[time-nuts] Racal-Dana 1992 switches
bruce.griffiths at xtra.co.nz
Wed Apr 2 17:25:24 EDT 2008
Tom Duckworth wrote:
> I have attached a PDF of two methods we used at XL Microwave for adjusting
> the internal reference oscillators in our microwave counters. The second
> method (digital) was used to calibrate the internal reference time base of a
> 70 GHz microwave counter with an accuracy of parts in E-11.
> This digital method could be used to compare two GPSDOs, one to the other,
> and would probably yield greater resolution than trying to use a phase
> measurement on a counter due to jitter, internal noise, and stability issues
> in the count chain. This method proved to be fast, simple, stable, and
> superior to other methods we tried.
> Hope this helps.
> Tom Duckworth
The first calculation at the bottom of the second page is incorrect the
result should be: 1.25E-10 not 7.5E-11.
More information about the time-nuts