[time-nuts] time-nuts newbie

Chris Albertson albertson.chris at gmail.com
Thu May 2 17:43:45 EDT 2013


Turning off the Rb is a good idea.  That is one of the best features
of the Rb is that it will come back on from a zero power and be pretty
much spot on the frequency but the phase will be random.    So the
question is that if you want to re-calibrate the OCXO how long to you
need to compare it to the Rb.  You can't look at the phase difference,
that has been randomized by the power cycle.

I think one could get at least 10 and maybe 100 times better than the
OP's requirement and still be under the $500 limit.


On Thu, May 2, 2013 at 12:59 PM, Bob Camp <lists at rtty.us> wrote:
> Hi
>
> A clock based on an eBay Rb can be set up to pull less than 10 watts. Based
> on 8 hours of light a day that would get you to 30 watts of solar needed to
> power it. That's a pretty small fraction of your 480W setup.  You will get
> CSAC level timing and still fit your budget.
>
> For a lower power solution, wake up the Rb once a day around mid day. Only
> do it if the solar has surplus power. Re-sync your OCXO to the Rb. That
> should cut the power by a factor of about 10:1. A Google search for "RBXO"
> will turn up details on the process. Not quite CSAC performance, but far
> better than the OCXO alone.
>
> Bob
>
> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
> Behalf Of Timothy Bastian
> Sent: Thursday, May 02, 2013 12:36 PM
> To: time-nuts at febo.com
> Subject: Re: [time-nuts] time-nuts newbie
>
> Wow I didn't know how much I was going to stir up here.  As for the accuracy
> of the DS32khz you are correct in what the literature says. They call for an
> accuracy of one minute per year. The 10 seconds / year is what the gentleman
> who designed the clock thought would be possible. The testing he has done is
> giving better results than 10 seconds / year. My clock has not been running
> long enough to give you any meaningful results.
>
>
>  As far as the requirements for my chronometer... there is what I would like
> to have and what I can afford. A clock driven by a csac (SA.45s) would be
> the ultimate. I am however shooting for something in the $500.00 or
> less price range. I have ships power available to power the clock but would
> like to have the ability to run on an internal battery for an extended
> period if needed. Say for two months. I have 4, 120 watt solar panels with
> 500 amp hours of 12 volt battery power. I'm shooting for a size of not more
> than one cubic foot. You are correct about the 100 ppb aging, which I
> believe will put me at +/- 3 seconds / year. A GPS time reference to set the
> clock would be acceptable however the whole point of having said clock is to
> still be able to navigate in the event of GPS failure.
>
> Thanks for all of the replies,
>
>   Tim KK4FQB
>
> ________________________________
> From: "time-nuts-request at febo.com" <time-nuts-request at febo.com>
> To: time-nuts at febo.com
> Sent: Wednesday, May 1, 2013 11:08 AM
> Subject: time-nuts Digest, Vol 106, Issue 1
>
>
> 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
>     time-nuts-request at febo.com
>
> You can reach the person managing the list at
>     time-nuts-owner at febo.com
>
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of time-nuts digest..."
>
>
> Today's Topics:
>
>   1. Re: Time nut newbie (Rex)
>   2. Re: 10811 (John Miles)
>   3. Re: HP5065B !!! (Jim Palfreyman)
>   4. Re: Time nut newbie (Jim Palfreyman)
>   5. Re: Time nut newbie (Hal Murray)
>   6. Re: Time nut newbie (Chris Albertson)
>   7. Re: Time nut newbie (Attila Kinali)
>   8. Re: Time nut newbie (Bob Camp)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Tue, 30 Apr 2013 18:57:20 -0700
> From: Rex <rexa at sonic.net>
> To: Discussion of precise time and frequency measurement
>     <time-nuts at febo.com>
> Subject: Re: [time-nuts] Time nut newbie
> Message-ID: <51807680.2040705 at sonic.net>
> Content-Type: text/plain; charset=windows-1252; format=flowed
>
> It doesn't affect the general magnitude conclusions by Bruce, but as
> long as we are making corrections, my calculator seems to think
> 60 * 60 * 24 * 12 = 1036800 seconds in 12 days, not 1024800.  That does
> come out to 115.7 days for 1 sec error. Maybe the 12-day number was a typo?
>
> -Rex
>
>
> On 4/30/2013 12:57 PM, Bruce Griffiths wrote:
>> 12 days is 1024800 s ie just over 1 million seconds so a frequency
>> offset of 0.1ppm results in a time error of ~ 0.1s not 1s.
>> 1sec error would occur in just under 116 days,
>>
>> Bruce
>>
>> Bob Camp wrote:
>>> Hi
>>>
>>> If you take a look down in the fine print on the OCXO spec, the aging
>>> rate
>>> is 100 ppb / year in the first year. If you are off by 0.1 ppm (100 ppb)
>>> your clock will gain a second in less than 12 days.
>>>
>>> Bob
>>>
>
>
>
> ------------------------------
>
> Message: 2
> Date: Tue, 30 Apr 2013 19:53:49 -0700
> From: "John Miles" <jmiles at pop.net>
> To: "'Discussion of precise time and frequency measurement'"
>     <time-nuts at febo.com>
> Subject: Re: [time-nuts] 10811
> Message-ID: <004a01ce4617$1ba19710$52e4c530$@pop.net>
> Content-Type: text/plain;    charset="UTF-8"
>
>> Close, but it's for the 105, not the 5061, and the boards are physically
> very
>> different.
>
> The 5061A upgrade used those 105-series boards.  With the 5061B, they
> changed the part number of A1A3 (the OCXO interface board) from 00105-6044
> to 05061-6198, but I don't see any major differences in the schematic,
> looking at the Artek .PDF manual for the 5061B.
>
>> The part number on the connector for the board is the same as the
> connector
>> for the 10811. Does anyone know where to get boards that fit the
> connector?
>> Mouser carries the connector, but I can't find any boards.
>
> You don't really need a board -- I didn't use one (see
> http://www.ke5fx.com/tbolt.htm ).  It uses a pretty common edge connector
> that can be pulled off of any number of random surplus HP PCBs, if you don't
> want to order one.
>
>> how often do people need to retune the 10811? I have a pair of the 10811-
>> 60109's, another 10811, and a 10544 and all are within 1 Hz of 10 MHz.
> That's close
>> enough
>
> Some anecdata: my GPS-disciplined 10811-60109 has been running for about 5
> years without any retuning.  The DAC voltage is currently about 0.52V, and
> I'm sure I would have started it out near 0.0, so about 10% of its EFC
> control range has been needed after 5 years.  (Of course it could have
> wandered around arbitrarily in the meantime, but I doubt it.)
>
> At -0.324 Hz/volt, this would be about 0.03 Hz per year of positive drift on
> average, or 3E-9 per year.  That's in line with what I've seen other
> well-settled 10811s achieve.
>
>> Is there any advantage in using the 723 voltage regulator? The 10811 and
>> 10544 manuals both show the use of the 723 for the regulator for the
> oscillator supply,
>> but on the HP schematic for the 6198 board they use a pair of three
> terminal
>> regulators.
>
> HP's use of an LM317T-style regulator to drive the 18V oven supply, a 78L12
> to drive the oscillator, and a Zener+emitter follower to drive the 7474
> divider was a bit funky.  Regulator noise on the oven supply isn't critical,
> but for driving the oscillator circuit itself, the difference between a 7812
> and an LM317T can be seen in some cases.  Not sure offhand how sensitive the
> 10811 is to supply noise, but you can certainly see the difference in
> regulators with a Wenzel ULN.
>
> In any event an LM317T would be fine for driving the +12 rail.
>
> -- john, KE5FX
> Miles Design LLC
>
>
>
>
> ------------------------------
>
> Message: 3
> Date: Wed, 1 May 2013 13:36:43 +1000
> From: Jim Palfreyman <jim77742 at gmail.com>
> To: Discussion of precise time and frequency measurement
>     <time-nuts at febo.com>
> Subject: Re: [time-nuts] HP5065B !!!
> Message-ID:
>     <CALH-g5YNYi2o4wGJmzPDciCt8+hPGjfx0QPnjG1Ew+h0KGXXWA at mail.gmail.com>
> Content-Type: text/plain; charset=windows-1252
>
> Am I missing something? What actual modifications were done and how?
>
> Jim
>
>
>
> On 1 May 2013 07:30, <EWKehren at aol.com> wrote:
>
>> Attilla
>> No  one should or will discourage you from developing a laser pumped  Rb.
>> Bruce posted the following link. It addresses some of the issues and for
> me
>> looking at lamp Rb's is most helpful.
>>
>> http://tf.boulder.nist.gov/general/pdf/1219.pdf
>>
>> Bert Kehren
>>
>>
>>
>> In a message dated 4/30/2013 4:51:57 P.M. Eastern Daylight Time,
>> attila at kinali.ch writes:
>>
>> On Mon,  29 Apr 2013 17:19:05 -0400 (EDT)
>> EWKehren at aol.com wrote:
>>
>> > I am  still sitting here trying to figure out the purpose  of posting
> the
>>
>> > article on laser diode pumping of the Rb. One look at the data  and it
>> is
>> > clear that Corby?s work far surpasses the data shown in the  paper. All
>> it does
>> > is distract from Corb?s  accomplishments.
>>
>> Sorry i didnt mean to do that. I am very gratefull at  the work Corby
>> has done and the new insights on what error sources a Rb gas  cell
>> has.
>>
>> But as someone living in europe, i have certain problems  getting my
>> hands on a HP5065. There is virtually no surplus market here.  And
>> if there is anything sold in europe, the price is nearly that of
>> a  new device, sometimes even more (no, i'm neither joking nor
>> exagerating).
>> I  cannot buy any of the fancy devices you have access to in the US.
>> Buying a  Cs beam, as a few of you have, is a dream that will not come
>> true for me,  unless i win in the lottery.
>> But building my own Rb standard using laser  diodes is feasible.
>> I still lack a lot of knowledge and understanding how  to do that,
>> but this group has been very helpfull in filling my gaps, when  asking
>> the right questions. And if you don't mind, i would like to  keep
>> asking those questions.
>>
>>
>> Attila Kinali
>> --
>> The people on 4chan are like brilliant  psychologists
>> who also happen to be insane and gross.
>> --  unknown
>> _______________________________________________
>> time-nuts  mailing list -- 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: 4
> Date: Wed, 1 May 2013 12:40:02 +1000
> From: Jim Palfreyman <jim77742 at gmail.com>
> To: Discussion of precise time and frequency measurement
>     <time-nuts at febo.com>
> Subject: Re: [time-nuts] Time nut newbie
> Message-ID:
>     <CALH-g5ZoeGsGnfXj2SX=dL2cmHs+F+_VniG5p3KC4XXToP9Hxg at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> Buy a cheap rubidium off ebay and use it to drive a micro-controller and
> write some clock software.
>
>
> On 1 May 2013 11:57, Rex <rexa at sonic.net> wrote:
>
>> It doesn't affect the general magnitude conclusions by Bruce, but as long
>> as we are making corrections, my calculator seems to think
>> 60 * 60 * 24 * 12 = 1036800 seconds in 12 days, not 1024800.  That does
>> come out to 115.7 days for 1 sec error. Maybe the 12-day number was a
> typo?
>>
>> -Rex
>>
>>
>>
>> On 4/30/2013 12:57 PM, Bruce Griffiths wrote:
>>
>>> 12 days is 1024800 s ie just over 1 million seconds so a frequency offset
>>> of 0.1ppm results in a time error of ~ 0.1s not 1s.
>>> 1sec error would occur in just under 116 days,
>>>
>>> Bruce
>>>
>>> Bob Camp wrote:
>>>
>>>> Hi
>>>>
>>>> If you take a look down in the fine print on the OCXO spec, the aging
>>>> rate
>>>> is 100 ppb / year in the first year. If you are off by 0.1 ppm (100 ppb)
>>>> your clock will gain a second in less than 12 days.
>>>>
>>>> Bob
>>>>
>>>>
>> ______________________________**_________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/**
>>
> mailman/listinfo/time-nuts<https://www.febo.com/cgi-bin/mailman/listinfo/tim
> e-nuts>
>> and follow the instructions there.
>>
>
>
> ------------------------------
>
> Message: 5
> Date: Tue, 30 Apr 2013 23:13:44 -0700
> From: Hal Murray <hmurray at megapathdsl.net>
> To: lists at lazygranch.com, Discussion of precise time and frequency
>     measurement    <time-nuts at febo.com>
> Subject: Re: [time-nuts] Time nut newbie
> Message-ID:
>     <20130501061344.DB93980006F at ip-64-139-1-69.sjc.megapath.net>
> Content-Type: text/plain; charset=us-ascii
>
>
> lists at lazygranch.com said:
>> A bit OT, but back in the day there was what amounted to an X-prize for a
>> real accurate chronometer for navigation.
>
>> Make that way back in the day.
> http://en.m.wikipedia.org/wiki/John_Harrison
>
> There is a good book out on that topic:
>   Longitude by Dava Sobel
>   There is also a fancy version with lots of very good pictures.
>   I'll have to go find my copy so I can look at them again.
>
>
>
> --
> These are my opinions.  I hate spam.
>
>
>
>
>
> ------------------------------
>
> Message: 6
> Date: Tue, 30 Apr 2013 23:36:57 -0700
> From: Chris Albertson <albertson.chris at gmail.com>
> To: Discussion of precise time and frequency measurement
>     <time-nuts at febo.com>
> Subject: Re: [time-nuts] Time nut newbie
> Message-ID:
>     <CABbxVHuUjp3Af0tpkRG6E26BrSQGQviMCRi3wzgSYT9+OfzSHw at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> On Tue, Apr 30, 2013 at 7:40 PM, Jim Palfreyman <jim77742 at gmail.com> wrote:
>> Buy a cheap rubidium off ebay and use it to drive a micro-controller and
>> write some clock software.
>
> That was exactly my solution but I'm waiting ti hear about his size,
> power and cost budget.  If this has to run on Battery power for the
> entire year the Rb unit is not going to work
>
> The OP's 1 second per year goal is only asking for 3.2E-7 level
> performance if I did the math correctly.  Even the $100 Rb is at
> least 100 times better than required.
> --
>
> Chris Albertson
> Redondo Beach, California
>
>
> ------------------------------
>
> Message: 7
> Date: Wed, 1 May 2013 09:45:06 +0200
> From: Attila Kinali <attila at kinali.ch>
> To: Discussion of precise time and frequency measurement
>     <time-nuts at febo.com>
> Subject: Re: [time-nuts] Time nut newbie
> Message-ID: <20130501094506.966146722efbbaf9c80e5aca at kinali.ch>
> Content-Type: text/plain; charset=UTF-8
>
> On Tue, 30 Apr 2013 13:49:43 -0400
> "Tim Bastian"<n714x at yahoo.com> wrote:
>
>
>> I'm a time nut newbie. My obsession started with the search for an
> accurate chronometer to carry on my boat for celestial navigation. Yes there
> still are a few of us left that practice the art.
>>
>> My current project is a quartz chronometer using a DS32Khz tcxo oscillator
> and two 74HC4060s (+ or- 10 seconds / year).?
>>
>> For my next project I'm looking at an Abricon Part Number
> AOCJY2-10.000MHZ? ocxo 5 ppb running through a pic and using the algorithm
> posted on http://www.romanblack.com/one_sec.htm. I'm shooting for + or - 1
> seconds / year.?
>>
>>  Is there an archive of old posts that might be helpful in answering some
> of my questions and for getting ideas.
>
> You want to read Vig's Quartz Crystal Tutorial. That explains a lot about
> where the instabilities of a crystal oscillator come from. You can find
> them (and a lot more) on http://www.ko4bb.com/ in the Manuals section.
> Have a look at different versions, as some interesting things were left
> out in the newer versions.
>
> An idea how to get to the stability you want without wasting too much
> power might be an MCXO. [1] gives a pretty decent overview of the way how
> they work including a schematic for an oscillator. [2] has some ideas how
> to simplify the circuit and get lower power.
>
> In your case, i guess it would be an idea to leave out the second stage
> frequency generation (the VCO or DDS) and generate a PPS directly from
> the microcontroller.
>
>             Attila Kinali
>
>
> [1] "A microcomputer compensated crystal oscillator using a
> dual-mode resonator", by Benjaminson and Stallings, 1989
>
> [2] "An Improved Method of MCXO", by Zhou, Liu, Wang, 2000
> --
> The people on 4chan are like brilliant psychologists
> who also happen to be insane and gross.
>         -- unknown
>
>
> ------------------------------
>
> Message: 8
> Date: Wed, 1 May 2013 07:00:33 -0400
> From: Bob Camp <lists at rtty.us>
> To: Discussion of precise time and frequency measurement
>     <time-nuts at febo.com>
> Subject: Re: [time-nuts] Time nut newbie
> Message-ID: <7D23F52C-1BC6-449B-A47E-FC9BCC454E3A at rtty.us>
> Content-Type: text/plain; charset=windows-1252
>
> Hi
>
> It was tired old eyes and tiny numbers on the calculator ?.That plus to much
> distraction to double check things.
>
> Bob
>
> On Apr 30, 2013, at 9:57 PM, Rex <rexa at sonic.net> wrote:
>
>> It doesn't affect the general magnitude conclusions by Bruce, but as long
> as we are making corrections, my calculator seems to think
>> 60 * 60 * 24 * 12 = 1036800 seconds in 12 days, not 1024800.  That does
> come out to 115.7 days for 1 sec error. Maybe the 12-day number was a typo?
>>
>> -Rex
>>
>>
>> On 4/30/2013 12:57 PM, Bruce Griffiths wrote:
>>> 12 days is 1024800 s ie just over 1 million seconds so a frequency offset
> of 0.1ppm results in a time error of ~ 0.1s not 1s.
>>> 1sec error would occur in just under 116 days,
>>>
>>> Bruce
>>>
>>> Bob Camp wrote:
>>>> Hi
>>>>
>>>> If you take a look down in the fine print on the OCXO spec, the aging
> rate
>>>> is 100 ppb / year in the first year. If you are off by 0.1 ppm (100 ppb)
>>>> your clock will gain a second in less than 12 days.
>>>>
>>>> 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.
>
>
>
> ------------------------------
>
> _______________________________________________
> 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 106, Issue 1
> *****************************************
> _______________________________________________
> time-nuts mailing list -- 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.



--

Chris Albertson
Redondo Beach, California


More information about the time-nuts mailing list