Hi Matthias - It sounds like you may have a temperature sensitive component (or solder joint?).
Perhaps cooling each component individually will help you find the problem. Regards, John K1AE -----Original Message----- From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Matthias Jelen Sent: Tuesday, June 09, 2015 2:31 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] HP5370 Error 04 Hello John, thanks for that information. Unfortunately, my fan is working. Opening the lid and putting an extra blower to cool the VCO helps to extend the time until he error occurs... Regards, Matthias > Hello Matthias - I had this problem on my 5370B - it turned out that the fan > wasn't running, which resulted in overheating. > > I hope this helps. > > Regards, John K1AE > > -----Original Message----- > From: time-nuts [mailto:time-nuts-boun...@febo.com] On Behalf Of Matthias > Jelen > Sent: Monday, June 08, 2015 9:28 AM > To: time-nuts@febo.com; dk...@gmx.de > Subject: [time-nuts] HP5370 Error 04 > > > Hello! > > I´ve got a question to the 5370 experts on the list. > > I just received my new (old...) HP5370a. It performed fine for abt. one hour, > then it started to display error 04 which means "PLL out of lock". > > A look in the service manual revealed that there are several reasons for > this. I checked the VCO voltage on both interpolator cards, and indeed, one > of them is out of the specified -6V..-3V, it runs to the rail (-12V). Even if > the error is not there, the voltage is at abt. -7 V, so I guess it´s just on > the edge. The other card is fine. > > Normally, I´d try the alignment procedure, but I´m missing the exotic HP > pulse generator used for the alignment and I have no clue how I could easily > substitute this one. > > Did anyone encounter this problem before? Is there a cure for this problem > known to the experts? Any hints are highly appreciated... > > Thanks a lot, > > Matthias, DK4YJ > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > > > --- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus > > _______________________________________________ > time-nuts mailing list -- time-nuts@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@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
