[time-nuts] Re: Efratom LPRO-101 Rubidium question....

[Matthias Welwarsky]

Hi,

a Rb will not be long-term accurate. I'd trust a GPSDO to be long-term 
accurate. A hundreds-of-Hz offset between the LPRO and the GPSDO certainly 
points into the direction of the LPRO being off the mark.

When you adjust the LPRO, be sure to give it ample time to stabilize.

BR,
Matthias

On Samstag, 21. August 2021 14:50:24 CEST mpb45 at clanbaker.org wrote:
> Hello Time-Nutters--
> 
> I am working on building a downlinking AZ/EL tracking dish set up to
> receive the 8.2 GHz telemetry from the Suomi JPSS polar orbit
> meteorological/environmental satellite.  The receiver seems to be
> working OK but it periodically appears to slowly drift frequency by
> 300 Hz to 400 Hz.  I need some way to accurately determine what
> the actual RX receive frequency is.
> 
> I have a vintage Efratom LPRO-101 Rubidium 10 MHz oscillator.
> I originally got it thinking that it would provide a decent
> phase-lock reference for my freq-counters, o-scopes, spectrum
> analyzers and Agilent/HP vector network analyzer.
> 
> The only other item I have that has (or should have) a reasonably
> accurate 10 MHz reference output is a Trimble Thunderbolt.
> However, there is a several hundred Hz freq difference between the
> Efratom and the Trimble T-bolt.
> 
> My question is how do I go confirming the frequency of the T-Bolt
> or the Efratom Rubidium?  The Efratom has an adjustment pot
> to fine-tune its output frequency.  How do Time-Nutters go about
> confirming the accuracy of frequency references such as my
> T-Bolt or Efratom rubidium oscillator?
> 
> Thanks for any feedback / suggestions on this !!
> 
> Off-list communications on this via my email is OK!!
> 
> Mike Baker   mpb45 at clanbaker.org
> Micanopy/Gainesville  North Central Florida
> **********************
> 
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