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

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----- From: time-nuts-request@febo.com [mailto:time-nuts-request@febo.com] Sent: Friday, February 02, 2007 08:56 PM Pacific Standard Time To: time-nuts@febo.com Subject: time-nuts Digest, Vol 31, Issue 10 Send time-nuts mailing list submissions to time-nuts@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@febo.com You can reach the person managing the list at time-nuts-owner@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: 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@xtra.co.nz> Subject: Re: [time-nuts] HP10544a Technical Info needed To: Discussion of precise time and frequency measurement <time-nuts@febo.com> Message-ID: <45C4090A.7000100@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@LeapSecond.com> Subject: Re: [time-nuts] HP10544a Technical Info needed To: "Discussion of precise time and frequency measurement" <time-nuts@febo.com> Message-ID: <001401c74749$4c5063b0$0300a8c0@pc52> Content-Type: text/plain; format=flowed; charset="Windows-1252"; reply-type=original > Hi Howard, > > Please find attached a schematic of the 10544, hope it helps in anyway. Wonder where you got that one ;-) http://www.leapsecond.com/museum/10544/ I scanned and posted that in 2001; but didn't check the manual against an actual 10544 oscillator. Should be close enough for a repair, though. /tvb http://www.LeapSecond.com ------------------------------ Message: 3 Date: Sat, 3 Feb 2007 15:21:44 +1100 From: "Gerald Molenkamp" <geraldm@iprimus.com.au> Subject: Re: [time-nuts] HP10544a Technical Info needed To: "Discussion of precise time and frequency measurement" <time-nuts@febo.com> Message-ID: <014d01c7474a$d2355110$0158a8c0@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@xtra.co.nz> To: "Discussion of precise time and frequency measurement" <time-nuts@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@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@xtra.co.nz> Subject: Re: [time-nuts] HP10544a Technical Info needed To: Discussion of precise time and frequency measurement <time-nuts@febo.com> Message-ID: <45C41047.7020906@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@xtra.co.nz> Subject: Re: [time-nuts] HP10544a Technical Info needed To: Discussion of precise time and frequency measurement <time-nuts@febo.com> Message-ID: <45C41595.6080801@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