[time-nuts] GPSDO won't lock: OCXO aged out?

[Oz-in-DFW]

On 1/15/2021 8:30 PM, paul swed wrote:
> Not sure how hard it might be to get a thermocouple into the oven. That
> would give you a hint.
> Regards
> Paul
Seems to me you already have a temperature sensor in the OCXO.

If you temperature soak it overnight and monitor the frequency as power 
is applied, you should see the starting freq of the oscillator.  The 
heater will come on immediately and start it warming up, but the 
oscillator should stabilize in less than a 100 ms or so, and the heater 
should not be a major factor.  Do this at several temps and you should 
get a pretty decent picture.

I suspect the fly in the ointment in this approach is that the oven temp 
is usually picked to be around the flattest spot in the temp/freq curve. 
You may not see much resolution.

You can also monitor oven current which I guess should translate to a 
temperature error term, though I'm not sure off hand how you'd calibrate 
that.

Oz (in DFW)