[ntp:questions] Re: soekris 4501 that won't settle

Joshua Coombs jcoombs at gwi.net
Tue Mar 21 04:27:29 UTC 2006

"Joshua Coombs" <jcoombs at gwi.net> wrote in message 
news:P7adnXboCdsf4oLZRVn-pw at gwi.net...
> My nanobsd testbed has decided to drive me up a wall.  When I set it 
> loose, it starts hunting for a pll adjustment value, swinging wider 
> and wider with each period.  When I last restarted ntpd to try a 
> conf change, it was varying the pll freq by 40ppm over the course of 
> one of it's sweeps.
> Plotting the adjustment value over time generates a lovely sine wave 
> with a static period but an exponentially growing amplitude centered 
> on -25ppm.

An interesting extra data point, the period seems to be approx 6.8 
hours for it to sweep the pll freq from a high, to a new low, back up 
to a new high.  That works out to being 12 poll intervals nearly 
exactly using my 2048 poll period?

Joshua Coombs 

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