[time-nuts] Did a member of time-nuts buy this?

Mike Monett timenuts at binsamp.e4ward.com
Tue Dec 9 06:10:45 EST 2014

Hi Bob, I have been having problems posting this. If other versions
show up, please disregard.

I have some questions for you.


> If you toss a Rb into the GPSDO "mix" things can get quite good.
> The Rb *should* be better than an OCXO in the > 1,000 second
> range.

> It's crossover with the GPS ADEV will be further out than the
> OCXO's. The gotcha with both the OCXO and Rb is their temperature
> dependance. Some / many / all of the lower cost Rb's are not much
> better than a good double oven OCXO in terms of raw temperature
> performance. The approach they use to "correct" this does not help
> their ADEV at all. Yes, you can disable the correction and put the
> whole thing in a temperature controlled environment.

What does the temperature controller do that degrades the ADEV? Can
anything be done to modify it to improve the performance?

> Lots of details to take care of. If you get them all right, you'll
> beat any / all of the older Cs standards.

Is there a list anywhere of all the details that need to be
addressed? How about words or phrases that can be used to search
google and the archives?

> One very cute addition would be to pull down the NIST GPS data and
> use it to correct your system on an hourly / daily basis. If you
> do that with common view satellites, you most certainly will beat
> a surplus grade Cs standard.

How can we do this? The NIST archives state

"The archive is only updated once every 24 hours, so data are not
available for today's date. Data from the previous day are added to
the archive at about 1600 UTC."


Is there another page that has current data? If so, how do we
incorporate it into the GPSDO?




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