[time-nuts] RE: phase locking Rb to GPS

[Alberto di Bene]

Bill Hawkins wrote:
> Speaking as a process control engineer, it sounds like
> too much gain. You can verify that it is the oven by 
> warming up the device somehow. That should change the
> period of oscillation. If it is still 7 minutes then
> reduce the gain somehow.
> 
I can't reduce the gain of the temperature controlling
circuitry, as it is sealed inside the oven. The only thing
I have control of, is the EFC voltage applied to the OCXO.
I made an experiment when testing the GPSDO, I blew on the
ovened oscillator assembly, and measured the EFC changes,
translated into frequency changes. The plot is in the attached
file. The long recovery time is caused by the long time 
constant of the EFC controller.

73  Alberto  I2PHD
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