If you're thinking it's the 10811, here's something to try: Arrange to measure output frequency, and tune voltage, and put the curves up on a dual-trace o'scope. If the output frequency fluctuations correlate in the correct direction of the tune voltage fluctuations, then the problem is probably not in the 10811. But if the tune voltage appears to be fighting the output frequency variations, then it's most likely to be the 10811 (or perhaps just its power supply source) who's at fault.
Dana On Sun, Dec 13, 2020 at 6:31 PM Bob kb8tq <[email protected]> wrote: > Hi > > If the inside of the 105 went under water long enough to rust out a lot > of parts on the boards, it’s a good bet that the 10811 in the unit got > hit pretty hard as well. > > Simple answer: Spend $40 on an eBay replacement for the 10811. > It should just plug in …. > > Bob > > > On Dec 13, 2020, at 5:15 PM, Dave Miller <[email protected]> wrote: > > > > I am in the middle of resurrecting a HP105B, It is one of the later > models > > with an 10811 in. > > > > I have fixed the obvious issues like the electrolytics that were missing > > and other parts that had leads evaporated due to corrosion. > > > > The basics seem to work, A not bad looking sine wave etc. > > But the ADEV numbers are terrible. > > I am going back to make sure it's not a measurement setup issue. That is > > good. Just tested another OCXO and the test setup is good. > > Attached in a link to a .tim file > > https://www.dropbox.com/s/zebwiqy913v7k0k/HP105B%20test.tim?dl=0 > > I am hoping one of the more knowledgeable folks might suggest where to > > start looking. > > I have checked all the other electrolytics and the ESR and capacitance > > looks good. I think the power supply seemed clean. > > > > I have taken out the easy to get boards and cleaned card edges etc but > this > > persists. > > > > The saw tooth on the original phase is yelling something at me but I > > don't have a clue. > > > > Thanks > > Dave > > > > -- > > 72 de Dave > > VE7HR > > _______________________________________________ > > time-nuts mailing list -- [email protected] > > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > > and follow the instructions there. > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
