Hi Any time you change the operating point of the sustaining circuit (limiter / amp) in an OCXO, there’s a chance that the drive level changes. For small changes in operating point, (and the absence of perturbations) you rarely will see any impact. For large changes (or tuning onto a perturbation), you can see impact on the ADEV. If it’s a drive level change, it probably will settle out.
Bob > On Nov 26, 2014, at 9:04 PM, Mark Spencer <[email protected]> wrote: > > I've long had a nagging suspicion that OCXO's that are not adjusted will in > practice have lower ADEV than ones that are tweaked regularly. Several days > ago I noticed that one of my 10811's was performing quite well (I believe > this is the first time any of 10811's have delivered adev / madev numbers in > the 13's) and this was sustained for approx 2 days. After trimming the > frequency and letting it sit for a number of hours I noticed the adev was > notably worse. > > I realize there could be a mechanical issue with the trimmer inside the ocxo > that is causing this or simply touching the ocxo while adjusting it may have > also caused this, but is changing the frequency of an OCXO in of it self > likely to have an affect on ADEV / MADEV after a few hours ? > > Looking at the linear residual plot of the phase difference between the 10811 > and the reference, I see a fairly large difference at first, then a somewhat > smaller change, then a series of smaller changes. But I may be reading to > much into this plot. > > I don't expect an absolute answer to this but I'm curious if anyone else has > seen this. > > > Sent from my iPad > _______________________________________________ > 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.
