noise from the cpu hunting for
> the photo detector peak. After all, in the ocxo design, this is also
> being varied by the cpu and can be kept stable so why not the rb
> exciter oscillator as well.
>
> 73 - Steve
>   
Steve

The change in light transmission is very small ~ 0.1% so an AC phase
sensitive detection technique is used.
The probe signal frequency is modulated at a relatively low frequency
(usually < 200Hz).
When the interrogating frequency is tuned to the resonance the
transmitted light flux has a modulation component at twice the
modulation frequency and none at the modulation frequency.
When the frequency is slightly off the transmitted light flux has a
frequency component at the modulation frequency with a phase that is
indicative of whether the frequency is high or low.
For small frequency errors the amplitude of the light flux component at
the modulation frequency ids proportional to the frequency error.
Thus a synchronous detector can be detect the transmitted light flux
component at the modulation frequency and steer the frequency to the
rubidium hyperfine transition frequency.

The signal to noise ratio isnt that high so a low noise oscillator with
good short term stability is required.
Typically a crystal oscillator is used because very few other
oscillators have adequate short term stability.

Superconducting resonator and cryogenic sapphire stabilised oscillators
are exceptions.
A conventional LC oscillator, is too unstable to be useful.

Bruce


From SAIDJACK at aol.com  Fri Oct 24 04:25:58 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Fri, 24 Oct 2008 00:25:58 EDT
Subject: [time-nuts] Question on crystal jumps
Message-ID: <c46.43abc033.3632a856@aol.com>

Hi Steve,
 
the jumps don't anneal themselves, they are permanent changes in  frequency.
 
The crystal is off-frequency after a jump. This has to be compensated by  
driving the crystal with a different voltage after the jump.

See the following plot, blue is phase offset to UTC, brown is EFC  voltage.

You can see that the voltage is different after the jump, meaning the  
crystal has physically changed in some way.
 
bye,
Said
 
 
In a message dated 10/23/2008 19:23:54 Pacific Daylight Time,  
sar10538 at gmail.com writes:

Now if  the jumps were caused by something like a cosmic ray, I would
expect that  the xtal would just wobble off frequency rapidly and very
quickly go back  to its resonant frequency. Using a multi-stage xtal
filter should  circumvent this as the particle would have to physically
strike all the  xtals in the filter on it's path. Physical arrangement
of the xtals in the  filter would easily guard against  that.


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From jim77742 at gmail.com  Fri Oct 24 04:26:28 2008
From: jim77742 at gmail.com (Jim Palfreyman)
Date: Fri, 24 Oct 2008 15:26:28 +1100
Subject: [time-nuts] OT: Open Hardware Repository
In-Reply-To: <83e48fa10810220119n3d3d6df6r348efc68ddca5d17@mail.gmail.com>
References: <83e48fa10810220119n3d3d6df6r348efc68ddca5d17@mail.gmail.com>
Message-ID: <f616e0f80810232126p66f686b5vc11998151a576958@mail.gmail.com>

I like it. When is it ready?

Jim


2008/10/22 Javier Serrano <javier.serrano.pareja at gmail.com>

> Dear nuts,
>
> Sorry for this posting, only indirectly related to timing. For a long time
> I've been toying with the idea of a web-based Open Hardware Repository, and
> now it looks like we could allocate some resources to building it. Here are
> some preliminary and unofficial specs:
>
> http://ab-dep-co-ht.web.cern.ch/ab-dep-co-ht/documents/2008/Hardware/OHRFuncSpec.pdf
> .
> I have not found anywhere a kind of repository which would match these
> requirements completely. It's intended to be for PCB design, in a much more
> humble scale, what source forge is for software or opencores.org is for
> HDL.
> Since many of the designs we'd put there are timing-related, I thought I'd
> ask you for feedback:
> - Do you think this is a good idea?
> - Does this exist already somewhere?
> - Any comments on the specs?
> Feel free to answer directly to me if you think this is really off topic. I
> would not like to spoil the fine SNR of this list. If I see there's lots of
> interest I will post a summary.
>
> Thanks,
>
> Javier
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

From namichie at gmail.com  Fri Oct 24 05:25:49 2008
From: namichie at gmail.com (Neville Michie)
Date: Fri, 24 Oct 2008 16:25:49 +1100
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: <c46.43abc033.3632a856@aol.com>
References: <c46.43abc033.3632a856@aol.com>
Message-ID: <FE1247A1-F9CC-419D-9928-E5A6E4DF25F2@gmail.com>

Hi,
My insight into frequency jumps in xtals is that they may be due to a  
number of
of mechanisms, but are within the range of our experience.
When grinding solids the surface is rough so we use decreasing sizes  
of grinding medium
to polish through scratches, but a deep chip may leave a partly  
attached particle at the surface.
Small microcracks may extend themselves short distances.
Cosmic ray events may implant and atom into the lattice, straining it.
Loose particles may attach to the surface (but then we may see a  
reversal as they let go later)
Gold plating may be developing cracks, or loosing particles.
Remember at the very small particle size, the force of attraction to  
mass ratio is much higher than
for large particles.
Does chemical etching reduce the frequency of micro-jumps?
Can quartz crystals be thermally annealed?
What is interesting is the ageing mechanisms. Does gross thermal  
cycling reduce ageing?
just some thoughts,
Neville mIchie




On 24/10/2008, at 3:25 PM, SAIDJACK at aol.com wrote:

> Hi Steve,
>
> the jumps don't anneal themselves, they are permanent changes in   
> frequency.
>
> The crystal is off-frequency after a jump. This has to be  
> compensated by
> driving the crystal with a different voltage after the jump.
>
> See the following plot, blue is phase offset to UTC, brown is EFC   
> voltage.
>
> You can see that the voltage is different after the jump, meaning the
> crystal has physically changed in some way.
>
> bye,
> Said
>
>
> In a message dated 10/23/2008 19:23:54 Pacific Daylight Time,
> sar10538 at gmail.com writes:
>
> Now if  the jumps were caused by something like a cosmic ray, I would
> expect that  the xtal would just wobble off frequency rapidly and very
> quickly go back  to its resonant frequency. Using a multi-stage xtal
> filter should  circumvent this as the particle would have to  
> physically
> strike all the  xtals in the filter on it's path. Physical arrangement
> of the xtals in the  filter would easily guard against  that.
>
>
> <one_jump_0.907_Zoom.pdf>_____________________________________________ 
> __
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ 
> time-nuts
> and follow the instructions there.



From hmurray at megapathdsl.net  Fri Oct 24 06:46:33 2008
From: hmurray at megapathdsl.net (Hal Murray)
Date: Thu, 23 Oct 2008 23:46:33 -0700
Subject: [time-nuts] Question on crystal jumps
In-Reply-To: Message from "Steve Rooke" <sar10538@gmail.com> of "Fri,
	24 Oct 2008 15:52:42 +1300."
	<1231b6a80810231952m2f01781frc1d4d66d44bd3fd6@mail.gmail.com> 
Message-ID: <20081024064634.B3C81BCD4@ip-64-139-1-69.sjc.megapath.net>


> A lattice filter is very simple in comparison, you have the same
> voting scheme of multiple xtals (and you can have many more than
> three) but none of the complexity of the oscillator arrangement. You
> just have to make sure that it is driven with the reference standard
> and all the stages could be manually tuned for peak after a burn in.

How big are the jumps relative to the bandwidth of an individual filter stage?

If one jumps, will it be so far off that nothing gets through?

I assume crystals used in filters will age like the ones used in oscillators, 
so the "manually tuned" will really require a micro processor to keep them in 
tune.



-- 
These are my opinions, not necessarily my employer's.  I hate spam.





From rk at timing-consultants.com  Fri Oct 24 08:10:00 2008
From: rk at timing-consultants.com (Rob Kimberley)
Date: Fri, 24 Oct 2008 09:10:00 +0100
Subject: [time-nuts] OT: connector identification
In-Reply-To: <1224714343.6071.39.camel@bg-desktop>
References: <1224710605.6071.28.camel@bg-desktop><48FFA26F.2040803@bellsouth.net>
	<1224714343.6071.39.camel@bg-desktop>
Message-ID: <83795FB17C0E401DB3E4FB3BCF6EA596@Robin>

Bj?rn

The pair in the middle look like TNC (BNC with thread instead of bayonet).

Rob
-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Bj?rn Gabrielsson
Sent: 22 October 2008 23:26
To: Brian Kirby
Cc: time-nuts
Subject: Re: [time-nuts] OT: connector identification

Brian,

No its not an SMC. See attached photo. 

>From the left,

male and female SMA, female and male unkown and to the right the smaller
male SMC.

--

   Bj?rn

On Wed, 2008-10-22 at 17:00 -0500, Brian Kirby wrote:
> It may be SMC now that I looked it up.  A connector guide is attached....
> 
> 
> Bj?rn Gabrielsson wrote:
> > Hi List,
> > 
> > I have a coax connector that I would like to identify. Se attached 
> > picture.
> > 
> > To the left is a female TNC for reference. The unknown male is 
> > attached to the cable. Unknown female to the upper left as part of a "T"
adapter.
> > 
> > It looks kind of a smaller version of TNC. It is slighly larger than 
> > SMA. Female diameter is 5/16", whereas TNC is 7/16" and SMA is 4/16" 
> > - according to my simple measurement.
> > 
> > Anyone recognizing this connector?
> > 
> > thanks,
> > 
> >     Bj?rn
> > 
> > 
> > --------------------------------------------------------------------
> > ----
> > 
> > 
> > --------------------------------------------------------------------
> > ----
> > 
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to 
> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.



From SAIDJACK at aol.com  Fri Oct 24 08:33:43 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Fri, 24 Oct 2008 04:33:43 EDT
Subject: [time-nuts] Question on crystal jumps
Message-ID: <bfd.454d4117.3632e267@aol.com>

Hello Neville,
 
interesting info! Yes, chemical processing apparently can "fix" jumpy  
crystals. Wish we had more crystal processing experts post their experience  here.
 
It is interesting to note that some of these jumps on the order of say 0.1  
parts per billion or less are probably caused by only a couple of molecules  
reaching or leaving the crystal.
 
In a GPSDO, a very small change of only 0.1ppb will cause a massive change  
in phase of 50ns within 8 minutes.
 
On our Fury/FireFly GPSDO such a phase error would be arrested very quickly  
to prevent it from getting worse, and then the servo loops would push-back 
this  phase offset to 0ns over an hour or so to minimize the frequency error.
 
bye,
Said
 
 
In a message dated 10/23/2008 22:33:23 Pacific Daylight Time,  
namichie at gmail.com writes:

Does  chemical etching reduce the frequency of micro-jumps?
Can quartz crystals  be thermally annealed?
What is interesting is the ageing mechanisms. Does  gross thermal  
cycling reduce ageing?
just some  thoughts,
Neville  mIchie




From Stefan.Heinzmann at alcnetworx.de  Fri Oct 24 09:03:11 2008
From: Stefan.Heinzmann at alcnetworx.de (Heinzmann, Stefan  (ALC NetworX GmbH))
Date: Fri, 24 Oct 2008 11:03:11 +0200
Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
In-Reply-To: <E1Kt6e8-0000Rb-Kx@meow.febo.com>
References: <D7B1B5F4F3F27A4CB073BF422331203F0DD74642DD@Exchange1.lawo.de>
	<E1Kt6e8-0000Rb-Kx@meow.febo.com>
Message-ID: <D7B1B5F4F3F27A4CB073BF422331203F0DD74643CD@Exchange1.lawo.de>

Thanks, Tom!

Apart from the specifics with TimeView, how does one go about measuring ADEV with a counter that does have a dead-time? Are there tricks that can be played, either with a special measurement setup or with some data postprocessing? Or with two counters that are somehow made to cooperate?

Sorry if I'm asking the obvious, you can see that I'm a greenhorn. ;-)

Cheers
Stefan

-----Urspr?ngliche Nachricht-----
Von: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] Im Auftrag von Tom Duckworth
Gesendet: Donnerstag, 23. Oktober 2008 22:19
An: 'Discussion of precise time and frequency measurement'
Betreff: Re: [time-nuts] Measuring ADEV with a PM6681 or CNT-81

Stefan,

I am retired from Pendulum Instruments and could answer your question but I
have instead refered your question to a current engineer with the company
and you should receive an answer from them shortly. They are the experts for
this question.

Tom
Tom Duckworth
510-886-1396


-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Heinzmann, Stefan (ALC NetworX GmbH)
Sent: Thursday, October 23, 2008 10:12 AM
To: time-nuts at febo.com
Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81

Hi all,

I hope you can clear up some confusion that I have regarding ADEV
measurement. I was under the impression that you need a counter that is able
to timestamp each rising edge of the clock under test, or equivalently
measure period time continuously with no dead time. Now, while the CNT-90
can do this, the CNT-81 ( = PM6681 ) can't. Still, a message last December
to the list here
(http://www.mail-archive.com/time-nuts at febo.com/msg10963.html) seems to
indicate that using TimeView you can have ADEV plotted with the "lesser"
model, too. I have a PM6681 and TimeView, but I couldn't find out how to do
it. Maybe it can't be done.

So what's the deal on this? Can it be done, with or without TimeView, and if
yes, how? If this has been answered earlier, a link would be just fine.

Thanks and cheers
Stefan

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.


_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.


From peterawson at earthlink.net  Fri Oct 24 09:07:34 2008
From: peterawson at earthlink.net (peterawson at earthlink.net)
Date: Fri, 24 Oct 2008 11:07:34 +0200 (GMT+02:00)
Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
Message-ID: <9912770.1224839255094.JavaMail.root@elwamui-royal.atl.sa.earthlink.net>

Stefan,

When you have your question about ADEV & the PM6681 answered, would
be so kind as to share the answer with us?

Pete Rawson

-----Original Message-----
>From: Tom Duckworth <tomduck at comcast.net>
>Sent: Oct 23, 2008 10:19 PM
>To: 'Discussion of precise time and frequency measurement' <time-nuts at febo.com>
>Subject: Re: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
>
>Stefan,
>
>I am retired from Pendulum Instruments and could answer your question but I
>have instead refered your question to a current engineer with the company
>and you should receive an answer from them shortly. They are the experts for
>this question.
>
>Tom
>Tom Duckworth
>510-886-1396
> 
>
>-----Original Message-----
>From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
>Behalf Of Heinzmann, Stefan (ALC NetworX GmbH)
>Sent: Thursday, October 23, 2008 10:12 AM
>To: time-nuts at febo.com
>Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
>
>Hi all,
>
>I hope you can clear up some confusion that I have regarding ADEV
>measurement. I was under the impression that you need a counter that is able
>to timestamp each rising edge of the clock under test, or equivalently
>measure period time continuously with no dead time. Now, while the CNT-90
>can do this, the CNT-81 ( = PM6681 ) can't. Still, a message last December
>to the list here
>(http://www.mail-archive.com/time-nuts at febo.com/msg10963.html) seems to
>indicate that using TimeView you can have ADEV plotted with the "lesser"
>model, too. I have a PM6681 and TimeView, but I couldn't find out how to do
>it. Maybe it can't be done.
>
>So what's the deal on this? Can it be done, with or without TimeView, and if
>yes, how? If this has been answered earlier, a link would be just fine.
>
>Thanks and cheers
>Stefan
>
>_______________________________________________
>time-nuts mailing list -- time-nuts at febo.com
>To unsubscribe, go to
>https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>and follow the instructions there.
>
>
>_______________________________________________
>time-nuts mailing list -- time-nuts at febo.com
>To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>and follow the instructions there.



From jmiles at pop.net  Fri Oct 24 09:12:16 2008
From: jmiles at pop.net (John Miles)
Date: Fri, 24 Oct 2008 02:12:16 -0700
Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
In-Reply-To: <D7B1B5F4F3F27A4CB073BF422331203F0DD74643CD@Exchange1.lawo.de>
Message-ID: <PKEGJHPHLLBACEOICCBJGEKLNLAB.jmiles@pop.net>

Along the same lines (and this may have come up before), is there a good
Allan-deviation application for Windows that talks to the 5370B?

-- john, KE5FX

> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]On
> Behalf Of Heinzmann, Stefan (ALC NetworX GmbH)
> Sent: Friday, October 24, 2008 2:03 AM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
>
>
> Thanks, Tom!
>
> Apart from the specifics with TimeView, how does one go about
> measuring ADEV with a counter that does have a dead-time? Are
> there tricks that can be played, either with a special
> measurement setup or with some data postprocessing? Or with two
> counters that are somehow made to cooperate?
>
> Sorry if I'm asking the obvious, you can see that I'm a greenhorn. ;-)
>
> Cheers
> Stefan
>
> -----Urspr?ngliche Nachricht-----
> Von: time-nuts-bounces at febo.com
> [mailto:time-nuts-bounces at febo.com] Im Auftrag von Tom Duckworth
> Gesendet: Donnerstag, 23. Oktober 2008 22:19
> An: 'Discussion of precise time and frequency measurement'
> Betreff: Re: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
>
> Stefan,
>
> I am retired from Pendulum Instruments and could answer your
> question but I
> have instead refered your question to a current engineer with the company
> and you should receive an answer from them shortly. They are the
> experts for
> this question.
>
> Tom
> Tom Duckworth
> 510-886-1396
>
>
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
> Behalf Of Heinzmann, Stefan (ALC NetworX GmbH)
> Sent: Thursday, October 23, 2008 10:12 AM
> To: time-nuts at febo.com
> Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
>
> Hi all,
>
> I hope you can clear up some confusion that I have regarding ADEV
> measurement. I was under the impression that you need a counter
> that is able
> to timestamp each rising edge of the clock under test, or equivalently
> measure period time continuously with no dead time. Now, while the CNT-90
> can do this, the CNT-81 ( = PM6681 ) can't. Still, a message last December
> to the list here
> (http://www.mail-archive.com/time-nuts at febo.com/msg10963.html) seems to
> indicate that using TimeView you can have ADEV plotted with the "lesser"
> model, too. I have a PM6681 and TimeView, but I couldn't find out
> how to do
> it. Maybe it can't be done.
>
> So what's the deal on this? Can it be done, with or without
> TimeView, and if
> yes, how? If this has been answered earlier, a link would be just fine.
>
> Thanks and cheers
> Stefan
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



From magnus at rubidium.dyndns.org  Fri Oct 24 09:20:02 2008
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Fri, 24 Oct 2008 11:20:02 +0200
Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
In-Reply-To: <D7B1B5F4F3F27A4CB073BF422331203F0DD74643CD@Exchange1.lawo.de>
References: <D7B1B5F4F3F27A4CB073BF422331203F0DD74642DD@Exchange1.lawo.de>	<E1Kt6e8-0000Rb-Kx@meow.febo.com>
	<D7B1B5F4F3F27A4CB073BF422331203F0DD74643CD@Exchange1.lawo.de>
Message-ID: <49019342.5060502@rubidium.dyndns.org>

Heinzmann, Stefan (ALC NetworX GmbH) wrote:
> Thanks, Tom!
> 
> Apart from the specifics with TimeView, how does one go about measuring ADEV with a counter that does have a dead-time? Are there
> tricks that can be played, either with a special measurement setup or with some data postprocessing? Or with two counters that
> are somehow made to cooperate?

Consider when you compare two PPS signals. If you counter has a dead 
time of say 100 ms then it is only a certain phase relationship which 
causes the counter to miss a count if you have a counter requiring 
channel A to trigger prior to channel B (or vice versa). If you have +/- 
TI mode then channel A or B can act as a start, and then the other 
channel acts like stop. Then you can hide the dead period as it 
dynamically shifts over.

The trouble with dead time is much more annoying when you need to count 
the cycles of the signals. The PPS case does that counting without 
having dead-time, so we only need to handle the wrappings of those counters.

> Sorry if I'm asking the obvious, you can see that I'm a greenhorn. ;-)

It is a fair question.

Besides, if Tom sent the question to Staffan, then it will be a little 
while since he is on vacation.

Bj?rn has a PM6681, he can actually TRY IT. :)

Cheers,
Magnus


From bg at lysator.liu.se  Fri Oct 24 09:31:44 2008
From: bg at lysator.liu.se (=?ISO-8859-1?Q?Bj=F6rn?= Gabrielsson)
Date: Fri, 24 Oct 2008 11:31:44 +0200
Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
In-Reply-To: <49019342.5060502@rubidium.dyndns.org>
References: <D7B1B5F4F3F27A4CB073BF422331203F0DD74642DD@Exchange1.lawo.de>
	<E1Kt6e8-0000Rb-Kx@meow.febo.com>
	<D7B1B5F4F3F27A4CB073BF422331203F0DD74643CD@Exchange1.lawo.de>
	<49019342.5060502@rubidium.dyndns.org>
Message-ID: <1224840704.10741.33.camel@bg-desktop>


On Fri, 2008-10-24 at 11:20 +0200, Magnus Danielson wrote:

> Besides, if Tom sent the question to Staffan, then it will be a little 
> while since he is on vacation.
> 
> Bj?rn has a PM6681, he can actually TRY IT. :)

But I lack a GPIB solution to record any measurement series... :-(

--

   Bj?rn



From Stefan.Heinzmann at alcnetworx.de  Fri Oct 24 09:37:55 2008
From: Stefan.Heinzmann at alcnetworx.de (Heinzmann, Stefan  (ALC NetworX GmbH))
Date: Fri, 24 Oct 2008 11:37:55 +0200
Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
In-Reply-To: <49019342.5060502@rubidium.dyndns.org>
References: <D7B1B5F4F3F27A4CB073BF422331203F0DD74642DD@Exchange1.lawo.de>
	<E1Kt6e8-0000Rb-Kx@meow.febo.com>
	<D7B1B5F4F3F27A4CB073BF422331203F0DD74643CD@Exchange1.lawo.de>
	<49019342.5060502@rubidium.dyndns.org>
Message-ID: <D7B1B5F4F3F27A4CB073BF422331203F0DD7464403@Exchange1.lawo.de>

So you are proposing to do a kind of simulated time stamping by using a reference PPS signal and measure the time distance between the reference edge and the edge of the DUT? Nice idea, I'd probably need to do some math on the result to convert it to a proper timestamp, but that shouldn't be too hard. Are there tools that can do this for you? Ulrich Bangert's Plotter maybe?

The limitations of this technique, as far as I see it, are the maximum relative phase deviation of the signal under test with respect to the reference, and the limitations of the counter in terms of dead-time and trigger order. I suppose it becomes much more difficult with higher frequencies.

The PM6681 does not appear to have support for measuring time intervals in positive and negative directions at the same time. That would limit the usefulness of this trick, it seems. Or is it just as valid to use the opposite edge of one of the signals?

Cheers
Stefan


-----Urspr?ngliche Nachricht-----
Von: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] Im Auftrag von Magnus Danielson
Gesendet: Freitag, 24. Oktober 2008 11:20
An: Discussion of precise time and frequency measurement
Betreff: Re: [time-nuts] Measuring ADEV with a PM6681 or CNT-81

Heinzmann, Stefan (ALC NetworX GmbH) wrote:
> Thanks, Tom!
>
> Apart from the specifics with TimeView, how does one go about measuring ADEV with a counter that does have a dead-time? Are there
> tricks that can be played, either with a special measurement setup or with some data postprocessing? Or with two counters that
> are somehow made to cooperate?

Consider when you compare two PPS signals. If you counter has a dead
time of say 100 ms then it is only a certain phase relationship which
causes the counter to miss a count if you have a counter requiring
channel A to trigger prior to channel B (or vice versa). If you have +/-
TI mode then channel A or B can act as a start, and then the other
channel acts like stop. Then you can hide the dead period as it
dynamically shifts over.

The trouble with dead time is much more annoying when you need to count
the cycles of the signals. The PPS case does that counting without
having dead-time, so we only need to handle the wrappings of those counters.

> Sorry if I'm asking the obvious, you can see that I'm a greenhorn. ;-)

It is a fair question.

Besides, if Tom sent the question to Staffan, then it will be a little
while since he is on vacation.

Bj?rn has a PM6681, he can actually TRY IT. :)

Cheers,
Magnus

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.


From magnus at rubidium.dyndns.org  Fri Oct 24 10:09:13 2008
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Fri, 24 Oct 2008 12:09:13 +0200 (CEST)
Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
In-Reply-To: <1224840704.10741.33.camel@bg-desktop>
References: <D7B1B5F4F3F27A4CB073BF422331203F0DD74642DD@Exchange1.lawo.de>
	<E1Kt6e8-0000Rb-Kx@meow.febo.com>
	<D7B1B5F4F3F27A4CB073BF422331203F0DD74643CD@Exchange1.lawo.de>
	<49019342.5060502@rubidium.dyndns.org>
	<1224840704.10741.33.camel@bg-desktop>
Message-ID: <b7d3851416bd694530d9628356c8dd13.squirrel@rubidium.dyndns.org>

>
> On Fri, 2008-10-24 at 11:20 +0200, Magnus Danielson wrote:
>
>> Besides, if Tom sent the question to Staffan, then it will be a little
>> while since he is on vacation.
>>
>> Bj??rn has a PM6681, he can actually TRY IT. :)
>
> But I lack a GPIB solution to record any measurement series... :-(

I have a laptop with GPIB and TimeView on it. Just lacking the counter.

Cheers,
Magnus


From bruce.griffiths at xtra.co.nz  Fri Oct 24 12:43:48 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Sat, 25 Oct 2008 01:43:48 +1300
Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
In-Reply-To: <D7B1B5F4F3F27A4CB073BF422331203F0DD7464403@Exchange1.lawo.de>
References: <D7B1B5F4F3F27A4CB073BF422331203F0DD74642DD@Exchange1.lawo.de>	<E1Kt6e8-0000Rb-Kx@meow.febo.com>	<D7B1B5F4F3F27A4CB073BF422331203F0DD74643CD@Exchange1.lawo.de>	<49019342.5060502@rubidium.dyndns.org>
	<D7B1B5F4F3F27A4CB073BF422331203F0DD7464403@Exchange1.lawo.de>
Message-ID: <4901C304.2000401@xtra.co.nz>

Heinzmann, Stefan (ALC NetworX GmbH) wrote:
> So you are proposing to do a kind of simulated time stamping by using a reference PPS signal and measure the time distance between the reference edge and the edge of the DUT? Nice idea, I'd probably need to do some math on the result to convert it to a proper timestamp, but that shouldn't be too hard. Are there tools that can do this for you? Ulrich Bangert's Plotter maybe?
>
> The limitations of this technique, as far as I see it, are the maximum relative phase deviation of the signal under test with respect to the reference, and the limitations of the counter in terms of dead-time and trigger order. I suppose it becomes much more difficult with higher frequencies.
>
> The PM6681 does not appear to have support for measuring time intervals in positive and negative directions at the same time. That would limit the usefulness of this trick, it seems. Or is it just as valid to use the opposite edge of one of the signals?
>
> Cheers
> Stefan
>
>
> Heinzmann, Stefan (ALC NetworX GmbH) wrote:
>   
>> Thanks, Tom!
>>
>> Apart from the specifics with TimeView, how does one go about measuring ADEV with a counter that does have a dead-time? Are there
>> tricks that can be played, either with a special measurement setup or with some data postprocessing? Or with two counters that
>> are somehow made to cooperate?
>>     
>
> Consider when you compare two PPS signals. If you counter has a dead
> time of say 100 ms then it is only a certain phase relationship which
> causes the counter to miss a count if you have a counter requiring
> channel A to trigger prior to channel B (or vice versa). If you have +/-
> TI mode then channel A or B can act as a start, and then the other
> channel acts like stop. Then you can hide the dead period as it
> dynamically shifts over.
>
> The trouble with dead time is much more annoying when you need to count
> the cycles of the signals. The PPS case does that counting without
> having dead-time, so we only need to handle the wrappings of those counters.
>
>   
>> Sorry if I'm asking the obvious, you can see that I'm a greenhorn. ;-)
>>     
>
> It is a fair question.
>
> Besides, if Tom sent the question to Staffan, then it will be a little
> while since he is on vacation.
>
> Bj?rn has a PM6681, he can actually TRY IT. :)
>
> Cheers,
> Magnus
>
>   
Why not just use Greenhall's picket fence technique which was devised to
allow timestamping of a signal despite the time interval counter having
a finite deadtime?
Use the leading edge of the PPS signal to start the time interval
counter and stop the time interval counter on the next zero crossing of
say a 10Hz, 100Hz, or even a 1KHz signal derived from the  local
frequency standard?
Since the largest time interval to be measured is 100ms, 10ms or 1ms
depending on the STOP channel frequency, counter deadtime is not a problem.

Details are given in the paper:
http://horology.jpl.nasa.gov/papers/picket_uffc.pdf

Bruce




From Stefan.Heinzmann at alcnetworx.de  Fri Oct 24 13:31:18 2008
From: Stefan.Heinzmann at alcnetworx.de (Heinzmann, Stefan  (ALC NetworX GmbH))
Date: Fri, 24 Oct 2008 15:31:18 +0200
Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
In-Reply-To: <4901C304.2000401@xtra.co.nz>
References: <D7B1B5F4F3F27A4CB073BF422331203F0DD74642DD@Exchange1.lawo.de>
	<E1Kt6e8-0000Rb-Kx@meow.febo.com>
	<D7B1B5F4F3F27A4CB073BF422331203F0DD74643CD@Exchange1.lawo.de>
	<49019342.5060502@rubidium.dyndns.org>
	<D7B1B5F4F3F27A4CB073BF422331203F0DD7464403@Exchange1.lawo.de>
	<4901C304.2000401@xtra.co.nz>
Message-ID: <D7B1B5F4F3F27A4CB073BF422331203F0DD74644C0@Exchange1.lawo.de>

The picket fence technique indeed seems like an interesting solution. The one thing that made me concerned is the problem of detecting missing data. The detection seems to be hardest when the frequency of the DUT is a submultiple of the picket fence frequency, which is what your examples amount to. So I wonder: Would it be better to use a noninteger picket frequency if one wants to measure PPS signals?

Cheers
Stefan


-----Urspr?ngliche Nachricht-----
Von: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] Im Auftrag von Bruce Griffiths
Gesendet: Freitag, 24. Oktober 2008 14:44
An: Discussion of precise time and frequency measurement
Betreff: Re: [time-nuts] Measuring ADEV with a PM6681 or CNT-81

Heinzmann, Stefan (ALC NetworX GmbH) wrote:
> So you are proposing to do a kind of simulated time stamping by using a reference PPS signal and measure the time distance between the reference edge and the edge of the DUT? Nice idea, I'd probably need to do some math on the result to convert it to a proper timestamp, but that shouldn't be too hard. Are there tools that can do this for you? Ulrich Bangert's Plotter maybe?
>
> The limitations of this technique, as far as I see it, are the maximum relative phase deviation of the signal under test with respect to the reference, and the limitations of the counter in terms of dead-time and trigger order. I suppose it becomes much more difficult with higher frequencies.
>
> The PM6681 does not appear to have support for measuring time intervals in positive and negative directions at the same time. That would limit the usefulness of this trick, it seems. Or is it just as valid to use the opposite edge of one of the signals?

>
> Cheers
> Stefan
>
>
> Heinzmann, Stefan (ALC NetworX GmbH) wrote:
>
>> Thanks, Tom!
>>
>> Apart from the specifics with TimeView, how does one go about measuring ADEV with a counter that does have a dead-time? Are there
>> tricks that can be played, either with a special measurement setup or with some data postprocessing? Or with two counters that
>> are somehow made to cooperate?
>>
>
> Consider when you compare two PPS signals. If you counter has a dead
> time of say 100 ms then it is only a certain phase relationship which
> causes the counter to miss a count if you have a counter requiring
> channel A to trigger prior to channel B (or vice versa). If you have +/-
> TI mode then channel A or B can act as a start, and then the other
> channel acts like stop. Then you can hide the dead period as it
> dynamically shifts over.
>
> The trouble with dead time is much more annoying when you need to count
> the cycles of the signals. The PPS case does that counting without
> having dead-time, so we only need to handle the wrappings of those counters.
>
>
>> Sorry if I'm asking the obvious, you can see that I'm a greenhorn. ;-)
>>
>
> It is a fair question.
>
> Besides, if Tom sent the question to Staffan, then it will be a little
> while since he is on vacation.
>
> Bj?rn has a PM6681, he can actually TRY IT. :)
>
> Cheers,
> Magnus
>
>
Why not just use Greenhall's picket fence technique which was devised to
allow timestamping of a signal despite the time interval counter having
a finite deadtime?
Use the leading edge of the PPS signal to start the time interval
counter and stop the time interval counter on the next zero crossing of
say a 10Hz, 100Hz, or even a 1KHz signal derived from the  local
frequency standard?
Since the largest time interval to be measured is 100ms, 10ms or 1ms
depending on the STOP channel frequency, counter deadtime is not a problem.

Details are given in the paper:
http://horology.jpl.nasa.gov/papers/picket_uffc.pdf

Bruce



_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.


From cdreher at sta.samsung.com  Fri Oct 24 13:57:16 2008
From: cdreher at sta.samsung.com (Carl Dreher)
Date: Fri, 24 Oct 2008 08:57:16 -0500
Subject: [time-nuts] time-nuts Digest, Vol 51, Issue 80
In-Reply-To: <mailman.5.1224849601.23136.time-nuts@febo.com>
References: <mailman.5.1224849601.23136.time-nuts@febo.com>
Message-ID: <64260ABC228BC44AA5A9BE082AF4AAB6022B237A@mx2.telecom.sna.samsung.com>

Hi,

Just wondered how many people on this list are also members of the
Horological Sciences chapter of the NAWCC?

Carl Dreher


From wje at quackers.net  Fri Oct 24 14:01:30 2008
From: wje at quackers.net (wje)
Date: Fri, 24 Oct 2008 10:01:30 -0400
Subject: [time-nuts] My HP 10638A degausser replacement for the 5061A
Message-ID: <4901D53A.4060603@quackers.net>

I've finished my degausser replacement. I've put a zip file with 
schematics, pcb layout, a picture of the finished unit, etc. on my ftp site.

Note that you have to use ftp to get to it, not a web browser:

ftp ftp.quackers.net
login: ftp at quackers.net

Use the login name exactly as given. Just hit enter at the password prompt.

Get degausser.zip.

-- 
Bill Ezell
----------
They said 'Windows or better'
so I used Linux.



From ernieperes at aol.com  Fri Oct 24 14:17:22 2008
From: ernieperes at aol.com (ernieperes at aol.com)
Date: Fri, 24 Oct 2008 10:17:22 -0400
Subject: [time-nuts] Trimble Rodal Antenna
In-Reply-To: <48F99265.8060108@blob.demon.co.uk>
References: <48F99265.8060108@blob.demon.co.uk>
Message-ID: <8CB03FA5D95DF9D-17E4-71@webmail-md17.sysops.aol.com>


Hello Genst,

Anybody has info/datasheet, pinout  / 7 pin / of this Trimble Rodal 
Antenna, P/N  240066-32..?????
Thanks  for your help.

Rgds Ernie.


From rdarlington at gmail.com  Fri Oct 24 14:32:52 2008
From: rdarlington at gmail.com (Robert Darlington)
Date: Fri, 24 Oct 2008 08:32:52 -0600
Subject: [time-nuts] My HP 10638A degausser replacement for the 5061A
In-Reply-To: <4901D53A.4060603@quackers.net>
References: <4901D53A.4060603@quackers.net>
Message-ID: <b3bd5fcb0810240732w4e15c5aetcdc9453aec9ea005@mail.gmail.com>

For those of us that use Firefox (and possibly some others), you can get to
it via the web with this URL:

ftp://ftp at quackers.net:x at ftp.quackers.net/

-Bob

On Fri, Oct 24, 2008 at 8:01 AM, wje <wje at quackers.net> wrote:

> I've finished my degausser replacement. I've put a zip file with
> schematics, pcb layout, a picture of the finished unit, etc. on my ftp
> site.
>
> Note that you have to use ftp to get to it, not a web browser:
>
> ftp ftp.quackers.net
> login: ftp at quackers.net
>
> Use the login name exactly as given. Just hit enter at the password prompt.
>
> Get degausser.zip.
>
> --
> Bill Ezell
> ----------
> They said 'Windows or better'
> so I used Linux.
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

From javier.serrano.pareja at gmail.com  Fri Oct 24 14:50:05 2008
From: javier.serrano.pareja at gmail.com (Javier Serrano)
Date: Fri, 24 Oct 2008 16:50:05 +0200
Subject: [time-nuts] OT: Open Hardware Repository
In-Reply-To: <f616e0f80810232126p66f686b5vc11998151a576958@mail.gmail.com>
References: <83e48fa10810220119n3d3d6df6r348efc68ddca5d17@mail.gmail.com>
	<f616e0f80810232126p66f686b5vc11998151a576958@mail.gmail.com>
Message-ID: <83e48fa10810240750j7f0d27ebsdda59939e7b9a02f@mail.gmail.com>

I'd say before the end of the year. If you have any suggestion on the specs
I am all ears.
Cheers,
Javier

On Fri, Oct 24, 2008 at 6:26 AM, Jim Palfreyman <jim77742 at gmail.com> wrote:

> I like it. When is it ready?
>
> Jim
>
>
> 2008/10/22 Javier Serrano <javier.serrano.pareja at gmail.com>
>
> > Dear nuts,
> >
> > Sorry for this posting, only indirectly related to timing. For a long
> time
> > I've been toying with the idea of a web-based Open Hardware Repository,
> and
> > now it looks like we could allocate some resources to building it. Here
> are
> > some preliminary and unofficial specs:
> >
> >
> http://ab-dep-co-ht.web.cern.ch/ab-dep-co-ht/documents/2008/Hardware/OHRFuncSpec.pdf
> > .
> > I have not found anywhere a kind of repository which would match these
> > requirements completely. It's intended to be for PCB design, in a much
> more
> > humble scale, what source forge is for software or opencores.org is for
> > HDL.
> > Since many of the designs we'd put there are timing-related, I thought
> I'd
> > ask you for feedback:
> > - Do you think this is a good idea?
> > - Does this exist already somewhere?
> > - Any comments on the specs?
> > Feel free to answer directly to me if you think this is really off topic.
> I
> > would not like to spoil the fine SNR of this list. If I see there's lots
> of
> > interest I will post a summary.
> >
> > Thanks,
> >
> > Javier
> > _______________________________________________
> > time-nuts mailing list -- time-nuts at febo.com
> > To unsubscribe, go to
> > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> > and follow the instructions there.
> >
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

From SAIDJACK at aol.com  Fri Oct 24 16:02:45 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Fri, 24 Oct 2008 12:02:45 EDT
Subject: [time-nuts] Question on crystal jumps
Message-ID: <c57.44dcafe2.36334ba5@aol.com>

Hi Antonio,
 
the X axis is in 6 second steps. This jump happened after days of perfect  
lock. Happened out of the blue, random (Poisson as someone had said? :)  
distribution.
 

From bogus@does.not.exist.com  Fri Oct 24 14:17:43 2008
From: bogus@does.not.exist.com ()
Date: Fri, 24 Oct 2008 14:17:43 -0000
Subject: No subject
Message-ID: <mailman.0.1224864170.2458.time-nuts@febo.com>

seen their GPSDO's, Pendulums, etc jump after long times like this,  
sometimes after weeks of perfect operation.
 
bye,
Said
 
 
In a message dated 10/24/2008 06:29:34 Pacific Daylight Time,  iovane@
inwind.it writes:

> See  the following plot, blue is phase offset to UTC, brown is EFC   
voltage.

Said,
please, what is on the X axis? When did this jump  occur?

Thanks,
Antonio  I8IOV





From ka2cdk at cox.net  Fri Oct 24 19:59:53 2008
From: ka2cdk at cox.net (Thomas A. Frank)
Date: Fri, 24 Oct 2008 15:59:53 -0400
Subject: [time-nuts] time-nuts Digest, Vol 51, Issue 80
In-Reply-To: <64260ABC228BC44AA5A9BE082AF4AAB6022B237A@mx2.telecom.sna.samsung.com>
References: <mailman.5.1224849601.23136.time-nuts@febo.com>
	<64260ABC228BC44AA5A9BE082AF4AAB6022B237A@mx2.telecom.sna.samsung.com>
Message-ID: <723DF858-F50D-4F11-A255-523C1290054F@cox.net>

Hi Carl;

I am.

Tom Frank, KA2CDK

On Oct 24, 2008, at 9:57 AM, Carl Dreher wrote:

> Hi,
>
> Just wondered how many people on this list are also members of the
> Horological Sciences chapter of the NAWCC?
>
> Carl Dreher
>


From bruce.griffiths at xtra.co.nz  Fri Oct 24 20:07:45 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Sat, 25 Oct 2008 09:07:45 +1300
Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
In-Reply-To: <D7B1B5F4F3F27A4CB073BF422331203F0DD74644C0@Exchange1.lawo.de>
References: <D7B1B5F4F3F27A4CB073BF422331203F0DD74642DD@Exchange1.lawo.de>	<E1Kt6e8-0000Rb-Kx@meow.febo.com>	<D7B1B5F4F3F27A4CB073BF422331203F0DD74643CD@Exchange1.lawo.de>	<49019342.5060502@rubidium.dyndns.org>	<D7B1B5F4F3F27A4CB073BF422331203F0DD7464403@Exchange1.lawo.de>	<4901C304.2000401@xtra.co.nz>
	<D7B1B5F4F3F27A4CB073BF422331203F0DD74644C0@Exchange1.lawo.de>
Message-ID: <49022B11.6060003@xtra.co.nz>

Heinzmann, Stefan (ALC NetworX GmbH) wrote:
> The picket fence technique indeed seems like an interesting solution. The one thing that made me concerned is the problem of detecting missing data. The detection seems to be hardest when the frequency of the DUT is a submultiple of the picket fence frequency, which is what your examples amount to. So I wonder: Would it be better to use a noninteger picket frequency if one wants to measure PPS signals?
>
> Cheers
> Stefan
>
>
>   
Stefan

I presume you are referring to missing PPS pulses from a GPS receiver.
In this case with a timing GPS receiver logging the timestamp associated
with each PPS pulse should allow you to detect missing PPS pulses.
The M12+T and M12M -T timing receivers can make this data available.
Otherwise very coarse time stamping is more than sufficient to detect
missing PPS pulses.
Such time stamping can easily be done with a PC.

Bruce



From iovane at inwind.it  Fri Oct 24 20:25:55 2008
From: iovane at inwind.it (iovane at inwind.it)
Date: Fri, 24 Oct 2008 22:25:55 +0200
Subject: [time-nuts] Question on crystal jumps
Message-ID: <K99FF7$9035DDBEF82B787A35E1E41F7B59FB56@libero.it>

Thanks, Said.

What seldom happens to my tuning forks is similar to your 
brown line, of course.
Do you have date and time of this beatiful jump?
Have you observed, by chance, a negative (restoring) jump at any time after this jump?
(the sense of the latter question is that, if you observed a 
restoring jump one would think of metastability (whatever the
triggering cause), if you didn't happen then both of the 
possibilities remain open, that is metastability and 
permanent modifications in the crystal as pointed out by 
Neville).

Antonio I8IOV

> Hi Antonio,
>  
> the X axis is in 6 second steps. This jump happened after days of perfect  
> lock. Happened out of the blue, random (Poisson as someone had said? :)  
> distribution.
>  
> From what I can see from the very interesting email thread, other users  have 
> seen their GPSDO's, Pendulums, etc jump after long times like this,  
> sometimes after weeks of perfect operation.
>  
> bye,
> Said
>  
>  
> In a message dated 10/24/2008 06:29:34 Pacific Daylight Time,  iovane@
> inwind.it writes:
> 
> > See  the following plot, blue is phase offset to UTC, brown is EFC   
> voltage.
> 
> Said,
> please, what is on the X axis? When did this jump  occur?
> 
> Thanks,
> Antonio  I8IOV




From namichie at gmail.com  Fri Oct 24 20:42:44 2008
From: namichie at gmail.com (Neville Michie)
Date: Sat, 25 Oct 2008 07:42:44 +1100
Subject: [time-nuts] time-nuts Digest, Vol 51, Issue 80
In-Reply-To: <723DF858-F50D-4F11-A255-523C1290054F@cox.net>
References: <mailman.5.1224849601.23136.time-nuts@febo.com>
	<64260ABC228BC44AA5A9BE082AF4AAB6022B237A@mx2.telecom.sna.samsung.com>
	<723DF858-F50D-4F11-A255-523C1290054F@cox.net>
Message-ID: <FEA7A119-40BB-4612-9938-1B03CBD0DFA7@gmail.com>

hi Tom and Frank,
I am a member of NAWCC, and the Sydney Clockmakers Society.
cheers, Neville Michie

On 25/10/2008, at 6:59 AM, Thomas A. Frank wrote:

> Hi Carl;
>
> I am.
>
> Tom Frank, KA2CDK
>
> On Oct 24, 2008, at 9:57 AM, Carl Dreher wrote:
>
>> Hi,
>>
>> Just wondered how many people on this list are also members of the
>> Horological Sciences chapter of the NAWCC?
>>
>> Carl Dreher
>>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ 
> time-nuts
> and follow the instructions there.



From SAIDJACK at aol.com  Fri Oct 24 21:54:13 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Fri, 24 Oct 2008 17:54:13 EDT
Subject: [time-nuts] Question on crystal jumps
Message-ID: <d38.37912c27.36339e05@aol.com>

Hi Antonio,
 
no restoring jump happened within a couple of days from that jump. I think  
it's permanent.
 
Unfortunately I don't have a date/time for this jump.
 
The best resource for dated graphical data is probably realhamradio's  GPSCon 
links, even though half of those links seem to have been last updated  years 
ago :)
 
   _http://www.realhamradio.com/GPS_websites_list.htm_ 
(http://www.realhamradio.com/GPS_websites_list.htm) 
 
You can see a pre-production Fury on there at the Universidad de Colima,  
it's a notorious jumper. It will be quiet for weeks, then jump significantly for  
some time. They don't want to have the unit replaced with a good one  though, 
which makes for interesting reading.
 
bye,
Said
 
 
In a message dated 10/24/2008 13:28:43 Pacific Daylight Time,  
iovane at inwind.it writes:

Thanks,  Said.

What seldom happens to my tuning forks is similar to your  
brown line, of course.
Do you have date and time of this beatiful  jump?
Have you observed, by chance, a negative (restoring) jump at any time  after 
this jump?
(the sense of the latter question is that, if you observed  a 
restoring jump one would think of metastability (whatever  the
triggering cause), if you didn't happen then both of the  
possibilities remain open, that is metastability and 
permanent  modifications in the crystal as pointed out by 
Neville).

Antonio  I8IOV



From hmurray at megapathdsl.net  Fri Oct 24 23:40:28 2008
From: hmurray at megapathdsl.net (Hal Murray)
Date: Fri, 24 Oct 2008 16:40:28 -0700
Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
In-Reply-To: Message from "Heinzmann, Stefan (ALC NetworX GmbH)" 
	<Stefan.Heinzmann@alcnetworx.de> of "Fri,
	24 Oct 2008 11:37:55 +0200."
	<D7B1B5F4F3F27A4CB073BF422331203F0DD7464403@Exchange1.lawo.de> 
Message-ID: <20081024234029.030AFBCD4@ip-64-139-1-69.sjc.megapath.net>


> The PM6681 does not appear to have support for measuring time
> intervals in positive and negative directions at the same time. That
> would limit the usefulness of this trick, it seems. Or is it just as
> valid to use the opposite edge of one of the signals? 

Will a long chunk of coax shift one signal far enough so you can be sure of 
the order?


-- 
These are my opinions, not necessarily my employer's.  I hate spam.





From magnus at rubidium.dyndns.org  Sat Oct 25 00:04:36 2008
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Sat, 25 Oct 2008 02:04:36 +0200
Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
In-Reply-To: <20081024234029.030AFBCD4@ip-64-139-1-69.sjc.megapath.net>
References: <20081024234029.030AFBCD4@ip-64-139-1-69.sjc.megapath.net>
Message-ID: <49026294.7040606@rubidium.dyndns.org>

Hal Murray wrote:
>> The PM6681 does not appear to have support for measuring time
>> intervals in positive and negative directions at the same time. That
>> would limit the usefulness of this trick, it seems. Or is it just as
>> valid to use the opposite edge of one of the signals? 
> 
> Will a long chunk of coax shift one signal far enough so you can be sure of 
> the order?

No. Consider a low frequency difference, and you will slowly shift 
through all phase relationships. You need to handle them all without 
dropping a measurement.

Cheers,
Magnus


From tomduck at comcast.net  Sat Oct 25 01:10:57 2008
From: tomduck at comcast.net (Tom Duckworth)
Date: Fri, 24 Oct 2008 18:10:57 -0700
Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
In-Reply-To: <D7B1B5F4F3F27A4CB073BF422331203F0DD74643CD@Exchange1.lawo.de>
Message-ID: <mailman.1.1224897061.2458.time-nuts@febo.com>

Stefan,

 

Well, I have been sort of staying out of the recent discussions regarding
oscillator stability measurements, ADEV, etc., but here goes my two cents
worth. I hope it doesn't muddy the waters too much and is somewhat helpful.

 

There is a fundamental problem with trying to do ADEV (Allan Deviation) with
a counter that has a gated measurement engine (all standard counters). The
problem is that when the count engine gate closes (so the counter can
compute the number of events, report the result as a frequency, and clear
its registers), the counter is blind (dead time) to any signal at the input.
Allan deviation REQUIRES than a minimum number of measurements be made
back-to-back (no dead time between measurements) in order to capture
nondeterministic fluctuations of the signal you're trying to measure. This
requires a measuring device (counter) that continuously records ALL events.
It does this by time-stamping a fixed period in a separate register in the
counter along with the input register (the signal being measured), and a
time-base register that records the frequency the signal is to be compared
with. There is no ?gate? as such in a time-stamping counter.

 

Most stability measurements, longer than say 100 seconds, are made in the
frequency domain because energy changes, as a result of heat, are by far the
predominate cause of stability (aging) issues (see below). Stability issues
within shorter time periods, say <100 sec., are often nondeterministic, and
cannot be accurately quantified in the frequency domain, but must be
measured in the time domain, using statistical weighting. In other words,
unpredictable, and often little understood, events (Shot and thermal noise
in the active devices, random variations in the frequency-determining
elements, cosmic rays, etc.) often predominate short term stability
measurements and must be described statistically, as their occurrence and
duration are random. Allan deviation is a widely accepted time-domain
statistical measurement whose calculated results compare well with the more
common frequency domain measurement of longer time periods.

 

Allan deviation measurements are based on the sample variance of the
fractional-frequency fluctuations. Without specifying the number of samples
N, and the repetition interval T, for measurements of duration t, the
measure of frequency stability is dimensionless and would converge to a
meaningless limit. Secondly, some actual noise processes contain substantial
fractions of the total noise power in the instantaneous fractional-frequency
range below one cycle per year. In order to improve compatibility of data,
it is important to specify a particular N and T. The Allan variance chooses
N=2 and T=t (i.e. no dead time between measurements). A good estimate can be
obtained by a limited number, m, of measurements (m=*100). Root Allen
variance is expressed as a quantity divided by the square of the
measurements of duration t, (i.e., 3 x 10-11/*t).

.

Classical variance diverges for commonly observed noise processes, such as
random walk (i.e., the variance increases with an increasing number of data
points). The advantage with the Allan variance is that it:

?           converges for all noise processes observed in precision
oscillators;

?           has straightforward relationship to power law spectral density
(spectral density of the frequency fluctuations);

?           is easy to compute, and;

?           is faster and more accurate in estimating noise processes than
the Fast Fourier Transform.

 

Aging in quartz crystal oscillators is caused by changes in either the
quartz crystal itself or the associated components found in the oscillator
assembly. Aging is the result of a combination of several factors having
complex, and only partially understood, components that effect the aging
specification. Effects can include the cut (orientation) of the crystal;
vibration modes; frequency of cut size; temperature of operation and
variations of temperature; drive energy; gravity; physical orientation;
shock; electromagnetic interference; diffusion of impurities and the
outgassing of the quartz crystal; the glass or ceramic base; the adhesive
used to mount the quartz; metal migration from the electrodes into the
quartz surface; stress relief of the crystal mounts; changes of electric
component values over time; and, voltage regulation.

 

This is probably more information than you really wanted, but oh well,
enjoy. 

 

Tom

Tom Duckworth

510-886-1396

 

 

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Heinzmann, Stefan (ALC NetworX GmbH)
Sent: Friday, October 24, 2008 2:03 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Measuring ADEV with a PM6681 or CNT-81

 

Thanks, Tom!

 

Apart from the specifics with TimeView, how does one go about measuring ADEV
with a counter that does have a dead-time? Are there tricks that can be
played, either with a special measurement setup or with some data
postprocessing? Or with two counters that are somehow made to cooperate?

 

Sorry if I'm asking the obvious, you can see that I'm a greenhorn. ;-)

 

Cheers

Stefan

 

-----Urspr?ngliche Nachricht-----

Von: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] Im
Auftrag von Tom Duckworth

Gesendet: Donnerstag, 23. Oktober 2008 22:19

An: 'Discussion of precise time and frequency measurement'

Betreff: Re: [time-nuts] Measuring ADEV with a PM6681 or CNT-81

 

Stefan,

 

I am retired from Pendulum Instruments and could answer your question but I

have instead refered your question to a current engineer with the company

and you should receive an answer from them shortly. They are the experts for

this question.

 

Tom

Tom Duckworth

510-886-1396

 

 

-----Original Message-----

From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On

Behalf Of Heinzmann, Stefan (ALC NetworX GmbH)

Sent: Thursday, October 23, 2008 10:12 AM

To: time-nuts at febo.com

Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81

 

Hi all,

 

I hope you can clear up some confusion that I have regarding ADEV

measurement. I was under the impression that you need a counter that is able

to timestamp each rising edge of the clock under test, or equivalently

measure period time continuously with no dead time. Now, while the CNT-90

can do this, the CNT-81 ( = PM6681 ) can't. Still, a message last December

to the list here

(http://www.mail-archive.com/time-nuts at febo.com/msg10963.html) seems to

indicate that using TimeView you can have ADEV plotted with the "lesser"

model, too. I have a PM6681 and TimeView, but I couldn't find out how to do

it. Maybe it can't be done.

 

So what's the deal on this? Can it be done, with or without TimeView, and if

yes, how? If this has been answered earlier, a link would be just fine.

 

Thanks and cheers

Stefan

 

_______________________________________________

time-nuts mailing list -- time-nuts at febo.com

To unsubscribe, go to

https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

and follow the instructions there.

 

 

_______________________________________________

time-nuts mailing list -- time-nuts at febo.com

To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

and follow the instructions there.

 

_______________________________________________

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To unsubscribe, go to
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and follow the instructions there.


From pico.2008 at sbcglobal.net  Sat Oct 25 19:30:25 2008
From: pico.2008 at sbcglobal.net (Peter Putnam)
Date: Sat, 25 Oct 2008 12:30:25 -0700
Subject: [time-nuts] How to get 32.768KHz from 10MHz.
In-Reply-To: <002301c8ecdc$8ee4aad0$0900a8c0@pc52>
References: <00b901c8eccd$b95782b0$7300a8c0@p4253>	<20080723143304.18A811165C3@hamburg.alientech.net>
	<002301c8ecdc$8ee4aad0$0900a8c0@pc52>
Message-ID: <490373D1.7060401@sbcglobal.net>


For those still interested in the 10 MHz to 32 KHz divider issue, I
offer the PIC source to a tested divider that runs in an 8-pin DIP
package device:

http://www.ni6e.com/time/10M32K.html

Regards,
Peter



Tom Van Baak wrote:
> Since synchronization is more important than jitter in this
> application it's easy to generate 32 kHz from 10 MHz.
>
> A 10 MHz clock into a PIC gives a 400 ns/instruction time.
>
> To produce 32.768 kHz you flip an output pin put every 38
> instructions, except that 9632 times per second you make
> it 39 instructions instead.
>
> The result is 65536 bit flips per second (giving a frequency
> of exactly 32768 Hz) consuming 2 500 000 instructions per
> second. The output accuracy equals the input accuracy.
> The output jitter is as most 400 ns.
>
> /tvb
>
>   



From BriMDavis at aol.com  Sat Oct 25 20:47:41 2008
From: BriMDavis at aol.com (BriMDavis at aol.com)
Date: Sat, 25 Oct 2008 16:47:41 EDT
Subject: [time-nuts] How to get 32.768KHz from 10MHz.
Message-ID: <ce6.3b74312b.3634dfed@aol.com>

>
> A 10 MHz clock into a PIC gives a 400 ns/instruction time.
>
> To produce 32.768 kHz you flip an output pin put every 38
> instructions, except that 9632 times per second you make
> it 39 instructions instead.
>
 
To figure out those sorts of ratios for static frequency dividers,
Allan Herriman has written a nifty fractional divider script that
generates VHDL/Verilog code for CPLD/FPGA applications:

http://fractional-divider.tripod.com/

It will generate dual modulus or phase accumulator
based dividers, with various implementation options.

To generate a 10 Mhz to 32.768 Khz with a frequency error
tolerance of 1e-12 :

fracn09.pl  -t 1e-12  10e6  32768

Which generates a file "fracn.vhd":
<snip>
--
-- Frequency Results (use_phase_accumulator = FALSE) :
--  Achieved Output Frequency: 32768 Hz.
--  Achieved Relative Frequency Error: 0 (0 ppm)
--  Achieved Frequency Error: 0 Hz.
--
<snip>

constant n              : positive := 305;  -- prescaler divides by n or n + 1
constant a              : positive := 211;  -- this many counts of 305
constant b              : natural  := 45;   -- this many counts of 306

<snip>
--
-- Design Parameters (use_phase_accumulator = FALSE) :
--  Approx 20 flip flops (9 in prescaler, 9 in controller and 2 retimes).
--  The recursive controller uses approx 17 flip flops.
--  The Dual-Modulus Prescaler uses ratios /305,/306
--  The Output consists of 211 cycles of 305 input clocks,
--  and 45 cycles of 306 input clocks.
--  There are 256 output clocks for every 78125 input clocks.
--
 
 
Brian
 
 
**************A Good Credit Score is 700 or Above. See yours in just 2 easy 
steps! 
(http://pr.atwola.com/promoclk/100000075x1211625659x1200715650/aol?redir=http://www.freecreditreport.com/pm/default.aspx?sc=668072&hmpgID=82&bcd=emailf
ooter)


From jmiles at pop.net  Sun Oct 26 02:22:14 2008
From: jmiles at pop.net (John Miles)
Date: Sat, 25 Oct 2008 19:22:14 -0700
Subject: [time-nuts] Looking for HP 5062C manual
Message-ID: <PKEGJHPHLLBACEOICCBJCELONMAB.jmiles@pop.net>

Anyone got a .PDF of the 5062C op/service manual, before I fall back to
Manuals Plus?

-- john, KE5FX



From gretchendenisebaxter at gmail.com  Sun Oct 26 02:44:54 2008
From: gretchendenisebaxter at gmail.com (Gretchen Baxter)
Date: Sat, 25 Oct 2008 22:44:54 -0400
Subject: [time-nuts] How can it be :05 in one place and :30 in another
Message-ID: <4fdb424f0810251944t2a19ebaaw92bff5efc423bc03@mail.gmail.com>

Hi,

I went to http://www.timeanddate.com/worldclock/

I saw that it was 10:35 in New York but in Adelaide it was 1:05 PM and in
New Delhi 8:05.

How can that be?

Gretchen

From imp at bsdimp.com  Sun Oct 26 02:48:21 2008
From: imp at bsdimp.com (Warner Losh)
Date: Sat, 25 Oct 2008 20:48:21 -0600 (MDT)
Subject: [time-nuts] How can it be :05 in one place and :30 in another
In-Reply-To: <4fdb424f0810251944t2a19ebaaw92bff5efc423bc03@mail.gmail.com>
References: <4fdb424f0810251944t2a19ebaaw92bff5efc423bc03@mail.gmail.com>
Message-ID: <20081025.204821.71120900.imp@bsdimp.com>

From: "Gretchen Baxter" <gretchendenisebaxter at gmail.com>
Subject: [time-nuts] How can it be :05 in one place and :30 in another
Date: Sat, 25 Oct 2008 22:44:54 -0400

> Hi,
> 
> I went to http://www.timeanddate.com/worldclock/
> 
> I saw that it was 10:35 in New York but in Adelaide it was 1:05 PM and in
> New Delhi 8:05.
> 
> How can that be?

1/2 hour offset timezones are more common than you think.

Warner


From rmoncur at bigpond.net.au  Sun Oct 26 02:51:06 2008
From: rmoncur at bigpond.net.au (Rex Moncur)
Date: Sun, 26 Oct 2008 13:51:06 +1100
Subject: [time-nuts] How can it be :05 in one place and :30 in another
In-Reply-To: <4fdb424f0810251944t2a19ebaaw92bff5efc423bc03@mail.gmail.com>
Message-ID: <20081026025106.DSUQ15831.nschwotgx01p.mx.bigpond.com@REX740>

Gretchen

Adelaide (South Australia) has a half hour time difference to Eastern
Australian Time. These things are caused by having a Federation of States
where the States make their own laws about time.

Rex VK7MO

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Gretchen Baxter
Sent: Sunday, 26 October 2008 1:45 PM
To: Discussion of precise time and frequency measurement
Subject: [time-nuts] How can it be :05 in one place and :30 in another

Hi,

I went to http://www.timeanddate.com/worldclock/

I saw that it was 10:35 in New York but in Adelaide it was 1:05 PM and in
New Delhi 8:05.

How can that be?

Gretchen
_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



From N3IZN at aol.com  Sun Oct 26 02:55:57 2008
From: N3IZN at aol.com (N3IZN at aol.com)
Date: Sat, 25 Oct 2008 22:55:57 EDT
Subject: [time-nuts] How can it be :05 in one place and :30 in another
Message-ID: <c4e.447b433e.3635363d@aol.com>

Yep what he said, check Tehran also


**************
A Good Credit Score is 700 
or Above. See yours in just 2 easy steps! 
(http://pr.atwola.com/promoclk/100000075x1211625659x1200715650/aol?redir=http://www.freecreditreport.com/pm/default.
aspx?sc=668072&amp;hmpgID=82&amp;bcd=emailfooter)

From gretchendenisebaxter at gmail.com  Sun Oct 26 03:13:04 2008
From: gretchendenisebaxter at gmail.com (Gretchen Baxter)
Date: Sat, 25 Oct 2008 23:13:04 -0400
Subject: [time-nuts] How can it be :05 in one place and :30 in another
In-Reply-To: <20081025.204821.71120900.imp@bsdimp.com>
References: <4fdb424f0810251944t2a19ebaaw92bff5efc423bc03@mail.gmail.com>
	<20081025.204821.71120900.imp@bsdimp.com>
Message-ID: <4fdb424f0810252013l309068fcua957bdfc4dfe355e@mail.gmail.com>

I am confused.

Why do they do that?  what is the benefit?



On Sat, Oct 25, 2008 at 10:48 PM, Warner Losh <imp at bsdimp.com> wrote:

> From: "Gretchen Baxter" <gretchendenisebaxter at gmail.com>
> Subject: [time-nuts] How can it be :05 in one place and :30 in another
> Date: Sat, 25 Oct 2008 22:44:54 -0400
>
> > Hi,
> >
> > I went to http://www.timeanddate.com/worldclock/
> >
> > I saw that it was 10:35 in New York but in Adelaide it was 1:05 PM and in
> > New Delhi 8:05.
> >
> > How can that be?
>
> 1/2 hour offset timezones are more common than you think.
>
> Warner
>

From gretchendenisebaxter at gmail.com  Sun Oct 26 03:13:50 2008
From: gretchendenisebaxter at gmail.com (Gretchen Baxter)
Date: Sat, 25 Oct 2008 23:13:50 -0400
Subject: [time-nuts] How can it be :05 in one place and :30 in another
In-Reply-To: <20081026025106.DSUQ15831.nschwotgx01p.mx.bigpond.com@REX740>
References: <4fdb424f0810251944t2a19ebaaw92bff5efc423bc03@mail.gmail.com>
	<20081026025106.DSUQ15831.nschwotgx01p.mx.bigpond.com@REX740>
Message-ID: <4fdb424f0810252013k143b4316n3f6ae87856370056@mail.gmail.com>

So if a call is called for 10:00 in one part, it is really 10:30 in the
other?

that sounds lame.  is it?



On Sat, Oct 25, 2008 at 10:51 PM, Rex Moncur <rmoncur at bigpond.net.au> wrote:

> Gretchen
>
> Adelaide (South Australia) has a half hour time difference to Eastern
> Australian Time. These things are caused by having a Federation of States
> where the States make their own laws about time.
>
> Rex VK7MO
>
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
> Behalf Of Gretchen Baxter
> Sent: Sunday, 26 October 2008 1:45 PM
> To: Discussion of precise time and frequency measurement
> Subject: [time-nuts] How can it be :05 in one place and :30 in another
>
> Hi,
>
> I went to http://www.timeanddate.com/worldclock/
>
> I saw that it was 10:35 in New York but in Adelaide it was 1:05 PM and in
> New Delhi 8:05.
>
> How can that be?
>
> Gretchen
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

From hmurray at megapathdsl.net  Sun Oct 26 03:18:36 2008
From: hmurray at megapathdsl.net (Hal Murray)
Date: Sat, 25 Oct 2008 20:18:36 -0700
Subject: [time-nuts] How can it be :05 in one place and :30 in another
In-Reply-To: Message from "Gretchen Baxter" <gretchendenisebaxter@gmail.com> 
	of "Sat, 25 Oct 2008 22:44:54 EDT."
	<4fdb424f0810251944t2a19ebaaw92bff5efc423bc03@mail.gmail.com> 
Message-ID: <20081026031837.394A8BCD4@ip-64-139-1-69.sjc.megapath.net>


> I saw that it was 10:35 in New York but in Adelaide it was 1:05 PM and
> in New Delhi 8:05.

> How can that be?

There is a good map here:
  http://aa.usno.navy.mil/faq/docs/world_tzones.php
The ones with a * are off by 1/2 hour.  (google will find lots more)

It doesn't show Nepal which is 5:45 off from UTC.

How many other places are not whole hours or half hours?


-- 
These are my opinions, not necessarily my employer's.  I hate spam.





From matt at smiffytech.com  Sun Oct 26 03:20:59 2008
From: matt at smiffytech.com (Matthew Smith)
Date: Sun, 26 Oct 2008 13:50:59 +1030
Subject: [time-nuts] How can it be :05 in one place and :30 in another
In-Reply-To: <4fdb424f0810252013k143b4316n3f6ae87856370056@mail.gmail.com>
References: <4fdb424f0810251944t2a19ebaaw92bff5efc423bc03@mail.gmail.com>	<20081026025106.DSUQ15831.nschwotgx01p.mx.bigpond.com@REX740>
	<4fdb424f0810252013k143b4316n3f6ae87856370056@mail.gmail.com>
Message-ID: <4903E21B.4050107@smiffytech.com>

Quoth Gretchen Baxter at 2008-10-26 13:43...
> So if a call is called for 10:00 in one part, it is really 10:30 in the
> other?

You get used to it.  I'm in South Australia but most of my clients are 
in the Eastern States - it's no more confusing than when I was living in 
England and dealing with people in Western Europe.

I think that the whole point of timezones is to get noon roughly in the 
middle of the day; if there is only half an hours difference in sunrise 
between one place and the next, is it not logical to make the difference 
30 minutes?

Your original subject line had me confused - :05 in one place and :30 in 
another - that sounds more like a software error ;-)

But if you really want to get confused, consider not the zone offsets 
but the fact that there is no global standardisation on when daylight 
saving starts and ends - or whether it happens at all.  (Queensland does 
not have daylight saving.)  Our daylight saving started a fortnight 
early this year, most people not being aware of it until there was a 
reminder on the television news the night before.


-- 
Matthew Smith
Smiffytech - Technology Consulting & Web Application Development
Business: http://www.smiffytech.com/
Personal: http://www.smiffysplace.com/
LinkedIn: http://www.linkedin.com/in/smiffy


From N3IZN at aol.com  Sun Oct 26 03:21:59 2008
From: N3IZN at aol.com (N3IZN at aol.com)
Date: Sat, 25 Oct 2008 23:21:59 EDT
Subject: [time-nuts] How can it be :05 in one place and :30 in another
Message-ID: <cb9.3a4e5e6d.36353c57@aol.com>

ooh ooh ooh I know this one. That me doing my Arnold Horseshack imatation.

For cooridinationg contacts you use GMT or Zula time. So it doesn't matter 
what local time is.


**************
A Good Credit Score is 700 or Above. See yours 
in just 2 easy steps! 
(http://pr.atwola.com/promoclk/100000075x1211625659x1200715650/aol?redir=http://www.freecreditreport.com/pm/default.aspx?sc=668072&amp;
hmpgID=82&amp;bcd=emailfooter)

From mikes at flatsurface.com  Sun Oct 26 09:51:24 2008
From: mikes at flatsurface.com (Mike S)
Date: Sun, 26 Oct 2008 05:51:24 -0400
Subject: [time-nuts] How can it be :05 in one place and :30 in  another
In-Reply-To: <4fdb424f0810251944t2a19ebaaw92bff5efc423bc03@mail.gmail.co
 m>
References: <4fdb424f0810251944t2a19ebaaw92bff5efc423bc03@mail.gmail.com>
Message-ID: <20081026095126.327F61165C3@hamburg.alientech.net>

At 10:44 PM 10/25/2008, Gretchen Baxter wrote...
>I went to http://www.timeanddate.com/worldclock/
>
>I saw that it was 10:35 in New York but in Adelaide it was 1:05 PM and 
>in
>New Delhi 8:05.
>
>How can that be?

The world is round.



From magne at samfundet.no  Sun Oct 26 11:35:26 2008
From: magne at samfundet.no (=?ISO-8859-1?Q?Magne_M=E6hre?=)
Date: Sun, 26 Oct 2008 12:35:26 +0100
Subject: [time-nuts] How can it be :05 in one place and :30 in another
In-Reply-To: <4fdb424f0810251944t2a19ebaaw92bff5efc423bc03@mail.gmail.com>
References: <4fdb424f0810251944t2a19ebaaw92bff5efc423bc03@mail.gmail.com>
Message-ID: <490455FE.5090409@samfundet.no>

Gretchen Baxter wrote:
> Hi,
> 
> I went to http://www.timeanddate.com/worldclock/
> 
> I saw that it was 10:35 in New York but in Adelaide it was 1:05 PM and in
> New Delhi 8:05.
> 
> How can that be?

I take it the question really is why there are time zones which are not
an integral number of hours offset from UTC ? I guess there is mostly
two reasons for this, one of geography and one of politics.


Let's look at India:  The republic of India spans from
approx 68 deg. east to 89 deg. east, somewhat more than a full
time zone span. The start longitude for UTC+5 is at 60 east,
UTC+6 at 75 east  and UTC+7 at 90 east.   There are good reasons
for a country to have a single time zone (just think of trains, flights,
tv broadcasts etc., but there are a lot of other reasons), but for India
choosing an integral offset could be inconvenient as you want the
solar day to coincide with the clock day as much as possible..  So they
decided to go for  UTC+5:30 as a working compromise.

When you look at other examples, like Nepal and Venezuela, I think
you will find that political reasons have been more important.
Not going into details here, but I guess the honorable mr. Chavez
found it important to be on "venezuelan time" instead of the
atlantic standard time (or even worse, eastern time :)
I suspect some of the same goes for Nepal (at UTC+05:45)..
Indian standard time (UTC+05:30) would suit them just fine, but
somehow having your very own time can be, eh, positive for
national(istic) needs..

The other neighbour of Nepal, China, has taken another direction.
China, spanning 50 degrees of latitude (more than 3 complete time
zones), has chosen one common time zone.  Interestingly enough, this is
the Beijing time zone.  Beijing is located in the eastern part of
China, so the western regions of China observe noon at closer to 15:00
(that's 3pm for you USians).

--Magne


From stanw1le at verizon.net  Sun Oct 26 15:44:36 2008
From: stanw1le at verizon.net (Stan W1LE)
Date: Sun, 26 Oct 2008 11:44:36 -0400
Subject: [time-nuts] How can it be :05 in one place and :30 in another
In-Reply-To: <4fdb424f0810251944t2a19ebaaw92bff5efc423bc03@mail.gmail.com>
References: <4fdb424f0810251944t2a19ebaaw92bff5efc423bc03@mail.gmail.com>
Message-ID: <49049064.5010102@verizon.net>

Hello Gretchen,

The infamous 1/2 hour time zones.

Stan, W1LE


Gretchen Baxter wrote:
> Hi,
>
> I went to http://www.timeanddate.com/worldclock/
>
> I saw that it was 10:35 in New York but in Adelaide it was 1:05 PM and in
> New Delhi 8:05.
>
> How can that be?
>
> Gretchen
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>   



From magnus at rubidium.dyndns.org  Sun Oct 26 16:27:56 2008
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Sun, 26 Oct 2008 17:27:56 +0100
Subject: [time-nuts] How can it be :05 in one place and :30 in another
In-Reply-To: <4903E21B.4050107@smiffytech.com>
References: <4fdb424f0810251944t2a19ebaaw92bff5efc423bc03@mail.gmail.com>	<20081026025106.DSUQ15831.nschwotgx01p.mx.bigpond.com@REX740>	<4fdb424f0810252013k143b4316n3f6ae87856370056@mail.gmail.com>
	<4903E21B.4050107@smiffytech.com>
Message-ID: <49049A8C.10405@rubidium.dyndns.org>

Matthew,

> But if you really want to get confused, consider not the zone offsets 
> but the fact that there is no global standardisation on when daylight 
> saving starts and ends - or whether it happens at all.  (Queensland does 
> not have daylight saving.)  Our daylight saving started a fortnight 
> early this year, most people not being aware of it until there was a 
> reminder on the television news the night before.

The EC has a common daylight saving time. It is very convenient to have 
the same, especially when considering buissness and trade. There is a 
time offset, but it is stable even when switching between summer and 
winther time and back.

Cheers,
Magnus


From james.p.lux at jpl.nasa.gov  Sun Oct 26 16:33:20 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Sun, 26 Oct 2008 09:33:20 -0700
Subject: [time-nuts] How can it be :05 in one place and :30 in another
In-Reply-To: <4fdb424f0810252013l309068fcua957bdfc4dfe355e@mail.gmail.com>
Message-ID: <C529E9E0.20E4%James.P.Lux@jpl.nasa.gov>

Consider a country like India, which is a around 15 degrees of longitude
wide.  If you make the time zone on the half hour, then the entire country
can be on one time zone without sunrise/sunset times being too far out of
whack.

It IS nice to have noon occur roughly at solar noon.


On 10/25/08 8:13 PM, "Gretchen Baxter" <gretchendenisebaxter at gmail.com>
wrote:

> I am confused.
>
> Why do they do that?  what is the benefit?
>
>



From biwa at att.net  Sun Oct 26 16:45:37 2008
From: biwa at att.net (Burt I. Weiner)
Date: Sun, 26 Oct 2008 09:45:37 -0700
Subject: [time-nuts] Exceptions...
In-Reply-To: <mailman.1.1225022401.8873.time-nuts@febo.com>
References: <mailman.1.1225022401.8873.time-nuts@febo.com>
Message-ID: <7.0.0.16.2.20081026094403.037bd398@att.net>

Except for the flat or pointy places.

Burt, K6OQK

At 05:00 AM 10/26/2008, time-nuts-request at febo.com wrote
>At 10:44 PM 10/25/2008, Gretchen Baxter wrote...
> >I went to http://www.timeanddate.com/worldclock/
> >
> >I saw that it was 10:35 in New York but in Adelaide it was 1:05 PM and
> >in
> >New Delhi 8:05.
> >
> >How can that be?
>
>The world is round.

Burt I. Weiner Associates
Broadcast Technical Services
Glendale, California  U.S.A.
biwa at att.net
K6OQK 



From james.p.lux at jpl.nasa.gov  Sun Oct 26 17:01:01 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Sun, 26 Oct 2008 10:01:01 -0700
Subject: [time-nuts] Exceptions...
In-Reply-To: <7.0.0.16.2.20081026094403.037bd398@att.net>
Message-ID: <C529F05D.20EB%James.P.Lux@jpl.nasa.gov>




On 10/26/08 9:45 AM, "Burt I. Weiner" <biwa at att.net> wrote:

> Except for the flat or pointy places.
>
> Burt, K6OQK
>
> At 05:00 AM 10/26/2008, time-nuts-request at febo.com wrote
>> At 10:44 PM 10/25/2008, Gretchen Baxter wrote...
>>> I went to http://www.timeanddate.com/worldclock/
>>>
>>> I saw that it was 10:35 in New York but in Adelaide it was 1:05 PM and
>>> in
>>> New Delhi 8:05.
>>>
>>> How can that be?
>>
>> The world is round.
>
In the context of time-nuts, where we denigrate mere 1 ppm accuracy and talk
about parts in 1E12 and more.. The Earth, being ellipsoidal by about a part
in 300, is hardly "round".

Jim



From magnus at rubidium.dyndns.org  Sun Oct 26 17:24:42 2008
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Sun, 26 Oct 2008 18:24:42 +0100
Subject: [time-nuts] Exceptions...
In-Reply-To: <C529F05D.20EB%James.P.Lux@jpl.nasa.gov>
References: <C529F05D.20EB%James.P.Lux@jpl.nasa.gov>
Message-ID: <4904A7DA.4000809@rubidium.dyndns.org>

Lux, James P wrote:
> 
> 
> On 10/26/08 9:45 AM, "Burt I. Weiner" <biwa at att.net> wrote:
> 
>> Except for the flat or pointy places.
>>
>> Burt, K6OQK
>>
>> At 05:00 AM 10/26/2008, time-nuts-request at febo.com wrote
>>> At 10:44 PM 10/25/2008, Gretchen Baxter wrote...
>>>> I went to http://www.timeanddate.com/worldclock/
>>>>
>>>> I saw that it was 10:35 in New York but in Adelaide it was 1:05 PM and
>>>> in
>>>> New Delhi 8:05.
>>>>
>>>> How can that be?
>>> The world is round.
> In the context of time-nuts, where we denigrate mere 1 ppm accuracy and talk
> about parts in 1E12 and more.. The Earth, being ellipsoidal by about a part
> in 300, is hardly "round".

OK... it's a fairly ellipsoid object... and not flat.

Cheers,
Magnus


From jltran at worldnet.att.net  Sun Oct 26 17:44:32 2008
From: jltran at worldnet.att.net (J. L. Trantham)
Date: Sun, 26 Oct 2008 12:44:32 -0500
Subject: [time-nuts] ?Death of TBolt?
Message-ID: <5DA4B63854064ACC886D782D00F0D26A@S0028384766>

I have developed a problem with one of the TBolt's that I got through TAPR.

I was using it with the supplied power supply to provide a 1 PPS to a Brooks
Shera controller to discipline an HP105B 5 MHz oscillator.  I also have a
Z3816A that I was using to clock a 5370B and a 5372A and to compare the 10
MHz out of the TBolt and the HP105B.  It had been on for about 3 weeks and
all was well, talking to TBoltMon, 'locked' lissagous figure on a Tek 485
scope, frequencies of 10.000 000 000 00 and 5.000 000 000 00 MHz,
respectively, +/- about 50E-11, etc.

I turned all equipment off last night, getting ready for the next step of
installation of the equipment in racks.

This AM, I turned the TBolt back on and no communication with TBoltMon.  It
did have a sine wave out around 10 MHz.  I did not check the 1 PPS.  I
switched power supplies and same response.  I turned on the 3816A and
allowed it to get to a FFOM of 0 and watched the 10 MHz signals on the
scope.  The TBolt 10 MHz is way off, but after a while, it does eventually
come close to the 3816A but never 'locks'.  It also seems to heat up
appropriately further indicating that the oven is heating.  My other TAPR
TBolt fired right up, no problem, and 'locked', with the lissagous figure
'frozen'.  I also tried the 'suspect' power supply (after verifying
voltages) on the 'good' TBolt and all was well.

Any ideas?  An on board power issue failing the receiver and the RS232?  The
power supply not a good choice for long term use?  Any circuit diagram
available?

I opened the TBolt and no obvious issues.

All suggestions welcome.  

Thanks,

Joe



From namichie at gmail.com  Sun Oct 26 22:43:54 2008
From: namichie at gmail.com (Neville Michie)
Date: Mon, 27 Oct 2008 09:43:54 +1100
Subject: [time-nuts] ?Death of TBolt?
In-Reply-To: <5DA4B63854064ACC886D782D00F0D26A@S0028384766>
References: <5DA4B63854064ACC886D782D00F0D26A@S0028384766>
Message-ID: <246F55A2-9B8F-42A9-A4BD-B798FBF509F5@gmail.com>

HI,
I had a TBOLT that developed communication problems and I assumed the  
TBOLT
was at fault. Nothing seemed to make it give out PPS or 10MHz.
It turned out that my PC running VISTA had messed with the com port  
allocations on
the serial to USB converter and although I thought that I had tried  
everything I must
have missed the vital combination of checks and settings.
Ultimately I fired up an old PC running windoze 2000 with a serial  
port as I
suspected the USB-serial converters of not working and I
managed to get a replacement TBOLT to run. When I plugged the 1st TBOLT
into the same set up it ran TBOLTMON OK and has never looked back.
Once I knew the problem was in the COM port emulation I soon got it  
right
and finally got the laptop to run TBOLTMON through USB-serial  
converters.
There seem to be several levels of settings needed in VISTA to get a  
COM port
to work through the USB-serial converter.

I tried two different brands of USB-serial converters on my laptop  
and both work perfectly well.
I hope this may help you,
Neville Michie






On 27/10/2008, at 4:44 AM, J. L. Trantham wrote:

> I have developed a problem with one of the TBolt's that I got  
> through TAPR.
>
> I was using it with the supplied power supply to provide a 1 PPS to  
> a Brooks
> Shera controller to discipline an HP105B 5 MHz oscillator.  I also  
> have a
> Z3816A that I was using to clock a 5370B and a 5372A and to compare  
> the 10
> MHz out of the TBolt and the HP105B.  It had been on for about 3  
> weeks and
> all was well, talking to TBoltMon, 'locked' lissagous figure on a  
> Tek 485
> scope, frequencies of 10.000 000 000 00 and 5.000 000 000 00 MHz,
> respectively, +/- about 50E-11, etc.
>
> I turned all equipment off last night, getting ready for the next  
> step of
> installation of the equipment in racks.
>
> This AM, I turned the TBolt back on and no communication with  
> TBoltMon.  It
> did have a sine wave out around 10 MHz.  I did not check the 1 PPS.  I
> switched power supplies and same response.  I turned on the 3816A and
> allowed it to get to a FFOM of 0 and watched the 10 MHz signals on the
> scope.  The TBolt 10 MHz is way off, but after a while, it does  
> eventually
> come close to the 3816A but never 'locks'.  It also seems to heat up
> appropriately further indicating that the oven is heating.  My  
> other TAPR
> TBolt fired right up, no problem, and 'locked', with the lissagous  
> figure
> 'frozen'.  I also tried the 'suspect' power supply (after verifying
> voltages) on the 'good' TBolt and all was well.
>
> Any ideas?  An on board power issue failing the receiver and the  
> RS232?  The
> power supply not a good choice for long term use?  Any circuit diagram
> available?
>
> I opened the TBolt and no obvious issues.
>
> All suggestions welcome.
>
> Thanks,
>
> Joe
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ 
> time-nuts
> and follow the instructions there.



From jim77742 at gmail.com  Mon Oct 27 00:34:53 2008
From: jim77742 at gmail.com (Jim Palfreyman)
Date: Mon, 27 Oct 2008 11:34:53 +1100
Subject: [time-nuts] Exceptions...
In-Reply-To: <4904A7DA.4000809@rubidium.dyndns.org>
References: <C529F05D.20EB%James.P.Lux@jpl.nasa.gov>
	<4904A7DA.4000809@rubidium.dyndns.org>
Message-ID: <f616e0f80810261734r3b994e0do66cbe3edc4845170@mail.gmail.com>

If the Earth were a snooker ball you would not be able to tell it is not a
sphere...

2008/10/27 Magnus Danielson <magnus at rubidium.dyndns.org>

> Lux, James P wrote:
> >
> >
> > On 10/26/08 9:45 AM, "Burt I. Weiner" <biwa at att.net> wrote:
> >
> >> Except for the flat or pointy places.
> >>
> >> Burt, K6OQK
> >>
> >> At 05:00 AM 10/26/2008, time-nuts-request at febo.com wrote
> >>> At 10:44 PM 10/25/2008, Gretchen Baxter wrote...
> >>>> I went to http://www.timeanddate.com/worldclock/
> >>>>
> >>>> I saw that it was 10:35 in New York but in Adelaide it was 1:05 PM and
> >>>> in
> >>>> New Delhi 8:05.
> >>>>
> >>>> How can that be?
> >>> The world is round.
> > In the context of time-nuts, where we denigrate mere 1 ppm accuracy and
> talk
> > about parts in 1E12 and more.. The Earth, being ellipsoidal by about a
> part
> > in 300, is hardly "round".
>
> OK... it's a fairly ellipsoid object... and not flat.
>
> Cheers,
> Magnus
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

From mikes at flatsurface.com  Mon Oct 27 10:37:45 2008
From: mikes at flatsurface.com (Mike S)
Date: Mon, 27 Oct 2008 06:37:45 -0400
Subject: [time-nuts] Exceptions...
In-Reply-To: <C529F05D.20EB%James.P.Lux@jpl.nasa.gov>
References: <7.0.0.16.2.20081026094403.037bd398@att.net>
	<C529F05D.20EB%James.P.Lux@jpl.nasa.gov>
Message-ID: <20081027103809.8D62D1165C3@hamburg.alientech.net>

At 01:01 PM 10/26/2008, Lux, James P wrote...
> >> The world is round.
> >
>In the context of time-nuts, where we denigrate mere 1 ppm accuracy 
>and talk
>about parts in 1E12 and more.. The Earth, being ellipsoidal by about a 
>part
>in 300, is hardly "round".

And this affects local solar time exactly - how? 



From magnus at rubidium.dyndns.org  Mon Oct 27 09:06:01 2008
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Mon, 27 Oct 2008 10:06:01 +0100
Subject: [time-nuts] Exceptions...
In-Reply-To: <20081026.203611.1102527811.imp@bsdimp.com>
References: <C529F05D.20EB%James.P.Lux@jpl.nasa.gov>	<4904A7DA.4000809@rubidium.dyndns.org>
	<20081026.203611.1102527811.imp@bsdimp.com>
Message-ID: <49058479.7030300@rubidium.dyndns.org>

M. Warner Losh wrote:
> In message: <4904A7DA.4000809 at rubidium.dyndns.org>
>             Magnus Danielson <magnus at rubidium.dyndns.org> writes:
> : Lux, James P wrote:
> : > 
> : > 
> : > On 10/26/08 9:45 AM, "Burt I. Weiner" <biwa at att.net> wrote:
> : > 
> : >> Except for the flat or pointy places.
> : >>
> : >> Burt, K6OQK
> : >>
> : >> At 05:00 AM 10/26/2008, time-nuts-request at febo.com wrote
> : >>> At 10:44 PM 10/25/2008, Gretchen Baxter wrote...
> : >>>> I went to http://www.timeanddate.com/worldclock/
> : >>>>
> : >>>> I saw that it was 10:35 in New York but in Adelaide it was 1:05 PM and
> : >>>> in
> : >>>> New Delhi 8:05.
> : >>>>
> : >>>> How can that be?
> : >>> The world is round.
> : > In the context of time-nuts, where we denigrate mere 1 ppm accuracy and talk
> : > about parts in 1E12 and more.. The Earth, being ellipsoidal by about a part
> : > in 300, is hardly "round".
> : 
> : OK... it's a fairly ellipsoid object... and not flat.
> 
> And the 1/2 time zones have nothing to do with the shape of the earth
> in fine detail, but rather the fact that it is somewhat ball-like in a
> gross, part in 10 sort of way :-)[*]

The hint is rather that since it i roundish, turns around its axis 
timezones as such is needed. Contrary to popular beleif, people do want 
their time to predict the rising, noon and setting of the sun. Thus, all 
countries running UTC would not be a solution. The Indian solution to 
solve for conflicting requirements is certainly a reasnoble solution.

However, there are valid reasons to use UTC throughout the world for 
certain tasks, but those does not necessarilly include civil timekeeping.

Cheers,
Magnus


From jltran at worldnet.att.net  Mon Oct 27 02:07:41 2008
From: jltran at worldnet.att.net (J. L. Trantham)
Date: Sun, 26 Oct 2008 21:07:41 -0500
Subject: [time-nuts] ?Death of TBolt?
In-Reply-To: <246F55A2-9B8F-42A9-A4BD-B798FBF509F5@gmail.com>
Message-ID: <CB3665F8B07042C997E14936FB422E04@S0028384766>

Neville,

Thanks for the reply.  I forgot to give the details of the computer.

I am using an old Dell running Win2000 Pro that has two serial ports and
allows me to monitor the 3816A and the TBolt at the same time.  As I said,
the other TBolt works fine when connected the same way.

I still think the problem is in the TBolt but I am not sure why it is there.
I wonder about the power supply somehow going over voltage or something.

Joe

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Neville Michie
Sent: Sunday, October 26, 2008 5:44 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] ?Death of TBolt?

HI,
I had a TBOLT that developed communication problems and I assumed the  
TBOLT
was at fault. Nothing seemed to make it give out PPS or 10MHz.
It turned out that my PC running VISTA had messed with the com port  
allocations on
the serial to USB converter and although I thought that I had tried  
everything I must
have missed the vital combination of checks and settings.
Ultimately I fired up an old PC running windoze 2000 with a serial  
port as I
suspected the USB-serial converters of not working and I
managed to get a replacement TBOLT to run. When I plugged the 1st TBOLT
into the same set up it ran TBOLTMON OK and has never looked back.
Once I knew the problem was in the COM port emulation I soon got it  
right
and finally got the laptop to run TBOLTMON through USB-serial  
converters.
There seem to be several levels of settings needed in VISTA to get a  
COM port
to work through the USB-serial converter.

I tried two different brands of USB-serial converters on my laptop  
and both work perfectly well.
I hope this may help you,
Neville Michie






On 27/10/2008, at 4:44 AM, J. L. Trantham wrote:

> I have developed a problem with one of the TBolt's that I got  
> through TAPR.
>
> I was using it with the supplied power supply to provide a 1 PPS to  
> a Brooks
> Shera controller to discipline an HP105B 5 MHz oscillator.  I also  
> have a
> Z3816A that I was using to clock a 5370B and a 5372A and to compare  
> the 10
> MHz out of the TBolt and the HP105B.  It had been on for about 3  
> weeks and
> all was well, talking to TBoltMon, 'locked' lissagous figure on a  
> Tek 485
> scope, frequencies of 10.000 000 000 00 and 5.000 000 000 00 MHz,
> respectively, +/- about 50E-11, etc.
>
> I turned all equipment off last night, getting ready for the next  
> step of
> installation of the equipment in racks.
>
> This AM, I turned the TBolt back on and no communication with  
> TBoltMon.  It
> did have a sine wave out around 10 MHz.  I did not check the 1 PPS.  I
> switched power supplies and same response.  I turned on the 3816A and
> allowed it to get to a FFOM of 0 and watched the 10 MHz signals on the
> scope.  The TBolt 10 MHz is way off, but after a while, it does  
> eventually
> come close to the 3816A but never 'locks'.  It also seems to heat up
> appropriately further indicating that the oven is heating.  My  
> other TAPR
> TBolt fired right up, no problem, and 'locked', with the lissagous  
> figure
> 'frozen'.  I also tried the 'suspect' power supply (after verifying
> voltages) on the 'good' TBolt and all was well.
>
> Any ideas?  An on board power issue failing the receiver and the  
> RS232?  The
> power supply not a good choice for long term use?  Any circuit diagram
> available?
>
> I opened the TBolt and no obvious issues.
>
> All suggestions welcome.
>
> Thanks,
>
> Joe
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ 
> time-nuts
> and follow the instructions there.


_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



From james.p.lux at jpl.nasa.gov  Mon Oct 27 04:05:03 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Sun, 26 Oct 2008 21:05:03 -0700
Subject: [time-nuts] Exceptions...
In-Reply-To: <f616e0f80810261734r3b994e0do66cbe3edc4845170@mail.gmail.com>
Message-ID: <C52A8BFF.2100%James.P.Lux@jpl.nasa.gov>




On 10/26/08 5:34 PM, "Jim Palfreyman" <jim77742 at gmail.com> wrote:

> If the Earth were a snooker ball you would not be able to tell it is not a
> sphere...
>
Perhaps after consuming an ale or two..

Let's see.. It's out of round by 1 part in 300.  Human visual acuity is
about 1 minute of arc, 1/60th of a degree, or about 0.3 milliradian. Holding
that snooker ball at arms length (call it a meter), and it's roughly 52 mm
in diameter (per Wikipedia), so it subtends 52 mrad, and the 1/300 out of
round would be 1/6 mrad.  Oooh.. Pretty close to human visual resolution.

Hold that ball a bit closer (which, if you suspected it was not spherical,
you might be tempted to do..), and you had a real circle to compare to?
Would it look visibily non spherical? Probably depends on how much
astigmatism you have.
Certainly, one could easily measure the difference (160 micron)

Here's a real question, though.  Would a ball that's out of round by one
part in 300 not roll straight?


While we're speaking of polishing cannon balls...
Could this valuable piece of information be used to win a bar bet?  I'm
going to a conference soon, and such things are useful to know during poster
sessions/receptions.

Jim



From imp at bsdimp.com  Mon Oct 27 02:36:11 2008
From: imp at bsdimp.com (M. Warner Losh)
Date: Sun, 26 Oct 2008 20:36:11 -0600 (MDT)
Subject: [time-nuts] Exceptions...
In-Reply-To: <4904A7DA.4000809@rubidium.dyndns.org>
References: <C529F05D.20EB%James.P.Lux@jpl.nasa.gov>
	<4904A7DA.4000809@rubidium.dyndns.org>
Message-ID: <20081026.203611.1102527811.imp@bsdimp.com>

In message: <4904A7DA.4000809 at rubidium.dyndns.org>
            Magnus Danielson <magnus at rubidium.dyndns.org> writes:
: Lux, James P wrote:
: > 
: > 
: > On 10/26/08 9:45 AM, "Burt I. Weiner" <biwa at att.net> wrote:
: > 
: >> Except for the flat or pointy places.
: >>
: >> Burt, K6OQK
: >>
: >> At 05:00 AM 10/26/2008, time-nuts-request at febo.com wrote
: >>> At 10:44 PM 10/25/2008, Gretchen Baxter wrote...
: >>>> I went to http://www.timeanddate.com/worldclock/
: >>>>
: >>>> I saw that it was 10:35 in New York but in Adelaide it was 1:05 PM and
: >>>> in
: >>>> New Delhi 8:05.
: >>>>
: >>>> How can that be?
: >>> The world is round.
: > In the context of time-nuts, where we denigrate mere 1 ppm accuracy and talk
: > about parts in 1E12 and more.. The Earth, being ellipsoidal by about a part
: > in 300, is hardly "round".
: 
: OK... it's a fairly ellipsoid object... and not flat.

And the 1/2 time zones have nothing to do with the shape of the earth
in fine detail, but rather the fact that it is somewhat ball-like in a
gross, part in 10 sort of way :-)[*]

Warner


From imp at bsdimp.com  Mon Oct 27 02:28:34 2008
From: imp at bsdimp.com (M. Warner Losh)
Date: Sun, 26 Oct 2008 20:28:34 -0600 (MDT)
Subject: [time-nuts] How can it be :05 in one place and :30 in another
In-Reply-To: <4fdb424f0810252013l309068fcua957bdfc4dfe355e@mail.gmail.com>
References: <4fdb424f0810251944t2a19ebaaw92bff5efc423bc03@mail.gmail.com>
	<20081025.204821.71120900.imp@bsdimp.com>
	<4fdb424f0810252013l309068fcua957bdfc4dfe355e@mail.gmail.com>
Message-ID: <20081026.202834.-957833205.imp@bsdimp.com>

In message: <4fdb424f0810252013l309068fcua957bdfc4dfe355e at mail.gmail.com>
            "Gretchen Baxter" <gretchendenisebaxter at gmail.com> writes:
: I am confused.
: 
: Why do they do that?  what is the benefit?

Better correspondence of local time to solar time when the population
centers of the time zones are located near the boundary of a time
zone...

Warner


From james.p.lux at jpl.nasa.gov  Mon Oct 27 14:08:38 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Mon, 27 Oct 2008 07:08:38 -0700
Subject: [time-nuts] Exceptions...
In-Reply-To: <20081027103809.8D62D1165C3@hamburg.alientech.net>
Message-ID: <C52B1976.2119%James.P.Lux@jpl.nasa.gov>




On 10/27/08 3:37 AM, "Mike S" <mikes at flatsurface.com> wrote:

> At 01:01 PM 10/26/2008, Lux, James P wrote...
>>>> The world is round.
>>>
>> In the context of time-nuts, where we denigrate mere 1 ppm accuracy
>> and talk
>> about parts in 1E12 and more.. The Earth, being ellipsoidal by about a
>> part
>> in 300, is hardly "round".
>
> And this affects local solar time exactly - how?
>

My original comment was more along the lines of a humorous comment about the
use of the word "round" on a list where we deal in parts in 1E12..

BUT, since you ask.
The ellipsoidal nature raises all sorts of interesting questions when
calculating the apparent direction of the sun.  Certainly, it will change
sunset and sunrise times, relative to a spherical earth. Noon is noon, so
the azimuth is always 180 or 0, but the elevation will change.  However,
since in a time zone, there's only a single line where noon corresponds to
local solar noon, I suspect there is some small difference in timing between
the times when the sun appears highest in the sky for sphere and ellipsoid.

It's left as an exercise for the reader to determine whether the difference
in time is big enough to measure.  (angular measurements of the sun's
position are readily possible to fractions of a minute of arc, with a
telescopic sight.. And it moves, to a zeroth order, about a degree in 4
minutes)

For what it's worth, the solar noon/local noon varies +/- 15 minutes during
the year anyway, but that's more due to the non-roundness of the Earth's
orbit around the sun. (in the parts per hundred area.. It varies over time)

In fact, there's an interesting paper from IoN (Shaw, 2002) describing
determining one's position using an analemma and a clock, so I would assume
that if one knows the position, you could determine the time.



From swithrow at idcomm.com  Mon Oct 27 21:59:19 2008
From: swithrow at idcomm.com (Skip Withrow)
Date: Mon, 27 Oct 2008 15:59:19 -0600
Subject: [time-nuts] Anyone have McCoy OSC92-100B data?
Message-ID: <20081027215919.97B961714862@mailhost.idcomm.com>


I have acquired a nice 10 MHz oscillator, but have absolutely no data.  
Model is marked as a McCoy OSC92-100B, it is rectangular 3"x2"x1.5" with six 
leads out one side.  Does anyone have the pinout, operating voltage, EFC 
voltage for this unit?  Thanks in advance, as always. 

Regards,
Skip Withrow


From phk at phk.freebsd.dk  Mon Oct 27 22:54:06 2008
From: phk at phk.freebsd.dk (Poul-Henning Kamp)
Date: Mon, 27 Oct 2008 22:54:06 +0000
Subject: [time-nuts] DIY Loran-C frequency receiver: it lives!
In-Reply-To: Your message of "Sun, 28 Sep 2008 21:46:12 GMT."
	<12050.1222638372@critter.freebsd.dk> 
Message-ID: <51888.1225148046@critter.freebsd.dk>


I have managed to nail a signal with my new DIY loran-C reciver:

	http://phk.freebsd.dk/misc/Loran2/proof.png

Trace 4 (cyan) is the raw antenna signal

Trace 3 (red) is the integrated (averaged) signal, as output by the
receiver using the D/A converter.

The receiver consists of only four hardware parts:

	A Olimex ADuc-P7026 prototyping board.
	A TAPR clockblock
	My funky old $20 loop antenna: http://phk.freebsd.dk/loran-c/Antenna/
	A small E1/T1 telco trafo for balancing the signal.

Everything else is software.

Obligatory picture of messy workbench:

	http://phk.freebsd.dk/misc/Loran2/dsc_3327.jpg

Right now the software just integrates the first 900?s of the GRI,
one has to place the GRI manually over the signal, but getting
the my prototype software moved over so it can do that automatically
is next.

Poul-Henning

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.


From richiem at hughes.net  Mon Oct 27 23:26:57 2008
From: richiem at hughes.net (Richard Moore)
Date: Mon, 27 Oct 2008 16:26:57 -0700
Subject: [time-nuts] McCoy OCXO pin outs
In-Reply-To: <mailman.10.1225144771.2439.time-nuts@febo.com>
References: <mailman.10.1225144771.2439.time-nuts@febo.com>
Message-ID: <39A659E0-9622-45B6-A17D-8461B447EB51@hughes.net>


On Oct 27, 2008, at 2:59 PM, time-nuts-request at febo.com wrote:

> I have acquired a nice 10 MHz oscillator, but have absolutely no data.
> Model is marked as a McCoy OSC92-100B, it is rectangular 3"x2"x1.5"  
> with six
> leads out one side.  Does anyone have the pinout, operating  
> voltage, EFC
> voltage for this unit?  Thanks in advance, as always.
>
> Regards,
> Skip Withrow

Google isotemp 134 and the first listing will likely be a pdf link  
for the specs and pin-outs.

Best,
Dick Moore


From rogburn at warpspeed1.net  Mon Oct 27 23:33:43 2008
From: rogburn at warpspeed1.net (Robert Ogburn)
Date: Mon, 27 Oct 2008 18:33:43 -0500
Subject: [time-nuts] Anyone have McCoy OSC92-100B data?
In-Reply-To: <20081027215919.97B961714862@mailhost.idcomm.com>
References: <20081027215919.97B961714862@mailhost.idcomm.com>
Message-ID: <49064FD7.4060403@warpspeed1.net>

Skip Withrow wrote:
> I have acquired a nice 10 MHz oscillator, but have absolutely no data.  
> Model is marked as a McCoy OSC92-100B, it is rectangular 3"x2"x1.5" with six 
> leads out one side.  Does anyone have the pinout, operating voltage, EFC 
> voltage for this unit?  Thanks in advance, as always. 
>
> Regards,
> Skip Withrow
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>
>   
Skip,

I believe that the McCoy OSC92-100B was also manufactured in the Isotemp 
OCXO 134 series.  I have some of the McCoy units operating as if they 
were the Isotemps... (some restrictions apply)   See 
http://www.isotemp.com/docs/OCXO134-10Spec.pdf
for the info.

Keep us posted.

Bob
HBR/AF
Manvel, Texas



From normn3ykf at stny.rr.com  Tue Oct 28 00:14:03 2008
From: normn3ykf at stny.rr.com (Norman J McSweyn)
Date: Mon, 27 Oct 2008 20:14:03 -0400
Subject: [time-nuts] labview, gpib, gps , logging data and lost data points!!
Message-ID: <4906594B.7060601@stny.rr.com>

Hi!
I'm logging data from an HP 5335a (using it as a time interval counter). 
and from a Motorola gps board ( text data).
The test setup is comparing the 1pps output from the gps board to a 
divided (Thank you Dave Partridge!!!!!!) down 10 MHz from a Trimble 
Thunderbolt. The text data is used to post process the measurement from 
the 5335a reflecting the 1pps error (+/- 15E-9). The ver is LV 8

Code description:
Each instrument has it's own VI and I run them simultaneously, 
collecting data and storing it in text files. The individual vi's are 
for loops with the iterations being the number of seconds that I want to 
log. Inside the loop is obviously a delay. The data is time stamped with 
seconds enabled.

The problem is that somewhere in the 40k data points some (not all at 
the same time or sometimes one here and there or sometimes a bunch at 
once) aren't' collected.

Solutions that I've tried:
Using the 1pps to drive the parallel port so that I've got a hardware 
time hack. When I had both vi's in the same for loop things didn't go 
well. Not really sure what happened. Separated them. Works well now 
(except for the four or five lost data points in 40k)

Varying the time constant. It's helped lots, but I really don't' want to 
lose any data.

Have tried timed loops. Works fine with one process. Try to do two (gpib 
and serial for the gps) and it hangs the PC.

Solution that I think would work:
A way of firmly triggering a start event with labview. I've got a time 
server so windoze time (or lack of it!) is not an issue. (This may be an 
issue. Played around with it. Turning off polling made a difference.)

I'm not really a programmer. Actually play with trains for a living. 
Will be on vacation for the next week. Not much to do so I'll be able to 
play lots.
Thoughts, questions, comments and humor greatly appreciated.
Thanks for your time,
Norm n3ykf


From atomicelmer at gmail.com  Tue Oct 28 00:28:49 2008
From: atomicelmer at gmail.com (Greg Anderson)
Date: Mon, 27 Oct 2008 18:28:49 -0600
Subject: [time-nuts] My new Podcast about "Atomic Timekeeping"
Message-ID: <466cf4790810271728s5127fecg7636df7e5edd32f0@mail.gmail.com>

Since the birthday when I was given my first digital watch, I've been
concerned about having my watches and clocks set to "the correct
time," right down to the second. In the 1980s I was able to determine
the time using WWV on a shortwave radio. Later, I was thrilled to see
radio controlled clocks which would set themselves using WWVB as a
reference. Since 1995 I've purchased hundreds of radio controlled
clocks for my own collection and to give away to loved ones whenever
there's a special occasion.

For about ten years I've run a little web page to help spread the word
about radio controlled clocks. But I must say that I had no idea
anyone could privately own a real atomic clock. I always though the
real things were reserved for big-time science organizations and/or
government-run facilities. You guys are really something!

My latest project is an audio podcast about the wonders of "atomic
timekeeping," although I admit my emphasis will probably remain with
inexpensive, radio controlled clocks made for "average consumers."

I just started this and, so far, I've only released four episodes. I
haven't done much publicity and I'd love it if I got a whole lot more
listeners. So you're all invited. Again, my podcasts may not be nearly
advanced enough to interest the folks on this mailing list but maybe
you have friends, children or grandchildren who'd enjoy a discussion
about this stuff at what I consider a "Jr. High School Science" level.

Please feel free to check out the official show notes blog...

http://atomicelmer.blogspot.com

..or the feed version of that same blog...

http://feeds.feedburner.com/blogspot/atomicelmer
(The feed version allows stuff like an iTunes subscription, etc.)

I will be releasing the new, fifth episode this Thursday afternoon at
5:00 PM Eastern Time. It's my "Daylight Saving Time Special."


From had at to-way.com  Tue Oct 28 00:52:00 2008
From: had at to-way.com (Had)
Date: Mon, 27 Oct 2008 17:52:00 -0700
Subject: [time-nuts] My new Podcast about "Atomic Timekeeping"
In-Reply-To: <466cf4790810271728s5127fecg7636df7e5edd32f0@mail.gmail.com
 >
References: <466cf4790810271728s5127fecg7636df7e5edd32f0@mail.gmail.com>
Message-ID: <20081028005200.E4A2B192826@mail-in04.adhost.com>


Welcome Greg,

Everybody has to jump in someplace. Some of us just jump in a little deeper.

Had
K7MLR


At 05:28 PM 10/27/2008, you wrote:
>Since the birthday when I was given my first digital watch, I've been
>concerned about having my watches and clocks set to "the correct
>time," right down to the second. In the 1980s I was able to determine
>the time using WWV on a shortwave radio. Later, I was thrilled to see
>radio controlled clocks which would set themselves using WWVB as a
>reference. Since 1995 I've purchased hundreds of radio controlled
>clocks for my own collection and to give away to loved ones whenever
>there's a special occasion.
>
>For about ten years I've run a little web page to help spread the word
>about radio controlled clocks. But I must say that I had no idea
>anyone could privately own a real atomic clock. I always though the
>real things were reserved for big-time science organizations and/or
>government-run facilities. You guys are really something!
>
>My latest project is an audio podcast about the wonders of "atomic
>timekeeping," although I admit my emphasis will probably remain with
>inexpensive, radio controlled clocks made for "average consumers."
>
>I just started this and, so far, I've only released four episodes. I
>haven't done much publicity and I'd love it if I got a whole lot more
>listeners. So you're all invited. Again, my podcasts may not be nearly
>advanced enough to interest the folks on this mailing list but maybe
>you have friends, children or grandchildren who'd enjoy a discussion
>about this stuff at what I consider a "Jr. High School Science" level.
>
>Please feel free to check out the official show notes blog...
>
>http://atomicelmer.blogspot.com
>
>..or the feed version of that same blog...
>
>http://feeds.feedburner.com/blogspot/atomicelmer
>(The feed version allows stuff like an iTunes subscription, etc.)
>
>I will be releasing the new, fifth episode this Thursday afternoon at
>5:00 PM Eastern Time. It's my "Daylight Saving Time Special."
>
>_______________________________________________
>time-nuts mailing list -- time-nuts at febo.com
>To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>and follow the instructions there.




From jra at febo.com  Tue Oct 28 13:07:31 2008
From: jra at febo.com (John Ackermann N8UR)
Date: Tue, 28 Oct 2008 09:07:31 -0400
Subject: [time-nuts] Administrivia -- time-nuts mailing list web access
	problems
Message-ID: <49070E93.8060109@febo.com>

I don't know (yet) what happened, but something broke in the last couple 
of days and all the web interfaces (e.g., for subscribing, or reading 
the archives) to the mailman mailing list system at febo.com are 
currently broken.

The good news is that the problem is so pervasive, it must have a simple 
cause :-).

I hope to get it fixed Real Soon Now, and will post a note here when 
that happens.  Sorry for any inconvenience.

John


From jra at febo.com  Tue Oct 28 16:59:26 2008
From: jra at febo.com (John Ackermann N8UR)
Date: Tue, 28 Oct 2008 12:59:26 -0400
Subject: [time-nuts] time-nuts web interface fixed (I hope)
Message-ID: <490744EE.8040908@febo.com>

I think I found the bug; somehow the web server and mailman processes 
weren't able to write in each other's files, which caused various forms 
of barfage.  Don't know why it suddenly broke, though...

Sorry for the inconvenience.

John


From magnus at rubidium.dyndns.org  Tue Oct 28 17:19:10 2008
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Tue, 28 Oct 2008 18:19:10 +0100
Subject: [time-nuts] time-nuts web interface fixed (I hope)
In-Reply-To: <490744EE.8040908@febo.com>
References: <490744EE.8040908@febo.com>
Message-ID: <4907498E.5080209@rubidium.dyndns.org>

John Ackermann N8UR wrote:
> I think I found the bug; somehow the web server and mailman processes 
> weren't able to write in each other's files, which caused various forms 
> of barfage.  Don't know why it suddenly broke, though...
> 
> Sorry for the inconvenience.

If it helps... no it doesn't, but anyway... I have suffered the same 
problem.

Runs two apache/mailman/postfix setups. They are usually wellbehaved.

Cheers,
Magnus


From df6jb at ulrich-bangert.de  Tue Oct 28 18:52:36 2008
From: df6jb at ulrich-bangert.de (Ulrich Bangert)
Date: Tue, 28 Oct 2008 19:52:36 +0100
Subject: [time-nuts] Disregard, test message only
Message-ID: <B86287752A89408882730FEBD4C6586E@athlon>



Ulrich Bangert
www.ulrich-bangert.de
Ortholzer Weg 1
27243 Gross Ippener 



From stanley_reynolds at yahoo.com  Tue Oct 28 22:48:06 2008
From: stanley_reynolds at yahoo.com (Stanley Reynolds)
Date: Tue, 28 Oct 2008 15:48:06 -0700 (PDT)
Subject: [time-nuts] firmware bug ???
Message-ID: <100472.45697.qm@web30305.mail.mud.yahoo.com>

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=250304924135
?
?
My new to me Trak Systems 8820 GPS Station displays the wrong number of days it counts 73 when it should be 302. Hours, minutes, and seconds are correct. Re-seating chips and adjusting 10 MHz oscillator has the tracking and locked LEDs on. Waiting on a new LCD display to arrive to fix that part.
?
It has a magnavox "GPS Engine copy right 1991" OEM module which may be the problem.
?
Does anyone have info on this unit or the magnavox GPS engine ?

From ka2cdk at cox.net  Tue Oct 28 23:17:48 2008
From: ka2cdk at cox.net (Thomas A. Frank)
Date: Tue, 28 Oct 2008 19:17:48 -0400
Subject: [time-nuts] My new Podcast about "Atomic Timekeeping"
In-Reply-To: <20081028005200.E4A2B192826@mail-in04.adhost.com>
References: <466cf4790810271728s5127fecg7636df7e5edd32f0@mail.gmail.com>
	<20081028005200.E4A2B192826@mail-in04.adhost.com>
Message-ID: <CD3B4101-14BB-4C09-AD34-FBC98C0BE7B5@cox.net>

 >Welcome Greg;
 >Everybody has to jump in someplace. Some of us just jump in a  
little deeper.


A few drown...

(nice podcast, by the way)

Tom Frank, KA2CDK




From stanley_reynolds at yahoo.com  Tue Oct 28 23:22:15 2008
From: stanley_reynolds at yahoo.com (Stanley Reynolds)
Date: Tue, 28 Oct 2008 16:22:15 -0700 (PDT)
Subject: [time-nuts] firmware bug ???
Message-ID: <238339.29574.qm@web30304.mail.mud.yahoo.com>

Follow up I checked the?IRIG-B Out and it has the same 73 days, if I can interface a new GPS module wonder if that would fix the?"GPS Week Number Rollover (WNRO)" http://leapsecond.com/notes/gpswnro.htm?that I think I have ?

From stanley_reynolds at yahoo.com  Tue Oct 28 23:25:34 2008
From: stanley_reynolds at yahoo.com (Stanley Reynolds)
Date: Tue, 28 Oct 2008 16:25:34 -0700 (PDT)
Subject: [time-nuts] firmware bug ???
Message-ID: <561996.32646.qm@web30304.mail.mud.yahoo.com>

OPPS fixed bad link, sorry




________________________________
From: Stanley Reynolds <stanley_reynolds at yahoo.com>
To: Discussion of precise time and frequency measurement <time-nuts at febo.com>
Sent: Tuesday, October 28, 2008 6:22:15 PM
Subject: Re: [time-nuts] firmware bug ???

Follow up I checked the?IRIG-B Out and it has the same 73 days, if I can interface a new GPS module wonder if that would fix the?"GPS Week Number Rollover (WNRO)" http://leapsecond.com/notes/gpswnro.htmt? that?I think I have ?
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and follow the instructions there.

From stanley_reynolds at yahoo.com  Tue Oct 28 23:27:58 2008
From: stanley_reynolds at yahoo.com (Stanley Reynolds)
Date: Tue, 28 Oct 2008 16:27:58 -0700 (PDT)
Subject: [time-nuts] firmware bug ???
Message-ID: <615151.78985.qm@web30305.mail.mud.yahoo.com>






________________________________
From: Stanley Reynolds <stanley_reynolds at yahoo.com>
To: Discussion of precise time and frequency measurement <time-nuts at febo.com>
Sent: Tuesday, October 28, 2008 6:25:34 PM
Subject: Re: [time-nuts] firmware bug ???
one more time :-)
OPPS almost fixed bad link, sorry




________________________________
From: Stanley Reynolds <stanley_reynolds at yahoo.com>
To: Discussion of precise time and frequency measurement <time-nuts at febo.com>
Sent: Tuesday, October 28, 2008 6:22:15 PM
Subject: Re: [time-nuts] firmware bug ???

Follow up I checked the?IRIG-B Out and it has the same 73 days, if I can interface a new GPS module wonder if that would fix the?"GPS Week Number Rollover (WNRO)" http://leapsecond.com/notes/gpswnro.htm? that?I think I have ?
_______________________________________________
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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From stanley_reynolds at yahoo.com  Tue Oct 28 23:31:05 2008
From: stanley_reynolds at yahoo.com (Stanley Reynolds)
Date: Tue, 28 Oct 2008 16:31:05 -0700 (PDT)
Subject: [time-nuts] firmware bug ???
Message-ID: <75134.27562.qm@web30301.mail.mud.yahoo.com>

My last try, if the link doesn't work then maybe I should give up !!!



________________________________

From: Stanley Reynolds <stanley_reynolds at yahoo.com>
To: Discussion of precise time and frequency measurement <time-nuts at febo.com>
Sent: Tuesday, October 28, 2008 6:27:58 PM
Subject: Re: [time-nuts] firmware bug ???

one more time :-)

OPPS almost fixed bad link, sorry




________________________________
From: Stanley Reynolds <stanley_reynolds at yahoo.com>
To: Discussion of precise time and frequency measurement <time-nuts at febo.com>
Sent: Tuesday, October 28, 2008 6:22:15 PM
Subject: Re: [time-nuts] firmware bug ???

Follow up I checked the?IRIG-B Out and it has the same 73 days, if I can interface a new GPS module wonder if that would fix the?"GPS Week Number Rollover (WNRO)" http://leapsecond.com/notes/gpswnro.htm that?I think I have ?

_______________________________________________
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.






________________________________
From: Stanley Reynolds <stanley_reynolds at yahoo.com>
To: Discussion of precise time and frequency measurement <time-nuts at febo.com>
Sent: Tuesday, October 28, 2008 6:25:34 PM
Subject: Re: [time-nuts] firmware bug ???

From GandalfG8 at aol.com  Tue Oct 28 23:34:10 2008
From: GandalfG8 at aol.com (GandalfG8 at aol.com)
Date: Tue, 28 Oct 2008 19:34:10 EDT
Subject: [time-nuts] firmware bug ???
Message-ID: <cef.45842843.3638fb72@aol.com>

 
In a message dated 28/10/2008 23:31:38 GMT Standard Time,  
stanley_reynolds at yahoo.com writes:

My last  try, if the link doesn't work then maybe I should give up  !!!


Don't give up too soon.....
I just sent you a copy of the 8820A manual:-)
 
regards
 
Nigel
GM8PZR

From stanley_reynolds at yahoo.com  Wed Oct 29 00:05:00 2008
From: stanley_reynolds at yahoo.com (Stanley Reynolds)
Date: Tue, 28 Oct 2008 17:05:00 -0700 (PDT)
Subject: [time-nuts] firmware bug ???
Message-ID: <716642.10094.qm@web30305.mail.mud.yahoo.com>

Nigel Thank you for the Manual, yes it will help ! Was not giving up on the GPSDO just trying to fix the bad link, my fat fingers make it about as easy as surface mount PCBs 





________________________________
From: "GandalfG8 at aol.com" <GandalfG8 at aol.com>
To: time-nuts at febo.com
Sent: Tuesday, October 28, 2008 6:34:10 PM
Subject: Re: [time-nuts] firmware bug ???


In a message dated 28/10/2008 23:31:38 GMT Standard Time,? 
stanley_reynolds at yahoo.com writes:

My last? try, if the link doesn't work then maybe I should give up? !!!


Don't give up too soon.....
I just sent you a copy of the 8820A manual:-)

regards

Nigel
GM8PZR
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To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.

From biwa at att.net  Wed Oct 29 00:13:18 2008
From: biwa at att.net (Burt I. Weiner)
Date: Tue, 28 Oct 2008 17:13:18 -0700
Subject: [time-nuts] Sudden relief...
In-Reply-To: <mailman.5.1225238705.13535.time-nuts@febo.com>
References: <mailman.5.1225238705.13535.time-nuts@febo.com>
Message-ID: <mailman.0.1225239205.13532.time-nuts@febo.com>

Barfage.  I hate when that happens!

Burt

At 05:05 PM 10/28/2008, you wrote:
>I think I found the bug; somehow the web server and mailman processes
>weren't able to write in each other's files, which caused various forms
>of barfage.  Don't know why it suddenly broke, though...

Burt I. Weiner Associates
Broadcast Technical Services
Glendale, California U.S.A.
biwa at att.net
K6OQK 



From GandalfG8 at aol.com  Wed Oct 29 00:24:09 2008
From: GandalfG8 at aol.com (GandalfG8 at aol.com)
Date: Tue, 28 Oct 2008 20:24:09 EDT
Subject: [time-nuts] firmware bug ???
Message-ID: <d60.38513f29.36390729@aol.com>

 
In a message dated 29/10/2008 00:05:34 GMT Standard Time,  
stanley_reynolds at yahoo.com writes:

Was not  giving up on the GPSDO just trying to fix the bad link, my fat 
fingers make it  about as easy as surface mount PCBs 



LOL
 
I never have any problems with surface mount PCBs.......
just the components that go on them:-)

From swithrow at idcomm.com  Wed Oct 29 02:07:46 2008
From: swithrow at idcomm.com (Skip Withrow)
Date: Tue, 28 Oct 2008 20:07:46 -0600
Subject: [time-nuts] Anyone with information on STLN4096A / HP Z3817 ?
Message-ID: <20081029020746.EC0BF394089@mailhost.idcomm.com>


Thanks for all the time-nut information on the McCoy OSC92 pinout 
identification, it indeed does appear to be the same as the Isotemp OCXO134. 

Now for the next time-nuts challenge.  I also have a Motorola STLN4096A.  It 
appears to be an oscillator used in some kind of telecom equipment.  The 
really neat part is that it contains an H-P E1938A (I also know that some 
versions also came with the FEI 5680 rubidium)!  The E1938A has the DB-25 on 
the other side of the board (and opposite sex) than the one sent to me by 
Rick K., but some work making a jumper and it works in my Shera GPSDO just 
dandy. The other two boards in the three-board set are also H-P and marked 
with a Z3817-xxxxx part number (one is the power supply board and one is a 
processor board). 

Now for the time nuts help.  Any information on this beast?  There are two 
DB connectors on the unit, the DB-9 (marked MMI) is RS-232 and seems to talk 
SCPI.  Anyone have the command set?  Is this a repackaged Z3815?  The other 
connector (DB-25, marked TIB) is to the power supply board.  I have 
identified the (18-36V) power supply pins, but there are other I/O's - 
including a 1pps.  And I would imagine the 10MHz out.  Does this unit also 
interface to a GPS receiver and is it already a GPSDO (minus the GPS 
receiver)? 

As always, thanks in advance.  It is amazing the depth of knowledge of the 
collective time-nuts community. 

Regards,
Skip Withrow


From brice at weaponeer.com  Wed Oct 29 04:54:58 2008
From: brice at weaponeer.com (brice at weaponeer.com)
Date: Wed, 29 Oct 2008 04:54:58 +0000
Subject: [time-nuts] TRAK / Magnavox GPS
Message-ID: <W5576214095305151225256098@webmail32>

 My last mail crashed, it may be there and posted. Simplify, Does the Trak unit have a integrated or seperate Magnavox board? The front panel damage looks minor but may be worse than you think. TRAK stuff is cool but troublesome. I may have some parts.
Cheers, Bill




From stanley_reynolds at yahoo.com  Wed Oct 29 05:14:56 2008
From: stanley_reynolds at yahoo.com (Stanley Reynolds)
Date: Tue, 28 Oct 2008 22:14:56 -0700 (PDT)
Subject: [time-nuts] TRAK / Magnavox GPS
Message-ID: <862389.2999.qm@web30302.mail.mud.yahoo.com>

Bill

The Magnavox board is separate with a trak interface/power regulator board mounted on top it is on the front right side between the power supply and front panel behind the keypad. Note the select key top?is missing but still works. I have dissembled the lcd module and wiped the PCB board to LCD panel connections which restored some of the panel but not enough to be useful. Going on a hunch I've ordered a HP laser jet III panel which has a similar display with the same manufacturer part number.

Stanley




________________________________
From: "brice at weaponeer.com" <brice at weaponeer.com>
To: time-nuts at febo.com
Sent: Tuesday, October 28, 2008 11:54:58 PM
Subject: Re: [time-nuts] TRAK / Magnavox GPS

My last mail crashed, it may be there and posted. Simplify, Does the Trak unit have a integrated or seperate Magnavox board? The front panel damage looks minor but may be worse than you think. TRAK stuff is cool but troublesome. I may have some parts.
Cheers, Bill



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and follow the instructions there.

From nhbbobb at gmail.com  Wed Oct 29 07:04:30 2008
From: nhbbobb at gmail.com (bbobb mokai)
Date: Wed, 29 Oct 2008 15:04:30 +0800
Subject: [time-nuts] New Cool on ebay Hp Z3805A,
	Now forget Hp Z3816A and Hp Z3801A
Message-ID: <3eb99ee60810290004y6afa9319k594be20fc4a32802@mail.gmail.com>

Hello

i am fluke.l

Now cool tools.....in my store now

ebay item  NO 290271053032

QTY price just contract me by Email

Thanks
Bob




Symmetricom  Z3805A 16 channels GPS 10mhz high quality frequency/time
standards/ 1ppS

let me tell you how different it from the Hp Z3801 or Z3816A

1.it made in 2004 years,only use as standard in Korea.(HP Z3801A or Z3816A
made in 2000 year ) (most only power on Not over30 times ,it will recored in
the flash...)
2.it come with the 16 channels GPS module (made by furuno  in japan ) <Hp
Z3801A 6 channels ,Hp Z3816A 8 channels ,made by Motorola in USA>
3 The Hp Z3801A just come with one 10mhz,and Hp Z3816A come with the Two
10mhz and Two 1PPS.ONLY 1 RS232
But My Z3805A come with Two 10mhz and Two 1PPS Two RS422.and
base the information from Korea


also come with
 E1/T1 Output because it provides can be reused for various purposes on the
Network.


4.Base from the pic below you will find the  Improve to others

From df6jb at ulrich-bangert.de  Wed Oct 29 08:07:08 2008
From: df6jb at ulrich-bangert.de (Ulrich Bangert)
Date: Wed, 29 Oct 2008 09:07:08 +0100
Subject: [time-nuts] labview, gpib, gps ,
	logging data and lost data points!!
In-Reply-To: <4906594B.7060601@stny.rr.com>
Message-ID: <E9B9FF88377644FD857D74210B8753ED@athlon>

Norman,

what you are going to do requires a tight timing:

1) Because of the nature of the M12+'s messages their end is not easily
detected (<cr> and/or <line feed> may be WITHIN the messages due to
their halfbinary nature). A method would be to detect "no activity" on
the M12+'s transmit line for a time and then to decide that all messages
are received.

2) You need an fixed exact relation between the pps and the serial
messages, because the serial messages describe the situation for exactly
the NEXT pps.

3) The pps is 200 ms long.

4) 30 ms after the start of the pps the M12+ starts the serial
transmission for the NEXT pps.

4) Depending on which messages are send the duration of the messages may
vary, for the typical case of @@Ha, @@Hn and @@Bb the total duration is
abt 370 ms.

5) Due to 1)-5) a save way to do your measurement is: Make the start of
the pps to the start of your software activity, i.e.: 

a) Use the M12+'s pps as the STOP for your time interval counter, so
when you detect the start of the pps you can be sure that the TIC has
already performed it's last measurement. 

b) When you detect the the start of the pps immediately read Windows's
serial Buffer to have the complete messages available for the next pps.

I am sure this can be done with Labview but I know that problem solving
in Labview can sometimes be very tricky specially when tight timing is
necessary. Time as a physical entity is not well represented within the
"graphic programming language".

I would encourage you to go for a completely different way. The latest
version of my EZGPIB utility contains an example where the script 

a) waits for the pps of a M12+ (must be applied as an positive going
RS232 pulse on either DSR, CTS, DCD or RI) 

b) reads and then completely decodes @@Ha, @@Hn and @@Bb messages so
that for example the gps time and the sawtooth correction value are
readily available without hassle.

c) has a precise point at which the counter should be read

Best regards

Ulrich, DF6JB 

> -----Ursprungliche Nachricht-----
> Von: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] Im Auftrag von Norman J McSweyn
> Gesendet: Dienstag, 28. Oktober 2008 01:14
> An: Discussion of precise time and frequency measurement
> Betreff: [time-nuts] labview, gpib, gps , logging data and 
> lost data points!!
> 
> 
> Hi!
> I'm logging data from an HP 5335a (using it as a time 
> interval counter). 
> and from a Motorola gps board ( text data).
> The test setup is comparing the 1pps output from the gps board to a 
> divided (Thank you Dave Partridge!!!!!!) down 10 MHz from a Trimble 
> Thunderbolt. The text data is used to post process the 
> measurement from 
> the 5335a reflecting the 1pps error (+/- 15E-9). The ver is LV 8
> 
> Code description:
> Each instrument has it's own VI and I run them simultaneously, 
> collecting data and storing it in text files. The individual vi's are 
> for loops with the iterations being the number of seconds 
> that I want to 
> log. Inside the loop is obviously a delay. The data is time 
> stamped with 
> seconds enabled.
> 
> The problem is that somewhere in the 40k data points some (not all at 
> the same time or sometimes one here and there or sometimes a bunch at 
> once) aren't' collected.
> 
> Solutions that I've tried:
> Using the 1pps to drive the parallel port so that I've got a hardware 
> time hack. When I had both vi's in the same for loop things didn't go 
> well. Not really sure what happened. Separated them. Works well now 
> (except for the four or five lost data points in 40k)
> 
> Varying the time constant. It's helped lots, but I really 
> don't' want to 
> lose any data.
> 
> Have tried timed loops. Works fine with one process. Try to 
> do two (gpib 
> and serial for the gps) and it hangs the PC.
> 
> Solution that I think would work:
> A way of firmly triggering a start event with labview. I've 
> got a time 
> server so windoze time (or lack of it!) is not an issue. 
> (This may be an 
> issue. Played around with it. Turning off polling made a difference.)
> 
> I'm not really a programmer. Actually play with trains for a living. 
> Will be on vacation for the next week. Not much to do so I'll 
> be able to 
> play lots.
> Thoughts, questions, comments and humor greatly appreciated. 
> Thanks for your time, Norm n3ykf
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-> bin/mailman/listinfo/time-nuts
> and 
> follow the instructions there.
> 



From df6jb at ulrich-bangert.de  Wed Oct 29 08:09:38 2008
From: df6jb at ulrich-bangert.de (Ulrich Bangert)
Date: Wed, 29 Oct 2008 09:09:38 +0100
Subject: [time-nuts] Trimble Thinderbolt schematics
Message-ID: <E5711D0D322447F2BA7684BC11980CB1@athlon>

Gents,

sorry if this question has been asked before but do we have schematics
for our Trimble Thunderbolts available anywhere? Have been unable to
locate them so far.

TIA

Ulrich Bangert
www.ulrich-bangert.de
Ortholzer Weg 1
27243 Gross Ippener 



From brooke at pacific.net  Wed Oct 29 15:47:44 2008
From: brooke at pacific.net (Brooke Clarke)
Date: Wed, 29 Oct 2008 08:47:44 -0700
Subject: [time-nuts] labview, gpib, gps ,
	logging data and lost data points!!
In-Reply-To: <4906594B.7060601@stny.rr.com>
References: <4906594B.7060601@stny.rr.com>
Message-ID: <490885A0.2060208@pacific.net>

Hi Norman:

The way to do it in LabVIEW is to have a single VI running by itself that's the 
sole connection to the GPS data.  This VI looks for the end of one message AND 
the start of the next message, i.e. for Motorola <CR><LF>@@
Although it's possible for that to occur in the middle of data it only causes a 
hiccup at the beginning and will sort itself out.

Once you have found it, then the characters after the @@ are used to route the 
rest of the packet into a global table.  Note that there may be two or four 
message ID characters for the Motorola receivers.  Once you know which packet 
it is then you know how long it is so start looking for <CR><LF> where it's 
supposed to be then keep looking in case there's been some character stuffing.

Now you can have another VI running in parallel that just reads the global 
table of packets and processes each one (calls the @@ VIs).  This can be 
greatly simplified since the same VI can read many different packets because 
they all have the same number of variables of the same data types.  So you end 
up with a VI named for each @@ message and those call generic VIs that read the 
global table.

I did this many years ago to compare a hardware 1 PPS sawtooth corrector with 
the software method.
http://www.prc68.com/I/timefreq.shtml#Sawtoooth

Have Fun,

Brooke Clarke, N6GCE
http://www.prc68.com/P/Prod.html  Products I make and sell
http://www.prc68.com/Alpha.shtml  All my web pages listed based on html name
http://www.PRC68.com
http://www.precisionclock.com
http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Web Cam

Norman J McSweyn wrote:
> Hi!
> I'm logging data from an HP 5335a (using it as a time interval counter). 
> and from a Motorola gps board ( text data).
> The test setup is comparing the 1pps output from the gps board to a 
> divided (Thank you Dave Partridge!!!!!!) down 10 MHz from a Trimble 
> Thunderbolt. The text data is used to post process the measurement from 
> the 5335a reflecting the 1pps error (+/- 15E-9). The ver is LV 8
> 
> Code description:
> Each instrument has it's own VI and I run them simultaneously, 
> collecting data and storing it in text files. The individual vi's are 
> for loops with the iterations being the number of seconds that I want to 
> log. Inside the loop is obviously a delay. The data is time stamped with 
> seconds enabled.
> 
> The problem is that somewhere in the 40k data points some (not all at 
> the same time or sometimes one here and there or sometimes a bunch at 
> once) aren't' collected.
> 
> Solutions that I've tried:
> Using the 1pps to drive the parallel port so that I've got a hardware 
> time hack. When I had both vi's in the same for loop things didn't go 
> well. Not really sure what happened. Separated them. Works well now 
> (except for the four or five lost data points in 40k)
> 
> Varying the time constant. It's helped lots, but I really don't' want to 
> lose any data.
> 
> Have tried timed loops. Works fine with one process. Try to do two (gpib 
> and serial for the gps) and it hangs the PC.
> 
> Solution that I think would work:
> A way of firmly triggering a start event with labview. I've got a time 
> server so windoze time (or lack of it!) is not an issue. (This may be an 
> issue. Played around with it. Turning off polling made a difference.)
> 
> I'm not really a programmer. Actually play with trains for a living. 
> Will be on vacation for the next week. Not much to do so I'll be able to 
> play lots.
> Thoughts, questions, comments and humor greatly appreciated.
> Thanks for your time,
> Norm n3ykf
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 


From normn3ykf at stny.rr.com  Wed Oct 29 16:40:14 2008
From: normn3ykf at stny.rr.com (Norman J McSweyn)
Date: Wed, 29 Oct 2008 12:40:14 -0400
Subject: [time-nuts] labview, gpib, gps ,
	logging data and lost data points!!
In-Reply-To: <E9B9FF88377644FD857D74210B8753ED@athlon>
References: <E9B9FF88377644FD857D74210B8753ED@athlon>
Message-ID: <490891EE.3020600@stny.rr.com>

Ulrich,
Does EZ-GPIB support visa? I know there was a thread a few months back 
kicking around the idea.

The way the code is written now, I'm getting a response to @@Hn and 
parsing that.

The idea was to save the data in text files and post-process with excel.

Using the SRQ (and your idea as from the counter to generate a timing 
mark (to start the serial vi). This makes a lot of sense because I'll 
know that the data in the message will be for the next second 
(timestamped with this second)

Based on my observations, the gpib routine takes 300ms to complete. It's 
just setup, trigger and read. I'll have to change this.

There are two reasons for Labview. One is it's used quite a bit. The 
other is that the learing curve isn't quite as steep as C++ or VB.

Either way, you've given much to think about!
Thanks,
Norm n3ykf


From tomknox at nist.gov  Wed Oct 29 17:07:12 2008
From: tomknox at nist.gov (tomknox at nist.gov)
Date: Wed, 29 Oct 2008 13:07:12 -0400
Subject: [time-nuts] What is opt 06 on BVA8600
Message-ID: <20081029130712.32372vqs1om6g4e8@webmail.nist.gov>

Hi;
Anyone know what option 06 is on a Oscilloquartz 8600?
Thanks;
Thomas Knox







From Murray.Greenman at rakon.com  Wed Oct 29 17:25:56 2008
From: Murray.Greenman at rakon.com (Murray Greenman)
Date: Thu, 30 Oct 2008 06:25:56 +1300
Subject: [time-nuts] STLN4096A / HP Z3817
In-Reply-To: <mailman.3.1225281601.22721.time-nuts@febo.com>
References: <mailman.3.1225281601.22721.time-nuts@febo.com>
Message-ID: <BE50C3A72EBA61449C804B2C8B4AE381D059EA@NEPTUNE.rakon.net>

Skip,

How about sending me some photos of the unit? I know the Z3815A and
E1938A well, and if it's the same in different packaging, I'll be able
to tell.

73,
Murray ZL1BPU



From Jean-Louis.Oneto at obs-azur.fr  Wed Oct 29 17:37:51 2008
From: Jean-Louis.Oneto at obs-azur.fr (Jean-Louis Oneto)
Date: Wed, 29 Oct 2008 17:37:51 -0000
Subject: [time-nuts] What is opt 06 on BVA8600
References: <20081029130712.32372vqs1om6g4e8@webmail.nist.gov>
Message-ID: <8D6279D230F647E695E67E81612CBE9F@pcreopt>

Hi,
Extrapolating the short-term stability options for the 8607 ( 
http://www.oscilloquartz.ch/file/pdf/8607.pdf  bottom of page 2), it could 
be sigma-tau < 6e-14  for Tau=3.0s-30s @ 5MHz...
Hope that helps,
Have a nice day,
Jean-Louis Oneto
----- Original Message ----- 
From: <tomknox at nist.gov>
To: <time-nuts at febo.com>
Sent: Wednesday, October 29, 2008 5:07 PM
Subject: [time-nuts] What is opt 06 on BVA8600


> Hi;
> Anyone know what option 06 is on a Oscilloquartz 8600?
> Thanks;
> Thomas Knox
>
>
>
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there. 



From rputz at bnin.net  Wed Oct 29 23:46:38 2008
From: rputz at bnin.net (Rich and Marcia Putz)
Date: Wed, 29 Oct 2008 19:46:38 -0400
Subject: [time-nuts] Z3805 and Fluke.I
Message-ID: <003801c93a20$97383ee0$9d83e262@newiw112a268qp>

Hi ALL;

Since Fluke.I is now advertising on our forum, perhaps he should make special deal for all us for real time-nuts, like a Z3805 for $35 or so! What do the rest of you think?
Rich

From sar10538 at gmail.com  Thu Oct 30 02:43:05 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Thu, 30 Oct 2008 15:43:05 +1300
Subject: [time-nuts] Z3805 and Fluke.I
In-Reply-To: <003801c93a20$97383ee0$9d83e262@newiw112a268qp>
References: <003801c93a20$97383ee0$9d83e262@newiw112a268qp>
Message-ID: <1231b6a80810291943r7f9f60fcgdec4adad910f33af@mail.gmail.com>

2008/10/30 Rich and Marcia Putz <rputz at bnin.net>:
> Since Fluke.I is now advertising on our forum, perhaps he should make special deal for all us for real time-nuts, like a Z3805 for $35 or so! What do the rest of you think?

Does that include shipping?

73, Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From df6jb at ulrich-bangert.de  Thu Oct 30 07:24:18 2008
From: df6jb at ulrich-bangert.de (Ulrich Bangert)
Date: Thu, 30 Oct 2008 08:24:18 +0100
Subject: [time-nuts] labview, gpib, gps ,
	logging data and lost data points!!
In-Reply-To: <490891EE.3020600@stny.rr.com>
Message-ID: <2F5D1A1EAD16449A85D430A9C7FC3D41@athlon>

Norman,

> Does EZ-GPIB support visa?

Yes, it is not a complete implementation but it should be enough for
tasks like that.

> The idea was to save the data in text files and post-process 
> with excel.

Sure possible, but if the decoding can be done in realtime why not do
it.

> Based on my observations, the gpib routine takes 300ms to 
> complete. 

For my HP counters the rule applies: Once they are configured and you
can be sure that they have terminated a measurement (either because they
triggred the bus SRQ line or by knowing that they received a signal on
the stop input) you can ask for the result and you get it with high
speed, merely microseconds then milliseconds.

> There are two reasons for Labview. One is it's used quite a bit. The 
> other is that the learing curve isn't quite as steep as C++ or VB.

As I did already say: There is a readey to go example that performs the
complete decoding. The only prerequisite is a positive going pps on
either of the RS232 status input lines.

73s and my best regards
Ulrich, DF6JB

P.S.
I just received an feedback that the version of 2008-10-29 may contain a
bug. Please wait with a test of EZGPIB until a later version is
available.

> -----Ursprungliche Nachricht-----
> Von: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] Im Auftrag von Norman J McSweyn
> Gesendet: Mittwoch, 29. Oktober 2008 17:40
> An: Discussion of precise time and frequency measurement
> Betreff: Re: [time-nuts] labview, gpib, gps ,logging data and 
> lost data points!!
> 
> 
> Ulrich,
> Does EZ-GPIB support visa? I know there was a thread a few 
> months back 
> kicking around the idea.
> 
> The way the code is written now, I'm getting a response to @@Hn and 
> parsing that.
> 
> The idea was to save the data in text files and post-process 
> with excel.
> 
> Using the SRQ (and your idea as from the counter to generate a timing 
> mark (to start the serial vi). This makes a lot of sense because I'll 
> know that the data in the message will be for the next second 
> (timestamped with this second)
> 
> Based on my observations, the gpib routine takes 300ms to 
> complete. It's 
> just setup, trigger and read. I'll have to change this.
> 
> There are two reasons for Labview. One is it's used quite a bit. The 
> other is that the learing curve isn't quite as steep as C++ or VB.
> 
> Either way, you've given much to think about!
> Thanks,
> Norm n3ykf
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-> bin/mailman/listinfo/time-nuts
> and 
> follow the instructions there.
> 



From pfmonet at wanadoo.fr  Thu Oct 30 07:52:02 2008
From: pfmonet at wanadoo.fr (=?iso-8859-1?Q?Pierre-Fran=E7ois_=28f5bqp=5Fpfm=29?=)
Date: Thu, 30 Oct 2008 08:52:02 +0100
Subject: [time-nuts] Z3805 and Fluke.I
References: <003801c93a20$97383ee0$9d83e262@newiw112a268qp>
Message-ID: <00a601c93a64$65758130$4501a8c0@r44>

Hi All,

I think this is a great idea to replace my legacy Z3816A!...
I also hope they'll offer as a gift the software to drive it, and they 
should gratify Bill K8CU to modify his software GPSCON to support the Z3805 
if it's not done yet!... ;-))
35 bucs sems to be reasonable to me, these difficult financial days...
Considering also that these receivers are also legacies, certainly pulled 
off from legacy networks...

Best 73's to all of you.

pf, F5BQP



----- Original Message ----- 
From: "Rich and Marcia Putz" <rputz at bnin.net>
To: <time-nuts at febo.com>
Sent: Thursday, October 30, 2008 12:46 AM
Subject: [time-nuts] Z3805 and Fluke.I


>
> Hi ALL;
>
> Since Fluke.I is now advertising on our forum, perhaps he should make 
> special deal for all us for real time-nuts, like a Z3805 for $35 or so! 
> What do the rest of you think?
> Rich
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>
> __________ Information NOD32 3568 (20081030) __________
>
> Ce message a ete verifie par NOD32 Antivirus System.
> http://www.nod32.com
>
> 




From pfmonet at wanadoo.fr  Thu Oct 30 07:58:49 2008
From: pfmonet at wanadoo.fr (=?iso-8859-1?Q?Pierre-Fran=E7ois_=28f5bqp=5Fpfm=29?=)
Date: Thu, 30 Oct 2008 08:58:49 +0100
Subject: [time-nuts] Z3805 and Fluke.I
References: <003801c93a20$97383ee0$9d83e262@newiw112a268qp>
	<1231b6a80810291943r7f9f60fcgdec4adad910f33af@mail.gmail.com>
Message-ID: <00c501c93a65$57dcb600$4501a8c0@r44>


----- Original Message ----- 
From: "Steve Rooke" <sar10538 at gmail.com>
To: "Discussion of precise time and frequency measurement" 
<time-nuts at febo.com>
Sent: Thursday, October 30, 2008 3:43 AM
Subject: Re: [time-nuts] Z3805 and Fluke.I


>
> 2008/10/30 Rich and Marcia Putz <rputz at bnin.net>:
>> Since Fluke.I is now advertising on our forum, perhaps he should make 
>> special deal for all us for real time-nuts, like a Z3805 for $35 or so! 
>> What do the rest of you think?
>
> Does that include shipping?
>

I don't think so...
I would pay extra for that... ;-))
But from China it would overshoot the price...

Best 73's
pf, F5BQP


> 73, Steve
> -- 
> Steve Rooke - ZL3TUV & G8KVD
> Omnium finis imminet
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to 
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>
>
> __________ Information NOD32 3568 (20081030) __________
>
> Ce message a ete verifie par NOD32 Antivirus System.
> http://www.nod32.com
>
> 




From rexa at sonic.net  Thu Oct 30 10:02:00 2008
From: rexa at sonic.net (Rex)
Date: Thu, 30 Oct 2008 03:02:00 -0700
Subject: [time-nuts] Z3805 and Fluke.I
In-Reply-To: <00a601c93a64$65758130$4501a8c0@r44>
References: <003801c93a20$97383ee0$9d83e262@newiw112a268qp>
	<00a601c93a64$65758130$4501a8c0@r44>
Message-ID: <49098618.5020307@sonic.net>

Pierre-Fran?ois (f5bqp_pfm) wrote:
> Hi All,
>
> I think this is a great idea to replace my legacy Z3816A!...
> I also hope they'll offer as a gift the software to drive it, and they 
> should gratify Bill K8CU to modify his software GPSCON to support the Z3805 
> if it's not done yet!... ;-))
> 35 bucs sems to be reasonable to me, these difficult financial days...
> Considering also that these receivers are also legacies, certainly pulled 
> off from legacy networks...
>
> Best 73's to all of you.
>
> pf, F5BQP
>
>
>   

$35 would be great, but I suspect it may be a good bit less than the 
current owner has invested. But I can't, myself, see paying a bit more 
than double what I invested in my Z3816A. Might be ok for some, but 
seems way pricey vs the current available Thunderbolts unless there is 
some major advantage that I don't know about. Lost the link, was it 
rs422 control port? I don't see that as an advantage. The 3816 talks to 
standard serial without modification.

I think what you have is pretty good. Not all that much legacy vs most 
of my favorite stuff. Can't see why it would wear out soon. No Cs or Rb.

His listing does short the Z3816A by a few ports in the comparison. 
There are 4 1 PPS ports, not two and there are also 4 19.6608 MHz ports. 
If you don't have use for the 19.6 ports, I did find a way to convert 
mine to make them 10 MHz square wave outputs. See:
http://www.xertech.net/Projects/Z3816/3816_mod.html

This gives the 3816 these outputs: standard 2 10 MHz sine, 4 1 PPS pulse 
and then 4 10 MHz square wave.

For those who can afford, happy shopping.   For any who have Z3816A's 
and want more 10 MHz, I hope my mod works for you.



From Stefan.Heinzmann at alcnetworx.de  Thu Oct 30 11:42:00 2008
From: Stefan.Heinzmann at alcnetworx.de (Heinzmann, Stefan  (ALC NetworX GmbH))
Date: Thu, 30 Oct 2008 12:42:00 +0100
Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
In-Reply-To: <E1KtXgE-00080i-7k@meow.febo.com>
References: <D7B1B5F4F3F27A4CB073BF422331203F0DD74643CD@Exchange1.lawo.de>
	<E1KtXgE-00080i-7k@meow.febo.com>
Message-ID: <D7B1B5F4F3F27A4CB073BF422331203F0DD78793B0@Exchange1.lawo.de>

Thanks to all who replied, and sorry for the delay. I was away and unfortunately unable to follow the discussion until today.


From bogus@does.not.exist.com  Tue Oct 28 16:59:30 2008
From: bogus@does.not.exist.com ()
Date: Tue, 28 Oct 2008 16:59:30 -0000
Subject: No subject
Message-ID: <mailman.1.1225366927.13532.time-nuts@febo.com>

or measuring the ADEV when employing the picket fence technique. A direct m=
easurement is prevented by the counter's dead-time. Apart from a suitable d=
ivider, I'd probably need to write my own piece of software for massaging t=
he data so that it can be used for an ADEV plot. Unless of course there is =
some software readily available that includes handling of the picket fence =
technique.

My other idea of using two counters in lockstep, so that they measure alter=
nate periods of the signal, hasn't been commented on. Is it a silly idea, a=
part from the fact that it needs two counters? Has anyone tried anything li=
ke it?

Thanks and Cheers
Stefan


-----Urspr=FCngliche Nachricht-----
Von: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] Im Auft=
rag von Tom Duckworth
Gesendet: Samstag, 25. Oktober 2008 03:11
An: 'Discussion of precise time and frequency measurement'
Betreff: Re: [time-nuts] Measuring ADEV with a PM6681 or CNT-81

Stefan,



Well, I have been sort of staying out of the recent discussions regarding
oscillator stability measurements, ADEV, etc., but here goes my two cents
worth. I hope it doesn't muddy the waters too much and is somewhat helpful.



There is a fundamental problem with trying to do ADEV (Allan Deviation) wit=
h
a counter that has a gated measurement engine (all standard counters). The
problem is that when the count engine gate closes (so the counter can
compute the number of events, report the result as a frequency, and clear
its registers), the counter is blind (dead time) to any signal at the input=
.
Allan deviation REQUIRES than a minimum number of measurements be made
back-to-back (no dead time between measurements) in order to capture
nondeterministic fluctuations of the signal you're trying to measure. This
requires a measuring device (counter) that continuously records ALL events.
It does this by time-stamping a fixed period in a separate register in the
counter along with the input register (the signal being measured), and a
time-base register that records the frequency the signal is to be compared
with. There is no 'gate' as such in a time-stamping counter.



Most stability measurements, longer than say 100 seconds, are made in the
frequency domain because energy changes, as a result of heat, are by far th=
e
predominate cause of stability (aging) issues (see below). Stability issues
within shorter time periods, say <100 sec., are often nondeterministic, and
cannot be accurately quantified in the frequency domain, but must be
measured in the time domain, using statistical weighting. In other words,
unpredictable, and often little understood, events (Shot and thermal noise
in the active devices, random variations in the frequency-determining
elements, cosmic rays, etc.) often predominate short term stability
measurements and must be described statistically, as their occurrence and
duration are random. Allan deviation is a widely accepted time-domain
statistical measurement whose calculated results compare well with the more
common frequency domain measurement of longer time periods.



Allan deviation measurements are based on the sample variance of the
fractional-frequency fluctuations. Without specifying the number of samples
N, and the repetition interval T, for measurements of duration t, the
measure of frequency stability is dimensionless and would converge to a
meaningless limit. Secondly, some actual noise processes contain substantia=
l
fractions of the total noise power in the instantaneous fractional-frequenc=
y
range below one cycle per year. In order to improve compatibility of data,
it is important to specify a particular N and T. The Allan variance chooses
N=3D2 and T=3Dt (i.e. no dead time between measurements). A good estimate c=
an be
obtained by a limited number, m, of measurements (m=3D*100). Root Allen
variance is expressed as a quantity divided by the square of the
measurements of duration t, (i.e., 3 x 10-11/*t).

.

Classical variance diverges for commonly observed noise processes, such as
random walk (i.e., the variance increases with an increasing number of data
points). The advantage with the Allan variance is that it:

*           converges for all noise processes observed in precision
oscillators;

*           has straightforward relationship to power law spectral density
(spectral density of the frequency fluctuations);

*           is easy to compute, and;

*           is faster and more accurate in estimating noise processes than
the Fast Fourier Transform.



Aging in quartz crystal oscillators is caused by changes in either the
quartz crystal itself or the associated components found in the oscillator
assembly. Aging is the result of a combination of several factors having
complex, and only partially understood, components that effect the aging
specification. Effects can include the cut (orientation) of the crystal;
vibration modes; frequency of cut size; temperature of operation and
variations of temperature; drive energy; gravity; physical orientation;
shock; electromagnetic interference; diffusion of impurities and the
outgassing of the quartz crystal; the glass or ceramic base; the adhesive
used to mount the quartz; metal migration from the electrodes into the
quartz surface; stress relief of the crystal mounts; changes of electric
component values over time; and, voltage regulation.



This is probably more information than you really wanted, but oh well,
enjoy.



Tom

Tom Duckworth

510-886-1396





-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Heinzmann, Stefan (ALC NetworX GmbH)
Sent: Friday, October 24, 2008 2:03 AM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Measuring ADEV with a PM6681 or CNT-81



Thanks, Tom!



Apart from the specifics with TimeView, how does one go about measuring ADE=
V
with a counter that does have a dead-time? Are there tricks that can be
played, either with a special measurement setup or with some data
postprocessing? Or with two counters that are somehow made to cooperate?



Sorry if I'm asking the obvious, you can see that I'm a greenhorn. ;-)



Cheers

Stefan



-----Urspr=FCngliche Nachricht-----

Von: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] Im
Auftrag von Tom Duckworth

Gesendet: Donnerstag, 23. Oktober 2008 22:19

An: 'Discussion of precise time and frequency measurement'

Betreff: Re: [time-nuts] Measuring ADEV with a PM6681 or CNT-81



Stefan,



I am retired from Pendulum Instruments and could answer your question but I

have instead refered your question to a current engineer with the company

and you should receive an answer from them shortly. They are the experts fo=
r

this question.



Tom

Tom Duckworth

510-886-1396





-----Original Message-----

From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On

Behalf Of Heinzmann, Stefan (ALC NetworX GmbH)

Sent: Thursday, October 23, 2008 10:12 AM

To: time-nuts at febo.com

Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81



Hi all,



I hope you can clear up some confusion that I have regarding ADEV

measurement. I was under the impression that you need a counter that is abl=
e

to timestamp each rising edge of the clock under test, or equivalently

measure period time continuously with no dead time. Now, while the CNT-90

can do this, the CNT-81 ( =3D PM6681 ) can't. Still, a message last Decembe=
r

to the list here

(http://www.mail-archive.com/time-nuts at febo.com/msg10963.html) seems to

indicate that using TimeView you can have ADEV plotted with the "lesser"

model, too. I have a PM6681 and TimeView, but I couldn't find out how to do

it. Maybe it can't be done.



So what's the deal on this? Can it be done, with or without TimeView, and i=
f

yes, how? If this has been answered earlier, a link would be just fine.



Thanks and cheers

Stefan



_______________________________________________

time-nuts mailing list -- time-nuts at febo.com

To unsubscribe, go to

https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

and follow the instructions there.





_______________________________________________

time-nuts mailing list -- time-nuts at febo.com

To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

and follow the instructions there.



_______________________________________________

time-nuts mailing list -- time-nuts at febo.com

To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

and follow the instructions there.

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nu=
ts
and follow the instructions there.


From sar10538 at gmail.com  Thu Oct 30 11:53:45 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Fri, 31 Oct 2008 00:53:45 +1300
Subject: [time-nuts] Time-zones and World time..
Message-ID: <1231b6a80810300453h117e2ef6o929e23f40c3ed236@mail.gmail.com>

Hi,

I've been under the radar for a while so have not been able to keep up
with the threads I was contributing to but that has been done to death
and I will drop them. I've been very interested in reading peoplels
thoughts on time-zones. Has there been any moves to adopt a common
time for all countries in the world so as to alleviate the
difficulties in dealing with time-zones?" I know there was the idea of
Internet-time going around some time ago but I think that seems to
have died a death. Thinking about it, what's the problem of adapting
to daily life which is shifted by some number of hours off the clock.
If we all used UTC everyone around the world would know when a certain
time was in their own day. In my case for New Zealand, +12 hours would
probably be adopted for the country, so AM becomes PM and I'd get up
at 7PM (still that's not much different from now :) instead of AM.

I guess the question is, what's the likely-hood of a world standard
time being adopted (sort of like Star Trek)?

73
Steve - ZL3TUV
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From df6jb at ulrich-bangert.de  Thu Oct 30 12:02:53 2008
From: df6jb at ulrich-bangert.de (Ulrich Bangert)
Date: Thu, 30 Oct 2008 13:02:53 +0100
Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
In-Reply-To: <D7B1B5F4F3F27A4CB073BF422331203F0DD78793B0@Exchange1.lawo.de>
Message-ID: <FFE32839C7B34D04B2CE28F8DBD502E2@athlon>

Stefan,

> Apart from a suitable divider, I'd....

If you a dedicated follower of PIC microcontrollers you find something
suitable here on Tom's pages

http://www.leapsecond.com/pages/ppsdiv/

Otherwise if you like AVRs then you can find something on my pages

http://www.ulrich-bangert.de/html/downloads.html

Suitable sine to ttl circuits designed by Bruce Griffiths are to be
found at 

http://www.ko4bb.com/~bruce/CLKSHPR.html

Best regards
Ulrich 

> -----Urspr?ngliche Nachricht-----
> Von: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] Im Auftrag von Heinzmann, 
> Stefan (ALC NetworX GmbH)
> Gesendet: Donnerstag, 30. Oktober 2008 12:42
> An: Discussion of precise time and frequency measurement
> Betreff: [!! SPAM] Re: [time-nuts] Measuring ADEV with a 
> PM6681 or CNT-81
> 
> 
> Thanks to all who replied, and sorry for the delay. I was 
> away and unfortunately unable to follow the discussion until today.
> 
> From Tom's comments and others I extract that the PM6681 can 
> only be used for measuring the ADEV when employing the picket 
> fence technique. A direct measurement is prevented by the 
> counter's dead-time. Apart from a suitable divider, I'd 
> probably need to write my own piece of software for massaging 
> the data so that it can be used for an ADEV plot. Unless of 
> course there is some software readily available that includes 
> handling of the picket fence technique.
> 
> My other idea of using two counters in lockstep, so that they 
> measure alternate periods of the signal, hasn't been 
> commented on. Is it a silly idea, apart from the fact that it 
> needs two counters? Has anyone tried anything like it?
> 
> Thanks and Cheers
> Stefan
> 
> 
> -----Urspr?ngliche Nachricht-----
> Von: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] Im Auftrag von Tom Duckworth
> Gesendet: Samstag, 25. Oktober 2008 03:11
> An: 'Discussion of precise time and frequency measurement'
> Betreff: Re: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
> 
> Stefan,
> 
> 
> 
> Well, I have been sort of staying out of the recent 
> discussions regarding oscillator stability measurements, 
> ADEV, etc., but here goes my two cents worth. I hope it 
> doesn't muddy the waters too much and is somewhat helpful.
> 
> 
> 
> There is a fundamental problem with trying to do ADEV (Allan 
> Deviation) with a counter that has a gated measurement engine 
> (all standard counters). The problem is that when the count 
> engine gate closes (so the counter can compute the number of 
> events, report the result as a frequency, and clear its 
> registers), the counter is blind (dead time) to any signal at 
> the input. Allan deviation REQUIRES than a minimum number of 
> measurements be made back-to-back (no dead time between 
> measurements) in order to capture nondeterministic 
> fluctuations of the signal you're trying to measure. This 
> requires a measuring device (counter) that continuously 
> records ALL events. It does this by time-stamping a fixed 
> period in a separate register in the counter along with the 
> input register (the signal being measured), and a time-base 
> register that records the frequency the signal is to be 
> compared with. There is no 'gate' as such in a time-stamping counter.
> 
> 
> 
> Most stability measurements, longer than say 100 seconds, are 
> made in the frequency domain because energy changes, as a 
> result of heat, are by far the predominate cause of stability 
> (aging) issues (see below). Stability issues within shorter 
> time periods, say <100 sec., are often nondeterministic, and 
> cannot be accurately quantified in the frequency domain, but 
> must be measured in the time domain, using statistical 
> weighting. In other words, unpredictable, and often little 
> understood, events (Shot and thermal noise in the active 
> devices, random variations in the frequency-determining 
> elements, cosmic rays, etc.) often predominate short term 
> stability measurements and must be described statistically, 
> as their occurrence and duration are random. Allan deviation 
> is a widely accepted time-domain statistical measurement 
> whose calculated results compare well with the more common 
> frequency domain measurement of longer time periods.
> 
> 
> 
> Allan deviation measurements are based on the sample variance 
> of the fractional-frequency fluctuations. Without specifying 
> the number of samples N, and the repetition interval T, for 
> measurements of duration t, the measure of frequency 
> stability is dimensionless and would converge to a 
> meaningless limit. Secondly, some actual noise processes 
> contain substantial fractions of the total noise power in the 
> instantaneous fractional-frequency range below one cycle per 
> year. In order to improve compatibility of data, it is 
> important to specify a particular N and T. The Allan variance 
> chooses N=2 and T=t (i.e. no dead time between measurements). 
> A good estimate can be obtained by a limited number, m, of 
> measurements (m=*100). Root Allen variance is expressed as a 
> quantity divided by the square of the measurements of 
> duration t, (i.e., 3 x 10-11/*t).
> 
> .
> 
> Classical variance diverges for commonly observed noise 
> processes, such as random walk (i.e., the variance increases 
> with an increasing number of data points). The advantage with 
> the Allan variance is that it:
> 
> *           converges for all noise processes observed in precision
> oscillators;
> 
> *           has straightforward relationship to power law 
> spectral density
> (spectral density of the frequency fluctuations);
> 
> *           is easy to compute, and;
> 
> *           is faster and more accurate in estimating noise 
> processes than
> the Fast Fourier Transform.
> 
> 
> 
> Aging in quartz crystal oscillators is caused by changes in 
> either the quartz crystal itself or the associated components 
> found in the oscillator assembly. Aging is the result of a 
> combination of several factors having complex, and only 
> partially understood, components that effect the aging 
> specification. Effects can include the cut (orientation) of 
> the crystal; vibration modes; frequency of cut size; 
> temperature of operation and variations of temperature; drive 
> energy; gravity; physical orientation;
> shock; electromagnetic interference; diffusion of impurities 
> and the outgassing of the quartz crystal; the glass or 
> ceramic base; the adhesive used to mount the quartz; metal 
> migration from the electrodes into the quartz surface; stress 
> relief of the crystal mounts; changes of electric component 
> values over time; and, voltage regulation.
> 
> 
> 
> This is probably more information than you really wanted, but 
> oh well, enjoy.
> 
> 
> 
> Tom
> 
> Tom Duckworth
> 
> 510-886-1396
> 
> 
> 
> 
> 
> -----Original Message-----
> From: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Heinzmann, 
> Stefan (ALC NetworX GmbH)
> Sent: Friday, October 24, 2008 2:03 AM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
> 
> 
> 
> Thanks, Tom!
> 
> 
> 
> Apart from the specifics with TimeView, how does one go about 
> measuring ADEV with a counter that does have a dead-time? Are 
> there tricks that can be played, either with a special 
> measurement setup or with some data postprocessing? Or with 
> two counters that are somehow made to cooperate?
> 
> 
> 
> Sorry if I'm asking the obvious, you can see that I'm a greenhorn. ;-)
> 
> 
> 
> Cheers
> 
> Stefan
> 
> 
> 
> -----Urspr?ngliche Nachricht-----
> 
> Von: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] Im Auftrag von Tom Duckworth
> 
> Gesendet: Donnerstag, 23. Oktober 2008 22:19
> 
> An: 'Discussion of precise time and frequency measurement'
> 
> Betreff: Re: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
> 
> 
> 
> Stefan,
> 
> 
> 
> I am retired from Pendulum Instruments and could answer your 
> question but I
> 
> have instead refered your question to a current engineer with 
> the company
> 
> and you should receive an answer from them shortly. They are 
> the experts for
> 
> this question.
> 
> 
> 
> Tom
> 
> Tom Duckworth
> 
> 510-886-1396
> 
> 
> 
> 
> 
> -----Original Message-----
> 
> From: time-nuts-bounces at febo.com 
> [mailto:time-nuts-bounces at febo.com] On
> 
> Behalf Of Heinzmann, Stefan (ALC NetworX GmbH)
> 
> Sent: Thursday, October 23, 2008 10:12 AM
> 
> To: time-nuts at febo.com
> 
> Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
> 
> 
> 
> Hi all,
> 
> 
> 
> I hope you can clear up some confusion that I have regarding ADEV
> 
> measurement. I was under the impression that you need a 
> counter that is able
> 
> to timestamp each rising edge of the clock under test, or equivalently
> 
> measure period time continuously with no dead time. Now, 
> while the CNT-90
> 
> can do this, the CNT-81 ( = PM6681 ) can't. Still, a message 
> last December
> 
> to the list here
> 
> (http://www.mail-archive.com/time-nuts at febo.com/msg10963.html)
>  seems to
> 
> indicate that using TimeView you can have ADEV plotted with 
> the "lesser"
> 
> model, too. I have a PM6681 and TimeView, but I couldn't find 
> out how to do
> 
> it. Maybe it can't be done.
> 
> 
> 
> So what's the deal on this? Can it be done, with or without 
> TimeView, and if
> 
> yes, how? If this has been answered earlier, a link would be 
> just fine.
> 
> 
> 
> Thanks and cheers
> 
> Stefan
> 
> 
> 
> _______________________________________________
> 
> time-nuts mailing list -- time-nuts at febo.com
> 
> To unsubscribe, go to
> 
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

and follow the instructions there.





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From dave.g0dja at tiscali.co.uk  Thu Oct 30 12:12:08 2008
From: dave.g0dja at tiscali.co.uk (David Ackrill)
Date: Thu, 30 Oct 2008 12:12:08 +0000
Subject: [time-nuts] Time-zones and World time..
In-Reply-To: <1231b6a80810300453h117e2ef6o929e23f40c3ed236@mail.gmail.com>
References: <1231b6a80810300453h117e2ef6o929e23f40c3ed236@mail.gmail.com>
Message-ID: <4909A498.6020005@tiscali.co.uk>

Steve Rooke wrote:

> I guess the question is, what's the likely-hood of a world standard
> time being adopted (sort of like Star Trek)?

I would say it's very unlikely to happen.  People tend to prefer the 
time in their area to match up with the day.  So, having the sun come up 
at 7pm wouldn't suit a lot of people.

Recently the islanders on Jersey rejected a proposal to move to Central 
European Time (CET) see 
http://www.timeanddate.com/news/time/jersey-time-zone-referendum.html

Dave



From sar10538 at gmail.com  Thu Oct 30 12:46:07 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Fri, 31 Oct 2008 01:46:07 +1300
Subject: [time-nuts] What's the time Mr Wolf...
Message-ID: <1231b6a80810300546s72af8bffu9892113782bd7b2@mail.gmail.com>

Hi,

This may have already been covered in this group so please excuse me
for not combing the archives. I could Google for this but I'll get a
quicker answer here and I know it will be the correct one.

!) Who decides on what is the correct time?
2) Is the time standard stored on one master grandfather clock?
3) As (2) is unlikely, if a number of clocks are involved, are they in
different countries?
4) As (3) is likely, how are they synchronised?
5) If this involves communicating with each other, what medium is used
and how are delays handled (a la NTP pings)?
6) If all the clocks are synchronised in one place and then
transported all over the World, how is the Einstein affect of time
dilation handled due to the clocks changing in flight?

Now the interesting ones (for me anyway).

7) Where are the clock(s) located which provide the time for the GPS satellites?
8) If they are actually in the satellites, how are they all kept
synchronised with each other and the "master grandfather clock" on the
ground?
9) Are the satellites in geostationary orbit?
10) If they are geostationary, or move in relation to the ground, how
are the affects of the Einstein time dilation handled as they may be
travelling at a different speed than a point on the surface of the
Earth?
11) Extrapolating this, a point on the Equator would be moving faster
that a point at the poles or even Greenwich, for that matter. So would
a clock at each location move out of synchronisation with each other?

Aren't you glad I'm back :) BTW, where is /tvb these days, I haven't
seen any postings by him while I have catching up?

73
Steve - ZL3TUV
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From sar10538 at gmail.com  Thu Oct 30 12:51:42 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Fri, 31 Oct 2008 01:51:42 +1300
Subject: [time-nuts] Time-zones and World time..
In-Reply-To: <4909A498.6020005@tiscali.co.uk>
References: <1231b6a80810300453h117e2ef6o929e23f40c3ed236@mail.gmail.com>
	<4909A498.6020005@tiscali.co.uk>
Message-ID: <1231b6a80810300551q21b49efenf04a22fef1bf6145@mail.gmail.com>

2008/10/31 David Ackrill <dave.g0dja at tiscali.co.uk>:
> I would say it's very unlikely to happen.  People tend to prefer the
> time in their area to match up with the day.  So, having the sun come up
> at 7pm wouldn't suit a lot of people.

But people would get used to it after a while, maybe a generation, and
whose to say that the sun should come up at 7am, it's really just an
arbitrary concept.

> Recently the islanders on Jersey rejected a proposal to move to Central
> European Time (CET) see
> http://www.timeanddate.com/news/time/jersey-time-zone-referendum.html

I guess that is because we put the important decisions in the hands of voters :)

73
Steve - ZL3TUV
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From jdb at lartmaker.nl  Thu Oct 30 11:55:05 2008
From: jdb at lartmaker.nl (J.D. Bakker)
Date: Thu, 30 Oct 2008 13:55:05 +0200
Subject: [time-nuts] What's the time Mr Wolf...
In-Reply-To: <1231b6a80810300546s72af8bffu9892113782bd7b2@mail.gmail.com>
References: <1231b6a80810300546s72af8bffu9892113782bd7b2@mail.gmail.com>
Message-ID: <p062405a7c52f5000bc31@[130.161.115.44]>

At 01:46 +1300 31-10-2008, Steve Rooke wrote:
>                               I could Google for this but I'll get a
>quicker answer here

To me that reads as "My time is more valuable than yours".

Not to pick on you in particular, but I see this attitude a lot 
lately in fora, support groups and mailing lists. From your list it 
does look like most questions could indeed be answered by a few 
minutes of Googling, though.

JDB.
[apologies if you feel I snipped too much context, but this phrase in 
particular hit a nerve]
-- 
LART. 250 MIPS under one Watt. Free hardware design files.
http://www.lartmaker.nl/


From sar10538 at gmail.com  Thu Oct 30 13:09:00 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Fri, 31 Oct 2008 02:09:00 +1300
Subject: [time-nuts] What's the time Mr Wolf...
In-Reply-To: <p062405a7c52f5000bc31@130.161.115.44>
References: <1231b6a80810300546s72af8bffu9892113782bd7b2@mail.gmail.com>
	<p062405a7c52f5000bc31@130.161.115.44>
Message-ID: <1231b6a80810300609i61825394qa4d2ef57b2321bc7@mail.gmail.com>

My apologies to the list, it was unthoughtful of me. This was not my
intent, what I really meant was it's not always easy to formulate a
phrase to trigger the answer required out of Google and which sources
should I go to or believe. Really this was more meant to be a
compliment to the contributors of this list.

73
Steve - ZL3TUV

2008/10/31 J.D. Bakker <jdb at lartmaker.nl>:
> At 01:46 +1300 31-10-2008, Steve Rooke wrote:
>>                               I could Google for this but I'll get a
>>quicker answer here
>
> To me that reads as "My time is more valuable than yours".
>
> Not to pick on you in particular, but I see this attitude a lot
> lately in fora, support groups and mailing lists. From your list it
> does look like most questions could indeed be answered by a few
> minutes of Googling, though.
>
> JDB.
> [apologies if you feel I snipped too much context, but this phrase in
> particular hit a nerve]
> --
> LART. 250 MIPS under one Watt. Free hardware design files.
> http://www.lartmaker.nl/
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>



-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From jdb at lartmaker.nl  Thu Oct 30 12:22:13 2008
From: jdb at lartmaker.nl (J.D. Bakker)
Date: Thu, 30 Oct 2008 14:22:13 +0200
Subject: [time-nuts] What's the time Mr Wolf...
In-Reply-To: <1231b6a80810300609i61825394qa4d2ef57b2321bc7@mail.gmail.com>
References: <1231b6a80810300546s72af8bffu9892113782bd7b2@mail.gmail.com>
	<p062405a7c52f5000bc31@130.161.115.44>
	<1231b6a80810300609i61825394qa4d2ef57b2321bc7@mail.gmail.com>
Message-ID: <p062405aac52f564233a2@[130.161.115.44]>

At 02:09 +1300 31-10-2008, Steve Rooke wrote:
>                                 it's not always easy to formulate a
>phrase to trigger the answer required out of Google and which sources
>should I go to or believe.

Fair enough. For your first six questions, I'd use keywords including 
"nist" and "time", and start following links from there. For the GPS 
stuff handy keywords include "navstar", "usno" and "gpsworld".

Good luck,

JDB.
[from a somewhat different (sub)culture, but this may be useful too: 
http://www.catb.org/~esr/faqs/smart-questions.html ]
-- 
LART. 250 MIPS under one Watt. Free hardware design files.
http://www.lartmaker.nl/


From cfharris at erols.com  Thu Oct 30 13:42:40 2008
From: cfharris at erols.com (Chuck Harris)
Date: Thu, 30 Oct 2008 09:42:40 -0400
Subject: [time-nuts] Time-zones and World time..
In-Reply-To: <1231b6a80810300453h117e2ef6o929e23f40c3ed236@mail.gmail.com>
References: <1231b6a80810300453h117e2ef6o929e23f40c3ed236@mail.gmail.com>
Message-ID: <4909B9D0.8050708@erols.com>

With the great ease of computers to make the transformations,
there really isn't any point in removing local timezones.  It
is just a table after all... it is nothing like the old days when
every major town used Local Sidereal Time (eg. 12:00 is when the
sun is at its highest).  That caused major problems for the
railroads.

The biggest problem with local timezones is all of the continuously
changing variations on Daylight Savings Time.  That accounts for
the majority of the changes in the unix tz functions.

It was recently reported that the onset of DST coincides with an
increase in heart attacks, and the return to standard time coincides
with a decrease in heart attacks.  Yet another reason to ditch
Daylight Savings Time.

-Chuck Harris

Steve Rooke wrote:
> Hi,
> 
> I've been under the radar for a while so have not been able to keep up
> with the threads I was contributing to but that has been done to death
> and I will drop them. I've been very interested in reading peoplels
> thoughts on time-zones. Has there been any moves to adopt a common
> time for all countries in the world so as to alleviate the
> difficulties in dealing with time-zones?" I know there was the idea of
> Internet-time going around some time ago but I think that seems to
> have died a death. Thinking about it, what's the problem of adapting
> to daily life which is shifted by some number of hours off the clock.
> If we all used UTC everyone around the world would know when a certain
> time was in their own day. In my case for New Zealand, +12 hours would
> probably be adopted for the country, so AM becomes PM and I'd get up
> at 7PM (still that's not much different from now :) instead of AM.
> 
> I guess the question is, what's the likely-hood of a world standard
> time being adopted (sort of like Star Trek)?
> 
> 73
> Steve - ZL3TUV


From bruce.griffiths at xtra.co.nz  Thu Oct 30 14:01:10 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Fri, 31 Oct 2008 03:01:10 +1300
Subject: [time-nuts] Time-zones and World time..
In-Reply-To: <4909B9D0.8050708@erols.com>
References: <1231b6a80810300453h117e2ef6o929e23f40c3ed236@mail.gmail.com>
	<4909B9D0.8050708@erols.com>
Message-ID: <4909BE26.3090301@xtra.co.nz>

Chuck Harris wrote:
> With the great ease of computers to make the transformations,
> there really isn't any point in removing local timezones.  It
> is just a table after all... it is nothing like the old days when
> every major town used Local Sidereal Time (eg. 12:00 is when the
> sun is at its highest).  That caused major problems for the
> railroads.
>
> The biggest problem with local timezones is all of the continuously
> changing variations on Daylight Savings Time.  That accounts for
> the majority of the changes in the unix tz functions.
>
> It was recently reported that the onset of DST coincides with an
> increase in heart attacks, and the return to standard time coincides
> with a decrease in heart attacks.  Yet another reason to ditch
> Daylight Savings Time.
>
> -Chuck Harris
>
>   
Such "effects" are somewhat suspect as there is unlikely to have been
any comparable control group not subject to DST.
Also disentangling seasonal effects from possible DST related effects is
somewhat problematic.

Bruce


From tvb at LeapSecond.com  Thu Oct 30 14:36:36 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Thu, 30 Oct 2008 07:36:36 -0700
Subject: [time-nuts] What's the time Mr Wolf...
References: <1231b6a80810300546s72af8bffu9892113782bd7b2@mail.gmail.com>
Message-ID: <002a01c93a9c$ee3f12f0$0300a8c0@pc52>

> Hi,
> 
> This may have already been covered in this group so please excuse me
> for not combing the archives. I could Google for this but I'll get a
> quicker answer here and I know it will be the correct one.
> 
> !) Who decides on what is the correct time?

BIPM, the same guys that keeps the meter and the kilogram, etc.

> 2) Is the time standard stored on one master grandfather clock?

No.

> 3) As (2) is unlikely, if a number of clocks are involved, are they in
> different countries?

About 350 clocks in 50 countries, last I heard.

> 4) As (3) is likely, how are they synchronised?

They aren't synchronized in the traditional sense. But they are
slowly steered toward the mean. Each country has their own
official time but all follow the same mean time scale (UTC).

> 5) If this involves communicating with each other, what medium is used
> and how are delays handled (a la NTP pings)?

NTP is not used. Instead the clocks are compared using special
GPS receivers, or dedicated round-trip satellite links. Relativistic
and Sagnac corrections are applied as necessary.

> 6) If all the clocks are synchronised in one place and then
> transported all over the World, how is the Einstein affect of time
> dilation handled due to the clocks changing in flight?

The clocks typically aren't moved; they stay in their laboratories.
But when clocks are transported, yes, relativistic effects are
calculated and corrections applied.

> 
> Now the interesting ones (for me anyway).
> 
> 7) Where are the clock(s) located which provide the time for the GPS satellites?

USNO, in Washington DC.

> 8) If they are actually in the satellites, how are they all kept
> synchronised with each other and the "master grandfather clock" on the
> ground?

Yes, there are clocks in the satellites too. Their phase and rate
can be updated by ground control.

> 9) Are the satellites in geostationary orbit?

No.

> 10) If they are geostationary, or move in relation to the ground, how
> are the affects of the Einstein time dilation handled as they may be
> travelling at a different speed than a point on the surface of the
> Earth?

Geostationary or not, there are satellite relativistic effects which
are taken into account.

> 11) Extrapolating this, a point on the Equator would be moving faster
> that a point at the poles or even Greenwich, for that matter. So would
> a clock at each location move out of synchronisation with each other?

Yes, and this also is taken into account. When you get down
to measuring absolute frequency at 1e-14 and 1e-15 levels one
always takes the local gravitational field into account, which is
mostly a function of altitude, but also latitude.

> Aren't you glad I'm back :) BTW, where is /tvb these days, I haven't
> seen any postings by him while I have catching up?
> 
> 73
> Steve - ZL3TUV
> -- 
> Steve Rooke - ZL3TUV & G8KVD
> Omnium finis imminet

/tvb



From cfharris at erols.com  Thu Oct 30 14:52:24 2008
From: cfharris at erols.com (Chuck Harris)
Date: Thu, 30 Oct 2008 10:52:24 -0400
Subject: [time-nuts] Time-zones and World time..
In-Reply-To: <4909BE26.3090301@xtra.co.nz>
References: <1231b6a80810300453h117e2ef6o929e23f40c3ed236@mail.gmail.com>	<4909B9D0.8050708@erols.com>
	<4909BE26.3090301@xtra.co.nz>
Message-ID: <4909CA28.40707@erols.com>

Bruce Griffiths wrote:
> Chuck Harris wrote:

...

>>
>> It was recently reported that the onset of DST coincides with an
>> increase in heart attacks, and the return to standard time coincides
>> with a decrease in heart attacks.  Yet another reason to ditch
>> Daylight Savings Time.
>>
>> -Chuck Harris
>>
>>   
> Such "effects" are somewhat suspect as there is unlikely to have been
> any comparable control group not subject to DST.
> Also disentangling seasonal effects from possible DST related effects is
> somewhat problematic.

Correlation not being equal to causation always causes some lay folk
problems.  Though no one said that the DST shift caused the increase;
it would be interesting to know if when the US changed its DST dates,
the effect followed the change.

-Chuck Harris


From normn3ykf at stny.rr.com  Thu Oct 30 14:58:15 2008
From: normn3ykf at stny.rr.com (Norman J McSweyn)
Date: Thu, 30 Oct 2008 10:58:15 -0400
Subject: [time-nuts] labview, gpib, gps ,
	logging data and lost data points!!
In-Reply-To: <2F5D1A1EAD16449A85D430A9C7FC3D41@athlon>
References: <2F5D1A1EAD16449A85D430A9C7FC3D41@athlon>
Message-ID: <4909CB87.10807@stny.rr.com>

Ulrich,
I'll give ezgpib a try! Unfortunately it won't be until Feb. My vacation 
is coming to an end. Have about 15 or 20 more hours budgeted to play 
with my toys.

Have fixed the dropped data points, however. Used a timed sequence 
structure inside a for loop. The sequence structure has two frames. The 
first is the gpib routine. When that completes, Moto gps routine runs. 
Does it all in less than a second!!! How's that for precise timing? :-)

The way the gps routine is set up, I'm polling the board, rather than 
setting it up to output every second. The m12+t user's guide says the 
buffer on the gps board is read every second. How is that true if I poll 
the board and get a response in 200ms?

I'm presently polling the @@Hn. Think I'll add @@Gb and parse that. 
It'll give me the time stamp from the moto board. That along with the 
time stamp from the pc ought to get me more troubleshooting data at least.

BTW: I'm flushing the serial buffer prior to reading it, so the data is 
in response to my query, rather than being data that is in response to 
the previous poll.

tnx es 73 de Norm n3ykf


From brooke at pacific.net  Thu Oct 30 14:59:50 2008
From: brooke at pacific.net (Brooke Clarke)
Date: Thu, 30 Oct 2008 07:59:50 -0700
Subject: [time-nuts] Time-zones and World time..
In-Reply-To: <4909CA28.40707@erols.com>
References: <1231b6a80810300453h117e2ef6o929e23f40c3ed236@mail.gmail.com>	<4909B9D0.8050708@erols.com>	<4909BE26.3090301@xtra.co.nz>
	<4909CA28.40707@erols.com>
Message-ID: <4909CBE6.4030201@pacific.net>

Hi Chuck:

Not all of the U.S. uses DST, so there's a control group.

Have Fun,

Brooke Clarke
http://www.prc68.com/P/Prod.html  Products I make and sell
http://www.prc68.com/Alpha.shtml  All my web pages listed based on html name
http://www.PRC68.com
http://www.precisionclock.com
http://www.prc68.com/I/WebCam2.shtml 24/7 Sky-Weather-Astronomy Web Cam

Chuck Harris wrote:
> Bruce Griffiths wrote:
>> Chuck Harris wrote:
> 
> ...
> 
>>> It was recently reported that the onset of DST coincides with an
>>> increase in heart attacks, and the return to standard time coincides
>>> with a decrease in heart attacks.  Yet another reason to ditch
>>> Daylight Savings Time.
>>>
>>> -Chuck Harris
>>>
>>>   
>> Such "effects" are somewhat suspect as there is unlikely to have been
>> any comparable control group not subject to DST.
>> Also disentangling seasonal effects from possible DST related effects is
>> somewhat problematic.
> 
> Correlation not being equal to causation always causes some lay folk
> problems.  Though no one said that the DST shift caused the increase;
> it would be interesting to know if when the US changed its DST dates,
> the effect followed the change.
> 
> -Chuck Harris
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 


From mctylr at gmail.com  Thu Oct 30 15:25:08 2008
From: mctylr at gmail.com (michael taylor)
Date: Thu, 30 Oct 2008 11:25:08 -0400
Subject: [time-nuts] What's the time Mr Wolf...
In-Reply-To: <1231b6a80810300546s72af8bffu9892113782bd7b2@mail.gmail.com>
References: <1231b6a80810300546s72af8bffu9892113782bd7b2@mail.gmail.com>
Message-ID: <25630a120810300825n55169f79mc4e44f845526f902@mail.gmail.com>

On Thu, Oct 30, 2008 at 8:46 AM, Steve Rooke <sar10538 at gmail.com> wrote:
> Hi,
>
> This may have already been covered in this group so please excuse me
> for not combing the archives. I could Google for this but I'll get a
> quicker answer here and I know it will be the correct one.

I think it was approximately a year ago in the archives that there was
a good thread of suggested (mostly online) readings.

As well, an affordable and highly readable book is _Splitting the
Second : The Story of Atomic Time_ by Tony Jones, ISBN-13:
978-0750306409. Highly recommended, and I think it covers nearly all
of your questions.

-Michael


From cfharris at erols.com  Thu Oct 30 15:36:44 2008
From: cfharris at erols.com (Chuck Harris)
Date: Thu, 30 Oct 2008 11:36:44 -0400
Subject: [time-nuts] Time-zones and World time..
In-Reply-To: <4909CBE6.4030201@pacific.net>
References: <1231b6a80810300453h117e2ef6o929e23f40c3ed236@mail.gmail.com>	<4909B9D0.8050708@erols.com>	<4909BE26.3090301@xtra.co.nz>	<4909CA28.40707@erols.com>
	<4909CBE6.4030201@pacific.net>
Message-ID: <4909D48C.4010809@erols.com>

Brooke Clarke wrote:
> Hi Chuck:
> 
> Not all of the U.S. uses DST, so there's a control group.

That's true, but it cannot be said that the areas that don't
use DST are equivalent to those that do in all respects that
might cause heart problems.

It is thought the change in sleep/wake patterns is what causes
the stress to the heart, so I would be most interested in what
happened to identical populations when the DST date changed.

Unfortunately, he study period was from 1987 through 2006, so
I believe it missed the shift in DST dates.

The Swedish researchers that did the study said the number of
heart attacks drops 5% for the 7 days after the US changes from
DST to standard time, and spikes on the Monday we go back to DST.

I expect that the daily risk will be found to shift with the
change in the DST date.

-Chuck Harris


From rdarlington at gmail.com  Thu Oct 30 15:52:32 2008
From: rdarlington at gmail.com (Robert Darlington)
Date: Thu, 30 Oct 2008 09:52:32 -0600
Subject: [time-nuts] Time-zones and World time..
In-Reply-To: <4909D48C.4010809@erols.com>
References: <1231b6a80810300453h117e2ef6o929e23f40c3ed236@mail.gmail.com>
	<4909B9D0.8050708@erols.com> <4909BE26.3090301@xtra.co.nz>
	<4909CA28.40707@erols.com> <4909CBE6.4030201@pacific.net>
	<4909D48C.4010809@erols.com>
Message-ID: <b3bd5fcb0810300852s68dd14b1g3c5879da3d80d416@mail.gmail.com>

Never mind it happens right before the holidays.  I'm stressed either way.

On Thu, Oct 30, 2008 at 9:36 AM, Chuck Harris <cfharris at erols.com> wrote:

> Brooke Clarke wrote:
> > Hi Chuck:
> >
> > Not all of the U.S. uses DST, so there's a control group.
>
> That's true, but it cannot be said that the areas that don't
> use DST are equivalent to those that do in all respects that
> might cause heart problems.
>
> It is thought the change in sleep/wake patterns is what causes
> the stress to the heart, so I would be most interested in what
> happened to identical populations when the DST date changed.
>
> Unfortunately, he study period was from 1987 through 2006, so
> I believe it missed the shift in DST dates.
>
> The Swedish researchers that did the study said the number of
> heart attacks drops 5% for the 7 days after the US changes from
> DST to standard time, and spikes on the Monday we go back to DST.
>
> I expect that the daily risk will be found to shift with the
> change in the DST date.
>
> -Chuck Harris
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>

From grant at ghengineering.co.uk  Thu Oct 30 17:41:58 2008
From: grant at ghengineering.co.uk (Grant Hodgson)
Date: Thu, 30 Oct 2008 17:41:58 +0000
Subject: [time-nuts] 53310A help
In-Reply-To: <mailman.36.1225381954.13535.time-nuts@febo.com>
References: <mailman.36.1225381954.13535.time-nuts@febo.com>
Message-ID: <20081030173813.M17515@ghengineering.co.uk>

Does anybody know how to use the signal source that comes with the HP 53310A
Modulation Domain Analyser?  The MDA is fine, but I don't have a manual for
the signal source, and there seems to be nothing coming out of it - and yes, I
checked the battery.  There's no mention of how to use the signal source in
the 53310A manual.

regards

Grant Hodgson




From dforbes at dakotacom.net  Thu Oct 30 17:45:56 2008
From: dforbes at dakotacom.net (David Forbes)
Date: Thu, 30 Oct 2008 10:45:56 -0700
Subject: [time-nuts] Time-zones and World time..
In-Reply-To: <4909B9D0.8050708@erols.com>
References: <1231b6a80810300453h117e2ef6o929e23f40c3ed236@mail.gmail.com>
	<4909B9D0.8050708@erols.com>
Message-ID: <a06240503c52fa2e45fb0@[192.168.0.24]>

At 9:42 AM -0400 10/30/08, Chuck Harris wrote:
>With the great ease of computers to make the transformations,
>there really isn't any point in removing local timezones.  It
>is just a table after all... it is nothing like the old days when
>every major town used Local Sidereal Time (eg. 12:00 is when the
>sun is at its highest).  That caused major problems for the
>railroads.
>
>-Chuck Harris

Chuck,

I don't think you meant to say sidereal time, which is based the 
stars, not the sun. There are 366.25 or so days in a sidereal year!

-- 

--David Forbes, Tucson, AZ
http://www.cathodecorner.com/


From david.partridge at dsl.pipex.com  Thu Oct 30 18:07:53 2008
From: david.partridge at dsl.pipex.com (David C. Partridge)
Date: Thu, 30 Oct 2008 18:07:53 -0000
Subject: [time-nuts] Measuring ADEV with a PM6681 or CNT-81
In-Reply-To: <D7B1B5F4F3F27A4CB073BF422331203F0DD78793B0@Exchange1.lawo.de>
References: <D7B1B5F4F3F27A4CB073BF422331203F0DD74643CD@Exchange1.lawo.de><E1KtXgE-00080i-7k@meow.febo.com>
	<D7B1B5F4F3F27A4CB073BF422331203F0DD78793B0@Exchange1.lawo.de>
Message-ID: <4E7DA872C67E40569F94AA61C0A6450E@APOLLO>

> Apart from a suitable divider

And I have one PCB left for my divider if that's of interest ... Price as
before GBP20 plus shipping (GBP12 outside UK) plus 5% Paypal tax!

PS has anyone had a chance to measure the phase noise from my divider yet -
I just don't have the tools to do it, and I know that a few of you suggested
you'd look at that after building it.

Cheers
Dave

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Heinzmann, Stefan (ALC NetworX GmbH)
Sent: 30 October 2008 11:42
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Measuring ADEV with a PM6681 or CNT-81



From sar10538 at gmail.com  Thu Oct 30 18:20:35 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Fri, 31 Oct 2008 07:20:35 +1300
Subject: [time-nuts] What's the time Mr Wolf...
In-Reply-To: <002a01c93a9c$ee3f12f0$0300a8c0@pc52>
References: <1231b6a80810300546s72af8bffu9892113782bd7b2@mail.gmail.com>
	<002a01c93a9c$ee3f12f0$0300a8c0@pc52>
Message-ID: <1231b6a80810301120q1d9865bew52d122f8ebb4f56d@mail.gmail.com>

Tom,

Have you received any of my recent PMs?

2008/10/31 Tom Van Baak <tvb at leapsecond.com>:
...
>
> /tvb
>

73
Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From sar10538 at gmail.com  Thu Oct 30 18:23:05 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Fri, 31 Oct 2008 07:23:05 +1300
Subject: [time-nuts] What's the time Mr Wolf...
In-Reply-To: <25630a120810300825n55169f79mc4e44f845526f902@mail.gmail.com>
References: <1231b6a80810300546s72af8bffu9892113782bd7b2@mail.gmail.com>
	<25630a120810300825n55169f79mc4e44f845526f902@mail.gmail.com>
Message-ID: <1231b6a80810301123p39c23e5ah63d135fbac11844e@mail.gmail.com>

2008/10/31 michael taylor <mctylr at gmail.com>:
>
> I think it was approximately a year ago in the archives that there was
> a good thread of suggested (mostly online) readings.
>
> As well, an affordable and highly readable book is _Splitting the
> Second : The Story of Atomic Time_ by Tony Jones, ISBN-13:
> 978-0750306409. Highly recommended, and I think it covers nearly all
> of your questions.

Thanks for the pointers Michael, I'll see if I can get hold of a copy
of the book via an inter-library loan.

73, Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From sar10538 at gmail.com  Thu Oct 30 18:41:18 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Fri, 31 Oct 2008 07:41:18 +1300
Subject: [time-nuts] What's the time Mr Wolf...
In-Reply-To: <002a01c93a9c$ee3f12f0$0300a8c0@pc52>
References: <1231b6a80810300546s72af8bffu9892113782bd7b2@mail.gmail.com>
	<002a01c93a9c$ee3f12f0$0300a8c0@pc52>
Message-ID: <1231b6a80810301141j70c5d1d4oa088e6827c8dccd@mail.gmail.com>

Thanks for the very informative reply Tom.

2008/10/31 Tom Van Baak <tvb at leapsecond.com>:
>
>> 11) Extrapolating this, a point on the Equator would be moving faster
>> that a point at the poles or even Greenwich, for that matter. So would
>> a clock at each location move out of synchronisation with each other?
>
> Yes, and this also is taken into account. When you get down
> to measuring absolute frequency at 1e-14 and 1e-15 levels one
> always takes the local gravitational field into account, which is
> mostly a function of altitude, but also latitude.

Guess I've been dumb here but this must mean that not only is time
affected by relativistic effects but also oscillators as well then.

If gravity affects frequency, can this effect be seen as a daily
change in the EFC voltage of a GPS locked standard as caused by the
Moon? Does this also affect the frequency of the atomic standards used
to measure time? All this must make the measuring of absolute
frequency to the high orders of accuracy quite complex.

73, Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From sar10538 at gmail.com  Thu Oct 30 18:44:01 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Fri, 31 Oct 2008 07:44:01 +1300
Subject: [time-nuts] What's the time Mr Wolf...
In-Reply-To: <p062405aac52f564233a2@130.161.115.44>
References: <1231b6a80810300546s72af8bffu9892113782bd7b2@mail.gmail.com>
	<p062405a7c52f5000bc31@130.161.115.44>
	<1231b6a80810300609i61825394qa4d2ef57b2321bc7@mail.gmail.com>
	<p062405aac52f564233a2@130.161.115.44>
Message-ID: <1231b6a80810301144q32bac545w4ea00af82ae30bf2@mail.gmail.com>

2008/10/31 J.D. Bakker <jdb at lartmaker.nl>:
> At 02:09 +1300 31-10-2008, Steve Rooke wrote:
>>                                 it's not always easy to formulate a
>>phrase to trigger the answer required out of Google and which sources
>>should I go to or believe.
>
> Fair enough. For your first six questions, I'd use keywords including
> "nist" and "time", and start following links from there. For the GPS
> stuff handy keywords include "navstar", "usno" and "gpsworld".

Thanks for your understanding and useful pointers, this is exactly
what I was referring to. If you don't know where to start, it's not
always easy to get to the goal.

> Good luck,

I'll need it..

73, Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From cfharris at erols.com  Thu Oct 30 18:49:01 2008
From: cfharris at erols.com (Chuck Harris)
Date: Thu, 30 Oct 2008 14:49:01 -0400
Subject: [time-nuts] Time-zones and World time..
In-Reply-To: <a06240503c52fa2e45fb0@[192.168.0.24]>
References: <1231b6a80810300453h117e2ef6o929e23f40c3ed236@mail.gmail.com>	<4909B9D0.8050708@erols.com>
	<a06240503c52fa2e45fb0@[192.168.0.24]>
Message-ID: <490A019D.2040907@erols.com>

David Forbes wrote:
> At 9:42 AM -0400 10/30/08, Chuck Harris wrote:
>> With the great ease of computers to make the transformations,
>> there really isn't any point in removing local timezones.  It
>> is just a table after all... it is nothing like the old days when
>> every major town used Local Sidereal Time (eg. 12:00 is when the
>> sun is at its highest).  That caused major problems for the
>> railroads.
>>
>> -Chuck Harris
> 
> Chuck,
> 
> I don't think you meant to say sidereal time, which is based the 
> stars, not the sun. There are 366.25 or so days in a sidereal year!
> 

Yes, you are right.  The term stuck in my head from an astronomy course
I took in the distant past.  About the only point in my life where I
studied all of the major time systems and how they inter-related...
Apparently without any great retention... sigh!

Local Solar Time is the LST I was thinking of... only, I guess 00:00:00
is high noon in LST.... Maybe Local Sundial Time?

-Chuck Harris


From tomknox at nist.gov  Thu Oct 30 18:53:42 2008
From: tomknox at nist.gov (tomknox at nist.gov)
Date: Thu, 30 Oct 2008 14:53:42 -0400
Subject: [time-nuts] What's the time Mr Wolf...
In-Reply-To: <1231b6a80810300546s72af8bffu9892113782bd7b2@mail.gmail.com>
References: <1231b6a80810300546s72af8bffu9892113782bd7b2@mail.gmail.com>
Message-ID: <20081030145342.130221ddvnv3ftme@webmail.nist.gov>

Hi Steve;
I think God decides the time the fun parts is watching humans try to  
sort it out.
Currently the World has accept a specific number of vibrations  
(9,192,631,770) of a Cesium-133 atom to define one second. For the USA  
the master clock F1 is in Colorado and although the GPS sat's are  
monitored in Colorado their onboard clocks are Checked and corrected  
from Texas.
Best Wishes;
Thomas Knox




Quoting "Steve Rooke" <sar10538 at gmail.com>:

> Hi,
>
> This may have already been covered in this group so please excuse me
> for not combing the archives. I could Google for this but I'll get a
> quicker answer here and I know it will be the correct one.
>
> !) Who decides on what is the correct time?
> 2) Is the time standard stored on one master grandfather clock?
> 3) As (2) is unlikely, if a number of clocks are involved, are they in
> different countries?
> 4) As (3) is likely, how are they synchronised?
> 5) If this involves communicating with each other, what medium is used
> and how are delays handled (a la NTP pings)?
> 6) If all the clocks are synchronised in one place and then
> transported all over the World, how is the Einstein affect of time
> dilation handled due to the clocks changing in flight?
>
> Now the interesting ones (for me anyway).
>
> 7) Where are the clock(s) located which provide the time for the GPS  
> satellites?
> 8) If they are actually in the satellites, how are they all kept
> synchronised with each other and the "master grandfather clock" on the
> ground?
> 9) Are the satellites in geostationary orbit?
> 10) If they are geostationary, or move in relation to the ground, how
> are the affects of the Einstein time dilation handled as they may be
> travelling at a different speed than a point on the surface of the
> Earth?
> 11) Extrapolating this, a point on the Equator would be moving faster
> that a point at the poles or even Greenwich, for that matter. So would
> a clock at each location move out of synchronisation with each other?
>
> Aren't you glad I'm back :) BTW, where is /tvb these days, I haven't
> seen any postings by him while I have catching up?
>
> 73
> Steve - ZL3TUV
> --
> Steve Rooke - ZL3TUV & G8KVD
> Omnium finis imminet
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>



From david.partridge at dsl.pipex.com  Thu Oct 30 18:56:27 2008
From: david.partridge at dsl.pipex.com (David C. Partridge)
Date: Thu, 30 Oct 2008 18:56:27 -0000
Subject: [time-nuts] Time-zones and World time..
In-Reply-To: <490A019D.2040907@erols.com>
References: <1231b6a80810300453h117e2ef6o929e23f40c3ed236@mail.gmail.com>	<4909B9D0.8050708@erols.com><a06240503c52fa2e45fb0@[192.168.0.24]>
	<490A019D.2040907@erols.com>
Message-ID: <F9AC9EF3EE3D4A8E8947F3B3BB2CF46B@APOLLO>

Local Solar Time noon would still be 12:00:00.

If I remember correctly, the one that has noon as 00:00:00 is Astronomical
time (e.g. GMAT).

Cheers
Dave
-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Chuck Harris
Sent: 30 October 2008 18:49
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] Time-zones and World time..

Local Solar Time is the LST I was thinking of... only, I guess 00:00:00 is
high noon in LST.... Maybe Local Sundial Time?

-Chuck Harris

_______________________________________________
time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.



From tvb at LeapSecond.com  Thu Oct 30 18:58:23 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Thu, 30 Oct 2008 11:58:23 -0700
Subject: [time-nuts] What's the time Mr Wolf...
References: <1231b6a80810300546s72af8bffu9892113782bd7b2@mail.gmail.com>
	<002a01c93a9c$ee3f12f0$0300a8c0@pc52>
	<1231b6a80810301141j70c5d1d4oa088e6827c8dccd@mail.gmail.com>
Message-ID: <000c01c93ac1$7bc30f90$0300a8c0@pc52>

> If gravity affects frequency, can this effect be seen as a daily
> change in the EFC voltage of a GPS locked standard as caused by the
> Moon? Does this also affect the frequency of the atomic standards used
> to measure time? All this must make the measuring of absolute
> frequency to the high orders of accuracy quite complex.

Yes, very complex. No, you won't see it in something like a
GPSDO. The effect you're talking about here is thousands
to millions of times less than what you can measure.

12 hour or diurnal effects in a GPSDO are very common, but
they are due to local temperature, GPS orbits, multipath, etc.

/tvb



From sar10538 at gmail.com  Thu Oct 30 19:01:45 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Fri, 31 Oct 2008 08:01:45 +1300
Subject: [time-nuts] Time-zones and World time..
In-Reply-To: <4909B9D0.8050708@erols.com>
References: <1231b6a80810300453h117e2ef6o929e23f40c3ed236@mail.gmail.com>
	<4909B9D0.8050708@erols.com>
Message-ID: <1231b6a80810301201x70634b43j4b7dd52a890648d4@mail.gmail.com>

2008/10/31 Chuck Harris <cfharris at erols.com>:
> With the great ease of computers to make the transformations,
> there really isn't any point in removing local timezones.  It
> is just a table after all... it is nothing like the old days when
> every major town used Local Sidereal Time (eg. 12:00 is when the
> sun is at its highest).  That caused major problems for the
> railroads.

This assumes we are talking about electronic systems and means of
communications, what I was really thinking about was how this affects
people's ability to easily understand communication between countries.
This is not only affected by the plethora of local time-zones but with
ever changing daylight savings times. I communicate with the UK daily
and we have just gone through a period from being 11 hours ahead, then
12 and now 13 hours ahead as the DST changes are different in each
country. When I communicate with the US, I have to work out which
time-zone the place I'm talking to is in and correct for that. It's
probably not so much of a problem for someone in America  as you get
used to the time-zone differences but this adds complexity for an
outsider. I just wondered if it would add global communications and
buisiness to have a single World standard.

> The biggest problem with local timezones is all of the continuously
> changing variations on Daylight Savings Time.  That accounts for
> the majority of the changes in the unix tz functions.

Not so hard under Unix as the tz updates are easy to pick up but
Windows can be a problem if updates are not turned on, IE. some
service packs can break an application but you still need things like
the tz updates.

> It was recently reported that the onset of DST coincides with an
> increase in heart attacks, and the return to standard time coincides
> with a decrease in heart attacks.  Yet another reason to ditch
> Daylight Savings Time.

Hmmm... death by DST, how would that go down in an inquest. So is the
Government responsible for these deaths or the population for voting
for it...

73, Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From cfharris at erols.com  Thu Oct 30 19:08:55 2008
From: cfharris at erols.com (Chuck Harris)
Date: Thu, 30 Oct 2008 15:08:55 -0400
Subject: [time-nuts] Time-zones and World time..
In-Reply-To: <F9AC9EF3EE3D4A8E8947F3B3BB2CF46B@APOLLO>
References: <1231b6a80810300453h117e2ef6o929e23f40c3ed236@mail.gmail.com>	<4909B9D0.8050708@erols.com><a06240503c52fa2e45fb0@[192.168.0.24]>	<490A019D.2040907@erols.com>
	<F9AC9EF3EE3D4A8E8947F3B3BB2CF46B@APOLLO>
Message-ID: <490A0647.5020208@erols.com>

As I recall, Local Solar Time is also known as Apparent Solar Time, and
is defined as when the sun reaches its highest point over some local
meridian of interest (town hall?).

That point in time is called 00:00:00... Which sort of makes sense because
you can directly observe high-noon, but midnight can only be estimated.

-Chuck Harris


David C. Partridge wrote:
> Local Solar Time noon would still be 12:00:00.
> 
> If I remember correctly, the one that has noon as 00:00:00 is Astronomical
> time (e.g. GMAT).
> 
> Cheers
> Dave
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
> Behalf Of Chuck Harris
> Sent: 30 October 2008 18:49
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Time-zones and World time..
> 
> Local Solar Time is the LST I was thinking of... only, I guess 00:00:00 is
> high noon in LST.... Maybe Local Sundial Time?
> 
> -Chuck Harris



From james.p.lux at jpl.nasa.gov  Thu Oct 30 19:17:07 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Thu, 30 Oct 2008 12:17:07 -0700
Subject: [time-nuts] Time-zones and World time..
In-Reply-To: <490A0647.5020208@erols.com>
References: <1231b6a80810300453h117e2ef6o929e23f40c3ed236@mail.gmail.com>
	<4909B9D0.8050708@erols.com><a06240503c52fa2e45fb0@[192.168.0.24]>
	<490A019D.2040907@erols.com>	<F9AC9EF3EE3D4A8E8947F3B3BB2CF46B@APOLLO>
	<490A0647.5020208@erols.com>
Message-ID: <ECE7A93BD093E1439C20020FBE87C47FEB55C2FFA7@ALTPHYEMBEVSP20.RES.AD.JPL>



> -----Original Message-----
> From: time-nuts-bounces at febo.com
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Chuck Harris
> Sent: Thursday, October 30, 2008 12:09 PM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] Time-zones and World time..
>
> As I recall, Local Solar Time is also known as Apparent Solar
> Time, and is defined as when the sun reaches its highest
> point over some local meridian of interest (town hall?).
>
> That point in time is called 00:00:00... Which sort of makes
> sense because you can directly observe high-noon, but
> midnight can only be estimated.
>
> -Chuck Harris
>
One can, of course, observe meridian passage for a variety of stars at night, and from that determine the time (given a calendar and the appropriate almanac data), so you could directly observe midnight.

Don't forget too, that solar noon varies quite a bit (minutes) from "mean solar time" over the year.  If you're navigating your ship with noon sun sights, this is pretty important.


From imp at bsdimp.com  Thu Oct 30 19:27:54 2008
From: imp at bsdimp.com (M. Warner Losh)
Date: Thu, 30 Oct 2008 13:27:54 -0600 (MDT)
Subject: [time-nuts] What's the time Mr Wolf...
In-Reply-To: <1231b6a80810301141j70c5d1d4oa088e6827c8dccd@mail.gmail.com>
References: <1231b6a80810300546s72af8bffu9892113782bd7b2@mail.gmail.com>
	<002a01c93a9c$ee3f12f0$0300a8c0@pc52>
	<1231b6a80810301141j70c5d1d4oa088e6827c8dccd@mail.gmail.com>
Message-ID: <20081030.132754.1467006883.imp@bsdimp.com>

In message: <1231b6a80810301141j70c5d1d4oa088e6827c8dccd at mail.gmail.com>
            "Steve Rooke" <sar10538 at gmail.com> writes:
: 2008/10/31 Tom Van Baak <tvb at leapsecond.com>:
: >
: >> 11) Extrapolating this, a point on the Equator would be moving faster
: >> that a point at the poles or even Greenwich, for that matter. So would
: >> a clock at each location move out of synchronisation with each other?
: >
: > Yes, and this also is taken into account. When you get down
: > to measuring absolute frequency at 1e-14 and 1e-15 levels one
: > always takes the local gravitational field into account, which is
: > mostly a function of altitude, but also latitude.
: 
: Guess I've been dumb here but this must mean that not only is time
: affected by relativistic effects but also oscillators as well then.

Yes.  Oscillators will still resonate in their frame of reference at
their normal rate.  If that frame of reference is slightly different
than the defined standard frame of reference, then you need to take
that into account when you are comparing frequency data with others in
a two-way time exchange.  The objective is to tick at the same rate as
the standard frame, when the standard frame is measured from your
frame of reference...

: If gravity affects frequency, can this effect be seen as a daily
: change in the EFC voltage of a GPS locked standard as caused by the
: Moon? Does this also affect the frequency of the atomic standards used
: to measure time? All this must make the measuring of absolute
: frequency to the high orders of accuracy quite complex.

Gravity affects time.  The problem devolves into the classic case of
trying to keep things in sync between different frames of reference.

The tidal effects are much smaller than those from position.  I don't
think that these effects are visible at the 10-14 or 10-15 level, but
since I don't know what level they are visible at, I can't be sure.
I'm sure that someone on this list, maybe as part of their PhD thesis,
has measured this and can report it :-)

Warner


From tvb at LeapSecond.com  Thu Oct 30 20:08:19 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Thu, 30 Oct 2008 13:08:19 -0700
Subject: [time-nuts] What's the time Mr Wolf...
References: <1231b6a80810300546s72af8bffu9892113782bd7b2@mail.gmail.com><002a01c93a9c$ee3f12f0$0300a8c0@pc52><1231b6a80810301141j70c5d1d4oa088e6827c8dccd@mail.gmail.com>
	<20081030.132754.1467006883.imp@bsdimp.com>
Message-ID: <001001c93acb$40d8ec60$0300a8c0@pc52>

> The tidal effects are much smaller than those from position.  I don't
> think that these effects are visible at the 10-14 or 10-15 level, but
> since I don't know what level they are visible at, I can't be sure.
> I'm sure that someone on this list, maybe as part of their PhD thesis,
> has measured this and can report it :-)
> 
> Warner

Gravitational effects on frequency near the earth are on
the order of 1e-16 per meter of elevation. This level is too
small to measure directly, but if you separate clocks by
say, 1 km, the frequency shift is now 1e-13, which is very
measurable. Since no national timing labs are actually at
mean sea level they all take altitude into account in their
primary standards.

Tidal effects (so-called earth tides) are a couple of ten cm
over 6 hours and thus down in the 1e-17 range. No one has
seen these effects on atomic clocks yet. First, it's just too
small to be measured, even with the best optical clocks, but
second, the nearby reference clock that you use would also
experience the same pull (!) and thus a relative comparison
would reveal nothing.

/tvb



From james.p.lux at jpl.nasa.gov  Thu Oct 30 21:07:15 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Thu, 30 Oct 2008 14:07:15 -0700
Subject: [time-nuts] What's the time Mr Wolf...
In-Reply-To: <20081030.132754.1467006883.imp@bsdimp.com>
References: <1231b6a80810300546s72af8bffu9892113782bd7b2@mail.gmail.com>
	<002a01c93a9c$ee3f12f0$0300a8c0@pc52>
	<1231b6a80810301141j70c5d1d4oa088e6827c8dccd@mail.gmail.com>
	<20081030.132754.1467006883.imp@bsdimp.com>
Message-ID: <ECE7A93BD093E1439C20020FBE87C47FEB55C2FFBE@ALTPHYEMBEVSP20.RES.AD.JPL>

As I recall, the lunar gravity force is on the order of a few ppm of "g" (and I assume solar force is comparable).

So, the period of a pendulum does vary according to the time of day and phase of moon. (about a ppm or so)

I seem to recall that acceleration sensitivity of a crystals is on the order of a ppb/g, so the effect on a XO of the moon is down in the 1E-15 range..


Jim

> -----Original Message-----
> From: time-nuts-bounces at febo.com
> [mailto:time-nuts-bounces at febo.com] On Behalf Of M. Warner Losh
> Sent: Thursday, October 30, 2008 12:28 PM
> To: time-nuts at febo.com; sar10538 at gmail.com
> Subject: Re: [time-nuts] What's the time Mr Wolf...
>
> In message:
> <1231b6a80810301141j70c5d1d4oa088e6827c8dccd at mail.gmail.com>
>             "Steve Rooke" <sar10538 at gmail.com> writes:
> : 2008/10/31 Tom Van Baak <tvb at leapsecond.com>:
> : >
> : >> 11) Extrapolating this, a point on the Equator would be
> moving faster
> : >> that a point at the poles or even Greenwich, for that
> matter. So would
> : >> a clock at each location move out of synchronisation
> with each other?
> : >

> The tidal effects are much smaller than those from position.
> I don't think that these effects are visible at the 10-14 or
> 10-15 level, but since I don't know what level they are
> visible at, I can't be sure.
> I'm sure that someone on this list, maybe as part of their
> PhD thesis, has measured this and can report it :-)
>
> Warner
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com To unsubscribe,
> go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>


From henk at deriesp.demon.nl  Thu Oct 30 21:43:57 2008
From: henk at deriesp.demon.nl (Henk ten Pierick)
Date: Thu, 30 Oct 2008 22:43:57 +0100
Subject: [time-nuts] 53310A help
In-Reply-To: <20081030173813.M17515@ghengineering.co.uk>
References: <mailman.36.1225381954.13535.time-nuts@febo.com>
	<20081030173813.M17515@ghengineering.co.uk>
Message-ID: <38F353C3-0507-4C3A-893E-C83A5C0142D7@deriesp.demon.nl>

Hi,
1. connect as shown on the Quick Start Signal Source.
2. Signal source ON,
3. select Frequency Modulation,
4. press Autoscale.

This should give a sine on the display.
Does this work? If yes I will make a scan of the manual.
My Quick Start Signal Source is still alive.
How about your eprom?

regards,

Henk

On Oct 30, 2008, at 18:41, Grant Hodgson wrote:

> Does anybody know how to use the signal source that comes with the  
> HP 53310A
> Modulation Domain Analyser?  The MDA is fine, but I don't have a  
> manual for
> the signal source, and there seems to be nothing coming out of it -  
> and yes, I
> checked the battery.  There's no mention of how to use the signal  
> source in
> the 53310A manual.
>
> regards
>
> Grant Hodgson
>
>
>
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ 
> time-nuts
> and follow the instructions there.



From hmurray at megapathdsl.net  Thu Oct 30 23:34:43 2008
From: hmurray at megapathdsl.net (Hal Murray)
Date: Thu, 30 Oct 2008 16:34:43 -0700
Subject: [time-nuts] What's the time Mr Wolf...
In-Reply-To: Message from "Steve Rooke" <sar10538@gmail.com> of "Fri,
	31 Oct 2008 07:44:01 +1300."
	<1231b6a80810301144q32bac545w4ea00af82ae30bf2@mail.gmail.com> 
Message-ID: <20081030233444.20FF4BCD7@ip-64-139-1-69.sjc.megapath.net>


> Thanks for your understanding and useful pointers, this is exactly
> what I was referring to. If you don't know where to start, it's not
> always easy to get to the goal. 

This may not directly answer any of your questions, but it sure is a fun read.

    * Time Too Good to Be True, Daniel Kleppner
      Physics Today, March 2006, page 10

HTML version (needs cookies):
http://scitation.aip.org/error/cookies.jsp?url=http%3a//scitation.aip.org/jour
nals/doc/PHTOAD-ft/vol_59/iss_3/10_1.shtml

PDF version, needs new pdf reader:
  http://www.physicstoday.org/vol-59/iss-3/pdf/vol59no3p10_11.pdf

-- 
These are my opinions, not necessarily my employer's.  I hate spam.





From james.p.lux at jpl.nasa.gov  Thu Oct 30 23:51:53 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Thu, 30 Oct 2008 16:51:53 -0700
Subject: [time-nuts] What's the time Mr Wolf...
In-Reply-To: <20081030233444.20FF4BCD7@ip-64-139-1-69.sjc.megapath.net>
References: Message from "Steve Rooke" <sar10538@gmail.com> of "Fri,	31 Oct
	2008 07:44:01 +1300."
	<1231b6a80810301144q32bac545w4ea00af82ae30bf2@mail.gmail.com>
	<20081030233444.20FF4BCD7@ip-64-139-1-69.sjc.megapath.net>
Message-ID: <ECE7A93BD093E1439C20020FBE87C47FEB55C2FFDE@ALTPHYEMBEVSP20.RES.AD.JPL>


> -----Original Message-----
> From: time-nuts-bounces at febo.com
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Hal Murray
> Sent: Thursday, October 30, 2008 4:35 PM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] What's the time Mr Wolf...
>
>
> > Thanks for your understanding and useful pointers, this is exactly
> > what I was referring to. If you don't know where to start, it's not
> > always easy to get to the goal.
>
> This may not directly answer any of your questions, but it
> sure is a fun read.
>
>     * Time Too Good to Be True, Daniel Kleppner
>       Physics Today, March 2006, page 10
>

In the third column..

Not many years ago the possibility of merely detecting the minute effect of gravity on time was enough to inspire experimentalists. Over the years the accuracy of atomic clocks has become so high that the corrections for general relativity are not merely visible, they are so large that overlooking them in comparing the rates of atomic clocks in different laboratories2 or in the timing algorithms for the Global Positioning System3 (PHYSICS TODAY, May 2002, page 41) would cause catastrophes.

Hah... It's at the point where it's a viable science experiment for children in middle school (thank you Tom for doing this.. Now my daughters ask why we only have a GPSDO in the garage, and we don't have an atomic clock. )



From magnus at rubidium.dyndns.org  Thu Oct 30 23:52:42 2008
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Fri, 31 Oct 2008 00:52:42 +0100
Subject: [time-nuts] Time-zones and World time..
In-Reply-To: <1231b6a80810300453h117e2ef6o929e23f40c3ed236@mail.gmail.com>
References: <1231b6a80810300453h117e2ef6o929e23f40c3ed236@mail.gmail.com>
Message-ID: <490A48CA.9070008@rubidium.dyndns.org>

Steve Rooke wrote:
> Hi,
> 
> I've been under the radar for a while so have not been able to keep up
> with the threads I was contributing to but that has been done to death
> and I will drop them. I've been very interested in reading peoplels
> thoughts on time-zones. Has there been any moves to adopt a common
> time for all countries in the world so as to alleviate the
> difficulties in dealing with time-zones?" I know there was the idea of
> Internet-time going around some time ago but I think that seems to
> have died a death. Thinking about it, what's the problem of adapting
> to daily life which is shifted by some number of hours off the clock.
> If we all used UTC everyone around the world would know when a certain
> time was in their own day. In my case for New Zealand, +12 hours would
> probably be adopted for the country, so AM becomes PM and I'd get up
> at 7PM (still that's not much different from now :) instead of AM.

What's this AM and PM stuff got to do with it. You mean you would go up 
at 19 rather than 7?

> I guess the question is, what's the likely-hood of a world standard
> time being adopted (sort of like Star Trek)?

About zilch.

Cheers,
Magnus


From richiem at hughes.net  Thu Oct 30 23:55:49 2008
From: richiem at hughes.net (Richard Moore)
Date: Thu, 30 Oct 2008 16:55:49 -0700
Subject: [time-nuts] OFC (McCoy?)(Isotemp?) OCXO
Message-ID: <477DF250-4DD2-4CBF-82AE-50E98629B5AD@hughes.net>

Just received this OCXO from mr. fluke in China. Took exactly 14 days  
from time of order to get here to W. Washington. Hooked it up like  
the Isotemp 134 diagram. He said it would work, and it works perfectly.

The Isotemp spec EFC voltage range (positive slope) is 0 to the ref.  
voltage, in my set-up, +8.0V. On this OFC unit, I found no change in  
frequency until the EFC gets to about 1.28V. It reached 10 MHz, to  
within 1E-9,  at about 3.33V, with a total frequency span (1.28V to  
7.9V) of 10.6E-7, or very roughly 1.6E-7/V.  Unlike the Isotemp 134,  
this one has no trimming adjustment, so the only freq. control is via  
the EFC line, whose slope seems quite non-linear.

Output is a very clean sine wave, about 2.8Vp-p unloaded and 1.8Vp-p  
into 50 ohms.

This thing reaches temp fast and seems to be quite stable, but I  
won't have any reliable data until it is used in a more permanent way  
with stable supply voltages. Seems like a very nice unit.

Dick Moore


From magnus at rubidium.dyndns.org  Thu Oct 30 23:57:58 2008
From: magnus at rubidium.dyndns.org (Magnus Danielson)
Date: Fri, 31 Oct 2008 00:57:58 +0100
Subject: [time-nuts] Time-zones and World time..
In-Reply-To: <4909B9D0.8050708@erols.com>
References: <1231b6a80810300453h117e2ef6o929e23f40c3ed236@mail.gmail.com>
	<4909B9D0.8050708@erols.com>
Message-ID: <490A4A06.6030300@rubidium.dyndns.org>

Chuck Harris wrote:
> With the great ease of computers to make the transformations,
> there really isn't any point in removing local timezones.  It
> is just a table after all... it is nothing like the old days when
> every major town used Local Sidereal Time (eg. 12:00 is when the
> sun is at its highest).  That caused major problems for the
> railroads.

Which is the reason to coordinate it. Slightly off, but not too much for 
it to be a major obsticle.

> The biggest problem with local timezones is all of the continuously
> changing variations on Daylight Savings Time.  That accounts for
> the majority of the changes in the unix tz functions.

Having Daylight Saving Time as such is not as big issue as not having it 
coordinated between countries.

> It was recently reported that the onset of DST coincides with an
> increase in heart attacks, and the return to standard time coincides
> with a decrease in heart attacks.  Yet another reason to ditch
> Daylight Savings Time.

Interestingly enought, the decrease does not fully compensate the 
increase... so the net effect is an increase in heart attacks.

Cheers,
Magnus


From tvb at LeapSecond.com  Fri Oct 31 00:05:52 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Thu, 30 Oct 2008 17:05:52 -0700
Subject: [time-nuts] What's the time Mr Wolf...
References: <20081030233444.20FF4BCD7@ip-64-139-1-69.sjc.megapath.net>
Message-ID: <003d01c93aec$73b4a040$0300a8c0@pc52>

> This may not directly answer any of your questions, but it sure is a fun read.
> 
>    * Time Too Good to Be True, Daniel Kleppner
>      Physics Today, March 2006, page 10
> 
> HTML version (needs cookies):
> http://scitation.aip.org/error/cookies.jsp?url=http%3a//scitation.aip.org/jour
> nals/doc/PHTOAD-ft/vol_59/iss_3/10_1.shtml
> 
> PDF version, needs new pdf reader:
>  http://www.physicstoday.org/vol-59/iss-3/pdf/vol59no3p10_11.pdf

Hal, and James, see my follow-up to Kleppner's article...

<An Adventure in Relative Time-Keeping>
http://ptonline.aip.org/journals/doc/PHTOAD-ft/vol_60/iss_3/16_1.shtml
http://link.aip.org/link/PHTOAD/v60/i3/p16/s1/pdf

/tvb




From sar10538 at gmail.com  Fri Oct 31 00:20:43 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Fri, 31 Oct 2008 13:20:43 +1300
Subject: [time-nuts] What's the time Mr Wolf...
In-Reply-To: <20081030233444.20FF4BCD7@ip-64-139-1-69.sjc.megapath.net>
References: <sar10538@gmail.com>
	<1231b6a80810301144q32bac545w4ea00af82ae30bf2@mail.gmail.com>
	<20081030233444.20FF4BCD7@ip-64-139-1-69.sjc.megapath.net>
Message-ID: <1231b6a80810301720ic2ab052o8d91fa85ece2744c@mail.gmail.com>

2008/10/31 Hal Murray <hmurray at megapathdsl.net>:
>
> This may not directly answer any of your questions, but it sure is a fun read.
>
>    * Time Too Good to Be True, Daniel Kleppner
>      Physics Today, March 2006, page 10
>
> HTML version (needs cookies):
> http://scitation.aip.org/error/cookies.jsp?url=http%3a//scitation.aip.org/jour
> nals/doc/PHTOAD-ft/vol_59/iss_3/10_1.shtml
>
> PDF version, needs new pdf reader:
>  http://www.physicstoday.org/vol-59/iss-3/pdf/vol59no3p10_11.pdf
>

This makes an excellent and very entertaining read, thank you Hal. The
whole subject of time is very fascinating and far more interesting
than I ever thought before. Many thanks to all of you who have
enlightened me so much.

73, Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From sar10538 at gmail.com  Fri Oct 31 00:26:36 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Fri, 31 Oct 2008 13:26:36 +1300
Subject: [time-nuts] What's the time Mr Wolf...
In-Reply-To: <003d01c93aec$73b4a040$0300a8c0@pc52>
References: <20081030233444.20FF4BCD7@ip-64-139-1-69.sjc.megapath.net>
	<003d01c93aec$73b4a040$0300a8c0@pc52>
Message-ID: <1231b6a80810301726s74008144t253c634397b73826@mail.gmail.com>

2008/10/31 Tom Van Baak <tvb at leapsecond.com>:
>  http://www.physicstoday.org/vol-59/iss-3/pdf/vol59no3p10_11.pdf
>
> Hal, and James, see my follow-up to Kleppner's article...
>
> <An Adventure in Relative Time-Keeping>
> http://ptonline.aip.org/journals/doc/PHTOAD-ft/vol_60/iss_3/16_1.shtml
> http://link.aip.org/link/PHTOAD/v60/i3/p16/s1/pdf
>

Beautiful, just beautiful!

73, Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From sar10538 at gmail.com  Fri Oct 31 00:31:46 2008
From: sar10538 at gmail.com (Steve Rooke)
Date: Fri, 31 Oct 2008 13:31:46 +1300
Subject: [time-nuts] Time-zones and World time..
In-Reply-To: <490A48CA.9070008@rubidium.dyndns.org>
References: <1231b6a80810300453h117e2ef6o929e23f40c3ed236@mail.gmail.com>
	<490A48CA.9070008@rubidium.dyndns.org>
Message-ID: <1231b6a80810301731i638a0948u9a4b984023c222ed@mail.gmail.com>

2008/10/31 Magnus Danielson <magnus at rubidium.dyndns.org>:
>
> What's this AM and PM stuff got to do with it. You mean you would go up
> at 19 rather than 7?

Indeed it does mean that, and the 12 hour shift in time works for NZ
as compared to UTC because we are pretty close to 180 deg longitude
away from Greenwich. Sorry, if it was a clumsy piece of writing.

>> I guess the question is, what's the likely-hood of a world standard
>> time being adopted (sort of like Star Trek)?
>
> About zilch.

In the foreseeable future.

73, Steve
-- 
Steve Rooke - ZL3TUV & G8KVD
Omnium finis imminet


From SAIDJACK at aol.com  Fri Oct 31 00:48:43 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Thu, 30 Oct 2008 20:48:43 EDT
Subject: [time-nuts] beautiful jump
Message-ID: <d1e.374e280d.363bafeb@aol.com>

Hi guys,
 
there is a very nice Crystal jump visible online today:
 
   _http://resco.ucol.mx/Fury/gpsstat.htm_ 
(http://resco.ucol.mx/Fury/gpsstat.htm) 
 
Has anyone else seen a similar effect today?
 
This jump will be visible online for a couple more hours today.
 
While it looks very nice, these jumps are not what we want to see of  course.
 
bye,
Said



From james.p.lux at jpl.nasa.gov  Fri Oct 31 00:50:51 2008
From: james.p.lux at jpl.nasa.gov (Lux, James P)
Date: Thu, 30 Oct 2008 17:50:51 -0700
Subject: [time-nuts] What's the time Mr Wolf...
In-Reply-To: <003d01c93aec$73b4a040$0300a8c0@pc52>
References: <20081030233444.20FF4BCD7@ip-64-139-1-69.sjc.megapath.net>
	<003d01c93aec$73b4a040$0300a8c0@pc52>
Message-ID: <ECE7A93BD093E1439C20020FBE87C47FEB55C2FFE6@ALTPHYEMBEVSP20.RES.AD.JPL>


> -----Original Message-----
> From: time-nuts-bounces at febo.com
> [mailto:time-nuts-bounces at febo.com] On Behalf Of Tom Van Baak
> Sent: Thursday, October 30, 2008 5:06 PM
> To: Discussion of precise time and frequency measurement
> Subject: Re: [time-nuts] What's the time Mr Wolf...
>
> > This may not directly answer any of your questions, but it
> sure is a fun read.
> >
> >    * Time Too Good to Be True, Daniel Kleppner
> >      Physics Today, March 2006, page 10
> >
> > HTML version (needs cookies):
> >
> http://scitation.aip.org/error/cookies.jsp?url=http%3a//scitation.aip.
> > org/jour nals/doc/PHTOAD-ft/vol_59/iss_3/10_1.shtml
> >
> > PDF version, needs new pdf reader:
> >  http://www.physicstoday.org/vol-59/iss-3/pdf/vol59no3p10_11.pdf
>
> Hal, and James, see my follow-up to Kleppner's article...
>
> <An Adventure in Relative Time-Keeping>
> http://ptonline.aip.org/journals/doc/PHTOAD-ft/vol_60/iss_3/16_1.shtml
> http://link.aip.org/link/PHTOAD/v60/i3/p16/s1/pdf
>
Oh, you bet.. My daughters saw that (or more properly, your webpage about it), and that's when they started asking why WE couldn't do that.


From tvb at LeapSecond.com  Fri Oct 31 02:25:57 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Thu, 30 Oct 2008 19:25:57 -0700
Subject: [time-nuts] beautiful jump
References: <d1e.374e280d.363bafeb@aol.com>
Message-ID: <000201c93b00$06447bc0$0300a8c0@pc52>

> This jump will be visible online for a couple more hours today.
> 
> While it looks very nice, these jumps are not what we want to see of  course.

Said,

What environment is this GPSDO in? Is there any chance
that it is on a table or bench or rack shelf that got moved or
even slightly bumped at the time in question?

/tvb




From SAIDJACK at aol.com  Fri Oct 31 02:37:32 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Thu, 30 Oct 2008 22:37:32 EDT
Subject: [time-nuts] beautiful jump
Message-ID: <bc2.35ed39d2.363bc96c@aol.com>

Hi Tom,
 
that's possible, this particular unit has been jumping all along, even at  
night when no one is in the office. Usually it's not just one jump, but a series 
 of jumps. A mechanical bump would usually result in a disturbance, but not a 
 permanent change in the EFC voltage.
 
The unit is located in a remote sensing station in Mexico at the University  
of Colima.
 
bye,
Said
 
 
In a message dated 10/30/2008 19:26:46 Pacific Daylight Time,  
tvb at LeapSecond.com writes:


Said,

What environment is this GPSDO in? Is there any  chance
that it is on a table or bench or rack shelf that got moved  or
even slightly bumped at the time in  question?

/tvb




From tvb at LeapSecond.com  Fri Oct 31 02:54:57 2008
From: tvb at LeapSecond.com (Tom Van Baak)
Date: Thu, 30 Oct 2008 19:54:57 -0700
Subject: [time-nuts] beautiful jump
References: <bc2.35ed39d2.363bc96c@aol.com>
Message-ID: <002201c93b04$11f44960$0300a8c0@pc52>

OK, if no one was around that lessens the chance of vibration. Still, I didn't want to rule that possibility out. Some of my oscillators are very sensitive to any sort of shock. Even to the point of becoming crude seismometers.

I found with shock, they don't always return back to normal; i.e., it's a permanent change (a frequency jump) not a temporary glitch (like a phase jump). But I haven't studied this enough to know for sure. Has anyone else looked into the effects of vibration and shock on XO or OCXO?

Is yours an MTI 250-series OCXO?

/tvb

  ----- Original Message ----- 
  From: SAIDJACK at aol.com 
  To: tvb at leapsecond.com ; time-nuts at febo.com 
  Sent: Thursday, October 30, 2008 7:37 PM
  Subject: Re: [time-nuts] beautiful jump


  Hi Tom,

  that's possible, this particular unit has been jumping all along, even at night when no one is in the office. Usually it's not just one jump, but a series of jumps. A mechanical bump would usually result in a disturbance, but not a permanent change in the EFC voltage.

  The unit is located in a remote sensing station in Mexico at the University of Colima.

  bye,
  Said

  In a message dated 10/30/2008 19:26:46 Pacific Daylight Time, tvb at LeapSecond.com writes:

    Said,

    What environment is this GPSDO in? Is there any chance
    that it is on a table or bench or rack shelf that got moved or
    even slightly bumped at the time in question?

    /tvb


From SAIDJACK at aol.com  Fri Oct 31 04:05:37 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Fri, 31 Oct 2008 00:05:37 EDT
Subject: [time-nuts] beautiful jump
Message-ID: <be3.3144fab1.363bde11@aol.com>

Hi Tom,
 
that particular unit is a 270 MTI.
 
The jump was about 29ns before the loop pulled it back, this is a bit more  
than what I would expect on this OCXO with vibration induced noise.
 
The user has tried before to see if vibration is an issue, it was not some  
time ago.
 
bye,
Said
 
 
In a message dated 10/30/2008 19:55:42 Pacific Daylight Time,  
tvb at LeapSecond.com writes:

Is yours  an MTI 250-series  OCXO?

/tvb



From SAIDJACK at aol.com  Fri Oct 31 04:58:34 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Fri, 31 Oct 2008 00:58:34 EDT
Subject: [time-nuts] wavecrest available
Message-ID: <c68.3cc1f740.363bea7a@aol.com>

Hi guys,
 
fyi: a Wavecrest DTS-2077 is available from someone for $5 on Ebay.  That's 
the high-end unit with 1.3GHz range.
 
item: 120326604028
 
Seems they have a matching arm generator.
 
bye,
Said

From sam.mosel at baesystems.com  Fri Oct 31 05:49:02 2008
From: sam.mosel at baesystems.com (MOSEL Sam)
Date: Fri, 31 Oct 2008 16:49:02 +1100
Subject: [time-nuts] Time-zones and World time..
Message-ID: <200810310549.m9V5n2eH025161@sprint3.tenix.com>

 

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Steve Rooke

> When I communicate with the US, I have to work out which time-zone the
place I'm talking to
> is in and correct for that. It's probably not so much of a problem for
someone in America
> as you get used to the time-zone differences but this adds complexity
for an outsider.
> I just wondered if it would add global communications and buisiness to
have a single World standard.

When most people communicate with other time zones it's via telephone or
email, and when they calculate the destination local time, it's to
answer the question "Are they likely to be awake?" or "Are they more
likely to be at work or at home?". Having a global time won't solve this
problem, you will still have to do the conversion to find out the local
time to answer these questions.

If you're scheduling radio comms then the Military probably have the
correct approach - Zulu time for everything.

Sam.

Disclaimer :
The contents of this e-mail including any attachments are intended only
for the person or entity to which this e-mail is addressed.  If you are not,
or believe you may not be, the intended recipient, please advise the sender
immediately by return e-mail, delete this e-mail and destroy any copies.
The Company does not warrant nor guarantee that this email communication is free
from errors, virus, interception or interference.



From bill at iaxs.net  Fri Oct 31 07:28:43 2008
From: bill at iaxs.net (Bill Hawkins)
Date: Fri, 31 Oct 2008 02:28:43 -0500
Subject: [time-nuts] beautiful jump
In-Reply-To: <be3.3144fab1.363bde11@aol.com>
References: <be3.3144fab1.363bde11@aol.com>
Message-ID: <B330DE14DC004F6AA4C86811B68CA0D7@cyrus>

So, have you got a three-axis accelerometer that you can record?

Might want to record some radiation detectors, too.

There are ways to support boxes that greatly reduce tremors from
the Earth and those who move on its surface.

Bill Hawkins



From j.bastemeijer at tudelft.nl  Fri Oct 31 09:10:21 2008
From: j.bastemeijer at tudelft.nl (Jeroen Bastemeijer)
Date: Fri, 31 Oct 2008 10:10:21 +0100
Subject: [time-nuts] HP1600A manual
Message-ID: <490ACB7D.5090700@tudelft.nl>

Dear All,

Is there anyone out there who has a digital copy of the HP 1600A logic 
analyzer manual? I found such an old machine, and I'm wondering if it is 
still working...

There are manuals for sale for approx $50 (excl. shipping). However, the 
HP1600A seems not to be very responsive. So, investing $50 for a machine 
which is defective and probably cannot be repaired seems like a waste.

Or is there anyone who can give a hint on how to test a HP 1600A, to get 
a good indication if it is still functioning (reasonably) okay. At this 
moment the machine seems to be locked up. Allthough there is a nice 
pattern of 1's and 0's on the screen....

Thanks, best regards Jeroen
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From ernieperes at aol.com  Fri Oct 31 11:52:28 2008
From: ernieperes at aol.com (ernieperes at aol.com)
Date: Fri, 31 Oct 2008 07:52:28 -0400
Subject: [time-nuts] OFC (McCoy?)(Isotemp?) OCXO
In-Reply-To: <477DF250-4DD2-4CBF-82AE-50E98629B5AD@hughes.net>
References: <477DF250-4DD2-4CBF-82AE-50E98629B5AD@hughes.net>
Message-ID: <8CB09664845CD5F-19C-2AF8@webmail-da04.sysops.aol.com>

Hi Dick,

I also have the same OCXO   OFC  and tried in a Brook Shera circuit but 
I was not satisfied....
on the long run I could notice the day and night temp difference on the 
EFC scale and the phase plot also show
similar deviation...

Rgds Ernie.



-----Original Message-----
From: Richard Moore <richiem at hughes.net>
To: time-nuts at febo.com
Sent: Fri, 31 Oct 2008 12:55 am
Subject: [time-nuts] OFC (McCoy?)(Isotemp?) OCXO



Just received this OCXO from mr. fluke in China. Took exactly 14 days
from time of order to get here to W. Washington. Hooked it up like
the Isotemp 134 diagram. He said it would work, and it works perfectly.

The Isotemp spec EFC voltage range (positive slope) is 0 to the ref.
voltage, in my set-up, +8.0V. On this OFC unit, I found no change in
frequency until the EFC gets to about 1.28V. It reached 10 MHz, to
within 1E-9,  at about 3.33V, with a total frequency span (1.28V to
7.9V) of 10.6E-7, or very roughly 1.6E-7/V.  Unlike the Isotemp 134,
this one has no trimming adjustment, so the only freq. control is via
the EFC line, whose slope seems quite non-linear.

Output is a very clean sine wave, about 2.8Vp-p unloaded and 1.8Vp-p
into 50 ohms.

This thing reaches temp fast and seems to be quite stable, but I
won't have any reliable data until it is used in a more permanent way
with stable supply voltages. Seems like a very nice unit.

Dick Moore

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From iovane at inwind.it  Fri Oct 31 15:29:18 2008
From: iovane at inwind.it (iovane at inwind.it)
Date: Fri, 31 Oct 2008 16:29:18 +0100
Subject: [time-nuts] beautiful jump
Message-ID: <K9M0CU$C3AA1515ED3E117ACF57A3D8A3C3A1F2@libero.it>

On Oct 30 SAIDJACK wrote:

> Hi guys,
>  
> there is a very nice Crystal jump visible online today:
>  
>    _http://resco.ucol.mx/Fury/gpsstat.htm_ 
> (http://resco.ucol.mx/Fury/gpsstat.htm) 
>  
> Has anyone else seen a similar effect today?
>  
> This jump will be visible online for a couple more hours today.
>  
> While it looks very nice, these jumps are not what we want to see of  course.
>  
> bye,
> Said

Said,

this jump was beautiful, I had saved it.
But I feel you have lost the sister jump occurred on Oct 27, 
which was IMPRESSIVE. I've uploaded it for you and the list 
to:

http://xoomer.alice.it/iovane/colima.htm

The Oct 27 jump made me (to some extent) predict the Oct 30
jump, and the record is in what I posted to a friend of mine
who reads cc, on Oct 28. 

To quote:
"
look at this:
http://resco.ucol.mx/Fury/gpsstat.htm
and save only the graph.

It is a jump of a crystal. 
It could test my idea regarding possible effects of new 
moons, if a restoring jump occurs in the early hours of 
october 30.
The graph covers 24 hrs....
snip..
Please save the graph before this evening, as the scale will 
change before about 23:00 UT.
"

And the jump occurred.

Said and all,

do you think it is mere casuality?

University of Colima refused the new replacement unit you 
offered them (I believe for free). I think that there is some
reason........

Please let me know of any progress on this subject.
Regards,

Antonio I8IOV





From SAIDJACK at aol.com  Fri Oct 31 17:59:06 2008
From: SAIDJACK at aol.com (SAIDJACK at aol.com)
Date: Fri, 31 Oct 2008 13:59:06 EDT
Subject: [time-nuts] beautiful jump
Message-ID: <cd8.3ca64b57.363ca16a@aol.com>

Hi Antonio,
 
wow, that's amazing. Your prediction was pretty accurate!!
 
So I wonder if we have one of the most sensitive gravitational sensors out  
there :)
 
How did you correlate the jump to the new moon sequence? Did your units  jump 
accordingly?
 
>University of Colima refused the new replacement unit you  
>offered them (I believe for free). I think that there is  some
>reason........
 
Well, they said it was extremely difficult to get packages in and out of  
Mexico due to the customs, so they rather keep that unit since the jumps are  
generally less than 1ppb. We lost some packages that were sent to them. But  yes, 
maybe they are aware of the potential sensitivity to stellar  constellations??
 
bye,
Said
 
 
In a message dated 10/31/2008 08:30:06 Pacific Daylight Time,  
iovane at inwind.it writes:

http://xoomer.alice.it/iovane/colima.htm

The Oct 27 jump made me  (to some extent) predict the Oct 30
jump, and the record is in what I  posted to a friend of mine
who reads cc, on Oct 28.  



From fortime at bellsouth.net  Fri Oct 31 18:10:44 2008
From: fortime at bellsouth.net (phil)
Date: Fri, 31 Oct 2008 14:10:44 -0400
Subject: [time-nuts] beautiful jump
References: <cd8.3ca64b57.363ca16a@aol.com>
Message-ID: <000601c93b83$fed9c910$a001a8c0@officemail>


----- Original Message ----- 
From: <SAIDJACK at aol.com>
To: <time-nuts at febo.com>
Cc: <thomas at flyingkettle.com>
Sent: Friday, October 31, 2008 1:59 PM
Subject: Re: [time-nuts] beautiful jump


> Hi Antonio,
>
> wow, that's amazing. Your prediction was pretty accurate!!
>
> So I wonder if we have one of the most sensitive gravitational sensors out
> there :)
>
> How did you correlate the jump to the new moon sequence? Did your units 
> jump
> accordingly?
>
>>University of Colima refused the new replacement unit you
>>offered them (I believe for free). I think that there is  some
>>reason........
>
> Well, they said it was extremely difficult to get packages in and out of
> Mexico due to the customs, so they rather keep that unit since the jumps 
> are
> generally less than 1ppb. We lost some packages that were sent to them. 
> But  yes,
> maybe they are aware of the potential sensitivity to stellar 
> constellations??
>
> bye,
> Said
>

If the oscillator was placed inside a separate, locally created magnetic 
field, would that stop or lessen that jump?

Phil 



From gard at ucol.mx  Fri Oct 31 18:30:41 2008
From: gard at ucol.mx (Gabriel A. Reyes-Davila)
Date: Fri, 31 Oct 2008 18:30:41 +0000
Subject: [time-nuts] beautiful jump
In-Reply-To: <000601c93b83$fed9c910$a001a8c0@officemail>
References: <cd8.3ca64b57.363ca16a@aol.com>
	<000601c93b83$fed9c910$a001a8c0@officemail>
Message-ID: <490B4ED1.508@ucol.mx>

Hi all there. Here Gabriel Reyes form University of Colima.
The Fury is under almost ideal conditions in an isolated (from people) room.
Jumps ocurr at any time of the day, any day, aleatory.
No one single correlation with earthquakes. I manage a local seismic 
network and the
local earthquakes detected along the present year range form 2 to 5.5 
Ritcher.
Repeat again, no correlation.
Bye.
GR



From richiem at hughes.net  Fri Oct 31 20:01:07 2008
From: richiem at hughes.net (Richard Moore)
Date: Fri, 31 Oct 2008 13:01:07 -0700
Subject: [time-nuts] OFC OCXO
In-Reply-To: <mailman.1.1225454401.23733.time-nuts@febo.com>
References: <mailman.1.1225454401.23733.time-nuts@febo.com>
Message-ID: <C69A845F-C20A-4AAA-A5D5-858CB40117F6@hughes.net>

Hi Ernie -- thx for the feedback. I have had all of those effects and  
more with an HP10811A and an EG&G Cinox version of the 10811A, so I  
won't be surprised to see such things with this one either. I'm going  
to try it with Bert Zauhar's FLL controller to see how it runs. You  
can visit my experience to date at:
  www.moorepage.net/gps2.html

I'll update the site again after I run the OFC for a while.

Best,
Dick Moore

Original message
Message: 9
Date: Fri, 31 Oct 2008 07:52:28 -0400
From: ernieperes at aol.com
Subject: Re: [time-nuts] OFC (McCoy?)(Isotemp?) OCXO
To: time-nuts at febo.com
Message-ID: <8CB09664845CD5F-19C-2AF8 at webmail-da04.sysops.aol.com>
Content-Type: text/plain; charset="us-ascii"; format=flowed

Hi Dick,

I also have the same OCXO   OFC  and tried in a Brook Shera circuit but
I was not satisfied....
on the long run I could notice the day and night temp difference on the
EFC scale and the phase plot also show
similar deviation...

Rgds Ernie.


From bruce.griffiths at xtra.co.nz  Fri Oct 31 22:00:59 2008
From: bruce.griffiths at xtra.co.nz (Bruce Griffiths)
Date: Sat, 01 Nov 2008 11:00:59 +1300
Subject: [time-nuts] OFC OCXO
In-Reply-To: <C69A845F-C20A-4AAA-A5D5-858CB40117F6@hughes.net>
References: <mailman.1.1225454401.23733.time-nuts@febo.com>
	<C69A845F-C20A-4AAA-A5D5-858CB40117F6@hughes.net>
Message-ID: <490B801B.2060900@xtra.co.nz>

Richard Moore wrote:
> Hi Ernie -- thx for the feedback. I have had all of those effects and  
> more with an HP10811A and an EG&G Cinox version of the 10811A, so I  
> won't be surprised to see such things with this one either. I'm going  
> to try it with Bert Zauhar's FLL controller to see how it runs. You  
> can visit my experience to date at:
>   www.moorepage.net/gps2.html
>
> I'll update the site again after I run the OFC for a while.
>
> Best,
> Dick Moore
>   
Dick

The usual way of reducing charge injection transients from a DVM into
the circuit being measured is to use an RC low pass filter between the
circuit and THE DVM.
Charge injection can be somewhat larger for those autozeroing DVMs that
do not use a precharge amplifier to reduce the effect.
panel mount DVMs do not usually have a precharge amplifier.

With a low pass filter it may be possible to reduce the value of the 50K
isolation resistor that you used.
The value is relatively high because it relies on the DVM and wiring
capacitance as the capacitive part of the RC low pass filter.

Bruce


From cdelect at juno.com  Fri Oct 31 21:07:17 2008
From: cdelect at juno.com (Corby Dawson)
Date: Fri, 31 Oct 2008 14:07:17 -0700
Subject: [time-nuts] Efratom MRT schematic
Message-ID: <20081031.140717.3856.2.cdelect@juno.com>

Hi,

I'm working on an Efratom MRT rubidium standard and I need the power
supply schematic.

Everything is working OK except the battery charge circuit is not
working.

With good batteries you can pull the AC cord and it runs on the batteries
OK, but then when you plug the AC back in the charge current (with very
discharged batteries) is very low. The batteries charge fine if a bench
supply is used instead of the MRT supply.

Anyone have a copy of the manual or can supply the schematic of the power
supply and charger? 

Thanks,

Corby Dawson
____________________________________________________________
Criminal Lawyers - Click here.
http://thirdpartyoffers.juno.com/TGL2141/fc/Ioyw6i3oGdgUSMCXb8nALpcWDYwVWGvlod18EcSO0mdpEPQlyYZoHX/


From iovane at inwind.it  Fri Oct 31 23:40:25 2008
From: iovane at inwind.it (iovane at inwind.it)
Date: Sat,  1 Nov 2008 00:40:25 +0100
Subject: [time-nuts] beautiful jump
Message-ID: <K9MN3D$487F971C33A25A4EA0B931DEE35C2E0F@libero.it>

On Fri, 31 Oct 2008 13:59:06 EDT SAIDJACK wrote:

> Hi Antonio,
>  
> wow, that's amazing. Your prediction was pretty accurate!!
>  
> So I wonder if we have one of the most sensitive gravitational sensors out  
> there :)

You know that the issue is reproducibility. 

> How did you correlate the jump to the new moon sequence? Did your units  jump 
> accordingly?

Being dealing with unexplained phenomena that seem to occur 
during solar eclipses, and around new and maybe full moons, 
of apparently gravitational nature, and being investigating 
on the subject since 1999, I happened to see odd behaviours 
on stationary pendulums, besides eclipse days, in the epochs 
of new moons as well, say when the angular distance between 
sun and moon is less than 20 degrees. The observed phenomena would seem to be rather symmetrical relative to the time of 
new moon.

Along with this, I happened to record jumps in frequency of 
tuning forks, the last one having been recorded the day after 
the Aug 1 2008 solar eclipse. In this case I don't know if 
there has been a first jump the day before the eclipse, 
because I had problems recording. I have to say that not all 
the eclipses/new moons gave jumps.

I've just uploaded the best example here: 

http://xoomer.alice.it/iovane/forkjump.htm 

You see two opposite jumps around a full moon, the second 
one being smaller. A good analogy with what happened in Colima.

On the other hand, I have never observed jumps in my 
crystals, at the level of 0.1 ppb.

Unluckily I was not recording during last new moon.

The two recent Colima jumps seem to be consistent with my 
previous observations, and encouraging, the second one being 
important even from a statistical point of view. 
I hope that they will not replace the crystal.

Along with my friend Thomas Goodey ( http://www.allais.info ),
we are planning to do, besides his paraconical pendulum 
tests, specific crystal and tuning fork tests as well, at the 
occurrence of eclipses in the next years. In some cases we 
will reach the eclipse areas.

Antonio I8IOV