[ntp:questions] Very large jitter and offsets on GPS ref clock after upgrade to "p5"

David J Taylor david-taylor at blueyonder.co.uk.invalid
Tue Jan 10 18:29:48 UTC 2012


"unruh" <unruh at invalid.ca> wrote in message 
news:eg%Oq.48484$2e7.22518 at newsfe18.iad...
[]
>> pulse over the length of line he talks about should be no problem at 
>> all
>> (but a microsecond-wide pulse might).  The timing PPS I've seen are in 
>> the
>> tens of milliseconds wide.  If there is overshoot, perhaps a capacitor 
>> to
>
> Did you mean 10s of ns? The Sure width is about 5-10ns. at the card
> without any line attached. The line could certainly broaden that up to
> about 1us, but ms?
> Even the Garmin 18 is less than a usec.

The width of the Sure pulse is 100 ms IIRC.  The GPS 18x LVC is also 100 
milliseconds, but can be programmed.  Were you thinking rise-time?

Cheers,
David 



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