[ntp:questions] Garmin 18 LVC high offset and jitter

David J Taylor david-taylor at blueyonder.co.uk.invalid
Mon Sep 19 04:29:36 UTC 2011

> Hi all!
> I am having a problem with a Dell server that has a Garmin 18 LVC 
> attached.
> Can anyone help??
> Thanks!
> Cheers,
> Miguel


I don't know whether it's your problem, but if you are using a Garmin GPS 
18x LVC, be sure to use firmware either 3.20 or before, or 3.70, as there 
is a problem with some versions of the firmware where the NMEA data can be 
more that one second late compared to the PPS pulse, and hence present the 
incorrect time information to NTP.


On Internet servers here I see typical delays of 23 ms upwards, and 
offsets up to 3 ms.


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