[time-nuts] Z3801A OCXO manual trimming

[Mark Sims]

Or, it you are sure it's the OCXO,   go shopping for a new one.    There is a reputable seller with them (the double oven version) for $100 on Ebay.

A couple of things to try...  monitor the EFC voltage, power up the unit, and see if it is changing as it attempts to lock.   If  it does not, you may have a DAC problem... I don't think the Z3801 remembers the last DAC voltage to speed up the initial lock, so it should be searching for the lock voltage.

Also monitor the OCXO output and see how it changes as it warms up.   It should start out several Hz off and converge to 10 MHz as it warms up.   

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> Either tear into the OCXO or go shopping for a new(er) GPSDO.