[time-nuts] ensemble oscillators for better stability

cdelect at juno.com cdelect at juno.com
Fri Dec 28 19:12:26 UTC 2012


I've been playing around with 2 HP 5065A standards to see if averaging
them will give better stability.

The results so far are:

                     1 sec        10 sec    100 sec
unitA            1.28-12    3.83-13   1.33-13      
unitB            9.31-13    3.44-13   1.18-13
combined     8.95-13    3.09-13   8.95-14

Each unit was adjusted for equal amplitude into a resistive power
combiner and also adjusted so their phase was coincident prior to
starting the plots.
The main problem was getting their relative frequencies close enough so
that there was no drift during the measurements.
Not a trivial accomplishment for the 100 sec tau!

I'm thinking now of a way to loosely lock the phase of one unit to the
other to simplify the setup.

One different idea I had that I'd like some feedback on:

If I take both units into a double balanced mixer, then take the
resulting 10MHz and divide it back to 5MHz would I get the same

This method would be much simpler!

Happy New Year!

Corby Dawson

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