[time-nuts] How can one measure ADEV of a good oscillator?
Richard (Rick) Karlquist
richard at karlquist.com
Mon Dec 1 19:23:32 EST 2014
On 12/1/2014 4:08 PM, Bob Camp wrote:
> Others did a similar thing by simply taking production OCXO’s to the limit of their EFC range. That let you do a coarse sort to find some number of “likely” units. Next step was to pop a few of them open and short this or that out to get a reasonable beat note. Numbers in the 10 to 20 Hz range were pretty common. After that a single mixer setup followed by a simple limiter got things good enough to screen the production lots.
I am fairly sure they would have done that if it was workable,
to avoid special crystals. One rather huge problem with a
10 Hz beat note is that you are never going to measure ADEV
at short (<1 second) sample times that way.
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