[time-nuts] Disciplining Rubidium

Bruce Griffiths bruce.griffiths at xtra.co.nz
Thu Apr 24 02:43:51 EDT 2008

SAIDJACK at aol.com wrote:
> Hi Bruce,
> either way GPS can't give you parts to the 14 short term as was  claimed. 
> Also there are not many affordable carrier phase GPS receivers out  there as far 
> as I know.
> Also, 2 parts to the 11 over 1s - 100s is still not as good as a good OCXO  
> (parts to 12 or even 13 possible), so carrier phase performance from 1-100s  
> with parts to the 11 would not help the GPSDO perform better steady state short  
> term 1s to 100s.
> bye,
> Said

There's no particular reason that a GPS carrier phase disciplined OCXO 
need be particularly expensive unless of course it incorporates an 
Oscilloquartz 8607 with ultra low adev specs.
Suitable receivers seem to be readily available. The only major 
complication is the need to phase lock their local oscillator to the 
OCXO being disciplined. In some case this is easy as a 10<Hz crystal is 

You've misinterpreted the statement 2E-11/Tau actually  means:
2E-11 @ 1 sec
2E-12 @ 10sec
2E-13 @100 sec


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