Hi There is a very extensive calibration / alignment process for the 5370. It sounds a lot like your box was set up “cold” rather than after a proper warmup. There is a lot of “stuff” in there, so picking out exactly which adjustment is drifting is going to be a guessing game.
Bob > On Oct 26, 2015, at 3:55 PM, Matthias Jelen <matthias.je...@gmx.de> wrote: > > Hello Time-Nuts, > > once again a question to the 5370 experts: > > After some time of operation (hours...) my 5370A starts to become noisy. This > can be seen best when teeing the 10 MHz REF OUT to IN A nnd IN B, choosing TI > and setting STD DEV, 1k samples. When everything works well, the displayed > value is around 10 .. 14 ps. After some time, this values starts to rise > slowly and might grow up to several ns. The effect seems to be temperature > related, with the lid removed it takes longer until the unit starts to fail. > I used quite some cooling spray, and the front panel board seems to be > somewhat sensible, but I couldn´t find a part which, when cooled, returned > the display to the initial values. Cooling the whole frontpanel with an > external blower also helps. > > Then I noticed that I am able to bring back the display back to a few > picoseconds by switching arbitrary around with the trigger slope switches - > both channels seem to have an influence. After flipping them forth and back > several times, everything is OK again. I couldn´t find any systematic > behaviour behind this. > > Did anyone experience something similar? (and maybe even found a cure?) Any > hints will be highly appreciated... > > Best regards, > > Matthias > _______________________________________________ > 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.
