Hi Both control loops in the 3801 OCXO’s are thermistor based. If the outside loop goes nuts, the device might survive. If the inside loop shorts out, the normal result is a melt down of the OCXO innards.
Bob > On Jun 2, 2022, at 9:55 AM, K5jv via time-nuts <time-nuts@lists.febo.com> > wrote: > > I was recently evolved in a discussion about the HP 58503 option 001 display. > The general idea is that there is some command to tune the display on or > off. A few ideas were offered but no one had anything except "they heard > about it." I have found nothing on the subject from old HP literature. > Comments would be appreciated. I am not talking about turning the power off > to the DC/DC converter. > > On a different subject: A couple of month back I got some strong criticism > about suggesting that the oven in the Z3801A was a potential source of > problems. I just got another Z3801A in for repair. Same symptoms as > before; appears to turn on normally but after a while goes into holdover and > stay there, same LH flat lines. Once again the problem turned out to be the > oven. It was unusually hot to the touch. Changing the oven solved the > problem. Now my question. I have never opened one of these oven, so have no > real idea exactly what is inside. I would suspect that one of the oven's > thermostats is stuck in the "on" position. Since it is a "double oven", > there could be two thermostats? If these are mechanical contacts, as one > might expect fro the 1995 era, can they be cleaned or replaced? Comments > from anyone who has actually seen inside one of these ovens would be > appreciated. > > > 73 de Lon, K5JV > 281-795-1335 > > > [a96323c7-47c0-46b2-8018-f039618476d5] > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe send an email to time-nuts-le...@lists.febo.com _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe send an email to time-nuts-le...@lists.febo.com
