[time-nuts] Racal-Dana 1992 switches
rexa at sonic.net
Wed Apr 2 18:01:24 EDT 2008
Bruce Griffiths wrote:
> 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.
The result was fine, but the measurement should have been 40.000 000 003
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