[time-nuts] time-nuts Digest, Vol 31, Issue 10

Howard W. Ashcraft hashcraft at hansonbridgett.com
Sat Feb 3 04:45:36 EST 2007



     his communication, including any attachments, is confidential and is protected by privilege.  If you are not the intended recipient, any use, dissemination, distribution, or copying of this communication is strictly prohibited.  If you have received t

 -----Original Message-----
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Sent:	Friday, February 02, 2007 08:56 PM Pacific Standard Time
To:	time-nuts at febo.com
Subject:	time-nuts Digest, Vol 31, Issue 10

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Today's Topics:

   1. Re: HP10544a Technical Info needed (Dr Bruce Griffiths)
   2. Re: HP10544a Technical Info needed (Tom Van Baak (mobile))
   3. Re: HP10544a Technical Info needed (Gerald Molenkamp)
   4. Re: HP10544a Technical Info needed (Dr Bruce Griffiths)
   5. Re: HP10544a Technical Info needed (Dr Bruce Griffiths)


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

Message: 1
Date: Sat, 03 Feb 2007 17:01:14 +1300
From: Dr Bruce Griffiths <bruce.griffiths at xtra.co.nz>
Subject: Re: [time-nuts] HP10544a Technical Info needed
To: Discussion of precise time and frequency measurement
	<time-nuts at febo.com>
Message-ID: <45C4090A.7000100 at xtra.co.nz>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Gerald Molenkamp wrote:
> Hi Howard,
>
> Please find attached a schematic of the 10544, hope it helps in anyway.
>
> Regards
>
>
>
> Gerald
>
Gerald

The connection of the 10K oven monitor resistor R12 in the schematic is 
incorrect.
In this position only the very small deviations in the oven supply 
voltage due to its finite output impedance will be seen as Q4 turns on 
and off.
The resistor should surely be connected to the junction of the 
darlington (Q4) emitter and the oven heater winding resistor??
The datasheet clearly states that the duty cycle of the oven monitor 
varies, as is seen with working 10544As.

Bruce



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

Message: 2
Date: Fri, 2 Feb 2007 20:10:53 -0800
From: "Tom Van Baak \(mobile\)" <tvb at LeapSecond.com>
Subject: Re: [time-nuts] HP10544a Technical Info needed
To: "Discussion of precise time and frequency measurement"
	<time-nuts at febo.com>
Message-ID: <001401c74749$4c5063b0$0300a8c0 at pc52>
Content-Type: text/plain; format=flowed; charset="Windows-1252";
	reply-type=original

> Hi Howard,
> 
> Please find attached a schematic of the 10544, hope it helps in anyway.

Wonder where you got that one ;-)

http://www.leapsecond.com/museum/10544/

I scanned and posted that in 2001; but didn't check the
manual against an actual 10544 oscillator. Should be
close enough for a repair, though.

/tvb
http://www.LeapSecond.com





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

Message: 3
Date: Sat, 3 Feb 2007 15:21:44 +1100
From: "Gerald Molenkamp" <geraldm at iprimus.com.au>
Subject: Re: [time-nuts] HP10544a Technical Info needed
To: "Discussion of precise time and frequency measurement"
	<time-nuts at febo.com>
Message-ID: <014d01c7474a$d2355110$0158a8c0 at GMPC>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
	reply-type=original

Hi Bruce,

You are right. I havn't checked my unit against the schematic at all. It is 
well secured calibrated and operating in my HP 5342 operating well within 
the specifications. The scanned schematic came from Leapsecond a few years 
ago, and I have not had to use it as yet. Lets hope it stays that way.

Cheers

Gerald


----- Original Message ----- 
From: "Dr Bruce Griffiths" <bruce.griffiths at xtra.co.nz>
To: "Discussion of precise time and frequency measurement" 
<time-nuts at febo.com>
Sent: Saturday, February 03, 2007 3:01 PM
Subject: Re: [time-nuts] HP10544a Technical Info needed


> Gerald Molenkamp wrote:
>> Hi Howard,
>>
>> Please find attached a schematic of the 10544, hope it helps in anyway.
>>
>> Regards
>>
>>
>>
>> Gerald
>>
> Gerald
>
> The connection of the 10K oven monitor resistor R12 in the schematic is
> incorrect.
> In this position only the very small deviations in the oven supply
> voltage due to its finite output impedance will be seen as Q4 turns on
> and off.
> The resistor should surely be connected to the junction of the
> darlington (Q4) emitter and the oven heater winding resistor??
> The datasheet clearly states that the duty cycle of the oven monitor
> varies, as is seen with working 10544As.
>
> Bruce
>
> _______________________________________________
> time-nuts mailing list
> time-nuts at febo.com
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts 



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

Message: 4
Date: Sat, 03 Feb 2007 17:32:07 +1300
From: Dr Bruce Griffiths <bruce.griffiths at xtra.co.nz>
Subject: Re: [time-nuts] HP10544a Technical Info needed
To: Discussion of precise time and frequency measurement
	<time-nuts at febo.com>
Message-ID: <45C41047.7020906 at xtra.co.nz>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Gerald

Its about 30 years since I had one of these apart for (sucessful) repair 
without the aid of any circuit diagram.
At least one can calculate that the nominal crystal current is about 240 
uA rms somewhat less than the 1mA in the 10811 with its SC cut crystal.

Bruce
Gerald Molenkamp wrote:
> Hi Bruce,
>
> You are right. I havn't checked my unit against the schematic at all. It is 
> well secured calibrated and operating in my HP 5342 operating well within 
> the specifications. The scanned schematic came from Leapsecond a few years 
> ago, and I have not had to use it as yet. Lets hope it stays that way.
>
> Cheers
>
> Gerald
>   



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

Message: 5
Date: Sat, 03 Feb 2007 17:54:45 +1300
From: Dr Bruce Griffiths <bruce.griffiths at xtra.co.nz>
Subject: Re: [time-nuts] HP10544a Technical Info needed
To: Discussion of precise time and frequency measurement
	<time-nuts at febo.com>
Message-ID: <45C41595.6080801 at xtra.co.nz>
Content-Type: text/plain; charset="iso-8859-1"

Howard

Attached GIf file depicts the recommended power supply filtering when 
the oven circuit shares the same supply as the oscillator.

Bruce

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