[time-nuts] GPSDO Short Term tests

[Andy Talbot]

While my next plot of Droitwich is being generated at this moment, for the
meantime here's an analysis of the short term stability of the Leo-Bodnar
GPSDO made a couple of years ago.   It was done by multiplying the
output up to 10GHz and comparing with a caesium derived reference
multiplied up.

The results, which show the performance over the tens of seconds to minutes
time frame can be seen here .
http://www.g4jnt.com/ShortTermStabilityLeoBodnarGPSDO.pdf

Compare this with a test done a few days ago, comparing the 10MHz outputs
over a 30 minute period.
http://www.g4jnt.com/DropF/gpsdo_cs_10mhz_30min.bmp

This sort of short term stability reflects on how 'good' a GPSDO is when
used as a reference for a synthesizer for microwave Tx/Rx.   The artefacts
are just about audible at 5.76GHz when listening to a steady tone (they are
to me anyway, although it may be only a few Hz wobble) and very definitely
so at 24GHz and higher.

Andy
www.g4jnt.com