[time-nuts] GPS: ADEV or MDEV?

[SAIDJACK at aol.com]

In a message dated 4/23/2007 20:51:28 Pacific Daylight Time,  bruce
.griffiths at xtra.co.nz writes:

>Of  course one can always resort to annealing out the retrace by  
>controlled thermal cycling of the reference as Fluke (optionally) do  in 
>their 7000 series references whenever continuous power is  lost.
>These 10V references use selected LTZ1000's to achieve a drift of  around 
>1ppm/year.

>Bruce



Nice performance on the Fluke. Agree on the thermal sensitivities of the  
DAC, reference etc. Long term Zener aging not so important for a GPSDO  of course.
 
BTW: I know of a test lab that "officially" tested a Fluke GPSDO for  someone 
I know only to find it was not better than 1E-09.
 
They maintained that the unit was not broken, just bad...
 
bye,
Said



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