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

Brooke Clarke brooke at pacific.net
Tue Apr 5 11:53:18 EDT 2005

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,


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.
> _______________________________________________
> time-nuts mailing list
> time-nuts at febo.com
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts

w/Java http://www.PRC68.com
w/o Java http://www.pacificsites.com/~brooke/PRC68COM.shtml

More information about the time-nuts mailing list