[time-nuts] 5061 Cs frequency shift with long time constant?

[Brooke Clarke]

Hi John:

My guess is that changing a time constant may be something like 
switching in a capacitor.  That may cause some ringing that may last 
days to weeks.

Have Fun,

Brooke

John Ackermann N8UR wrote:

> This is very odd (I seem to be collecting these sorts of problems) and 
> I wonder if anyone else has seen something similar.
>
> I got my 5061A trimmed to the point where a 5 day run against GPS 
> showed an offset of less than 1x10e-13.  I then switched the unit into 
> the long time constant mode and now see that the offset (over 36 
> hours) is -1.7x10e-12.  Nothing else in the setup has changed.
>
> It's hard for me to see how simply changing the loop time constant 
> would change the frequency of the standard, especially by this much, 
> but stranger things have happened.
>
> Has anyone else experienced a shift like this when switching the time 
> constant?
>
> Thanks,
>
> John
>
> PS -- I was able to partially, but not completely, reproduce the phase 
> shift that I wrote about a couple of weeks ago by jiggling the 1 PPS 
> cable to the counter.  Replacing that cable seems to have resolved 
> that problem.
>
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