[time-nuts] Frequency comparison

Joop lous at xs4all.nl
Mon Feb 8 22:51:53 UTC 2010


>Since the GPSDO takes > 1 1/2 hours to give an adequately accurate
reading
>to calibrate 1x10^-11, there's no rushing the process. That's not warm up
>time, or lock time on the GPSDO. It's the time you need to watch if for
in
>order to know it's output frequency to a sufficient level of precision. 
>
>Bob
>
Yes, I noticed these things take time ;-)

This is what I logged after everthing was powered on for over 24 hours and
adjusted. 
It is a 2 hour period during which no adjustments were made.
http://www.uploadarchief.net/files/download/lpro_24h.png

And this is with the LPRO is cold started. About 5 minutes after lock.
The GPS was already running for about an hour I have to guess. The LPRO
was not adjusted anymore.
http://www.uploadarchief.net/files/download/lpro_start7h.png
It is less flat at the last two hours than what I was hoping for.

Joop




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