It was always intended for factory repair only so a service manual may not be readily available. The schematic is comprehensive enough that one hardly needs one. The tricky part is setting the oven temperature. There's probably a description in the relevant HP Journal (probably early 70's).
Bruce J. L. Trantham wrote: > I have been able to find schematics of the 10544A but not a service manual. > Is there a service manual available? > > Joe > > -----Original Message----- > From: [email protected] [mailto:[email protected]]on > Behalf Of Bruce Griffiths > Sent: Saturday, March 07, 2009 3:24 PM > To: Discussion of precise time and frequency measurement > Subject: Re: [time-nuts] About HP10544A > > Esa Heikkinen wrote: > >>> New 10544A's have a somewhat cleaner output than that. >>> Perhaps something is wrong with the emitter follower. >>> >>> >> Sorry I forgot to say that the oscilloscope picture was taken directly >> from HP10544A output, without emitter follower but with 1:1 probe, >> output terminated with 1 kohm. resistor. With spectrum analyzer the >> emitter follower is necessary due to 50 ohm. input impedance of the >> analyzer. >> >> Datasheet of HP10544A claims that harmonics should be more than 25 dB >> down. Doesn't look like they are. >> >> Here's a spectrum measured from OCXO which is used in the Thunderbolt. >> I'm not an crystal oscillator guru but I think that this is just what an >> xtal oscillator output should be: >> >> http://www.amigazone.fi/files/gpsdo/tbolt-1.png >> http://www.amigazone.fi/files/gpsdo/tbolt-2.png >> >> >> > Esa > > The capacitance of the 1x probe is too high. > Use a 10x probe with 1k across its inputs at the 10544A. > The 10544A output stage is an emitter follower. > > Bruce > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
