Quote:
Originally Posted by Radio1950
If there is any doubt, if there is any slow circle wander, even very slow, there is a problem, and you have to rethink the process.
A GPSDO with an output frequency within a few Hz of nominal is not operating correctly.
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This is my current dilemma. The lissajous test gives me a wandering circle so I know that one of the references is not accurate. The one I borrowed is a commercial unit based on a Trimble core so I’m inclined to trust that.
Investigating my DIY version, I have no confidence that the GPS 10kHz is having any effect on the OCXO. Fiddling with the resistors in the feedback circuit gets me to about 2 phases per second but it not locked, removing the antenna from the GPS (which should disturb it enough to be measurable) doesn’t make any difference.
I believe that I should be able to get two GPSDO to give me a perfect lissajous circle after they have settled - but these have both been running in the bench now for a week.