[time-nuts] OCXO Phase Noise Measurement in Primitive Conditions

Bob Stewart bob at evoria.net
Wed Aug 27 13:01:19 EDT 2014

I have my GPSDO developed well enough now that I'm correcting for the quantization error given by my LEA-6T.  As I watch the phase difference plot, it seems a bit more noisy than it should be.  I've also had to make the DAC pretty active to keep the phase noise on a short leash.  So, I'm wondering what I have around here that I can use to measure the phase noise of my OCXO.

For test equipment I have:

My ex-telecom Rb that I turned on last night  showed poor frequency stability over night, so I'm going to let it bake for a day or two to see if that improves.

An HP 10811 standard in my 5335A, and the 5335A itself to measure time interval.  I have GPIB and I can capture the TI from the 5335A.

An ADR-291 Voltage Reference to lock the EFC of the OCXO to a known value.

My thought was to begin by locking the DAC to a single value and plot an ADEV against the Rb.  Is there anything else I can do with this somewhat primitive time lab?

Bob - AE6RV

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