[time-nuts] Rb vs.Crystal OCXO
Tom Van Baak
tvb at LeapSecond.com
Sat Apr 26 22:15:19 EDT 2014
> The thunderbolt is one of the best timing devices but not for frequency, if
> you want high resolution. Over time it is ok but high resolution short
> gate times and you see the frequency changes. They use the OCXO to correct for
> timing error and if you have a Tracor 527E you can see it. Also how else
> do you think they control the 1 pps.
> Bert Kehren
Put your TBolt (or any other GPSDO) in holdover (freeze the DAC) and then take a close look again. Tell me what you see. The difference (if any) is due to steering. What's common (if any) is due to the OCXO itself.
Have a look at http://leapsecond.com/pages/gpsdo/ to see the results for 4 common GPSDO. Focus on the left edge of the plots only. Note also that tuning parameters can make a big difference in the results (I used only defaults for those plots).
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