I connected a Tbolt to the 1PPS input of a Symmetricom SA22.c rubidium
oscillator and ran Heather's software discipling code on it. For some strange
reason, you do get better performance using a clean 1PPS rather than the
crappiest one you can find ;-)
Anyway some interesting results came out. White traces are the DDS frequency
offset Heather is using to steer the SA22.c output freq, yellow are
temperature, magenta is the difference between the 1PPS in and 1PPS out (16.666
ns res of the SA22.c TIC). The straight white and yellow traces are linear
regression trend lines of those parameters. A little math shows a clear
dependence of the SA22 output freq on temperature of around 2.664E-11 parts per
degree C. This sort of agrees with a plot in the SA22.c data sheet that shows
the TC vs ambient temperature... if "ambient temperature" means the baseplate
temp reported by the unit.
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