[time-nuts] GPSDO recovery from holdover

Hal Murray hmurray at megapathdsl.net
Sat Dec 1 02:10:35 UTC 2012

Does anybody know what happens in a TBolt or Z3801?  (or any other boxes?)

Suppose your system goes into holdover for long enough to be interesting.  
Suppose for discussion that the clock drifts so that the PPS if off by a 

I can see two ways to recover.  One is to jump the 10 MHz clock by 10 cycles. 
 The other is to adjust the frequency so that the PPS slews back to on-time.

The first approach gives you a second with the wrong number of cycles.  The 
second approach has your clock frequency off for a while with a trade off 
between how far off and how long it's off.

Are there any other approaches?

These are my opinions.  I hate spam.

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