[time-nuts] Need help with 10811 behavior

[Skip Withrow]

Hello time-nuts,
I have been trying to characterize a couple of 10811 oscillators and have
some questions about their behavior and thought I would consult the hive
mind.

What I noticed was an ~1s ripple in the phase plot, this is really
noticeable on the ADEV plot.  So, to check that it was not my reference I
did the plot of MHM-A1 (my reference) against RUFUS (rubidium oscillator).
There are no funny ripples in that plot.  I then grabbed another 10811 to
check it, same sort of behaviour (even bigger ripples).

The 10811 units are being powered from two lab supplies (one for heater,
one for oscillator, which I believe are not the root of the problem).  I
have looked at the schematic for the 10811 and there is only one capacitor
that could create a time constant in this neighborhood (C18 2.0uF), then
there is probably the time constant of the heater/thermistor.

Any insight on this behaviour would be appreciated.  I have attached plots
of the ADEV and phase for the three runs.

Thanks in advance,
Skip Withrow
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