[ntp:questions] Garmin GPS18x LVC problem since firmware 3.50

David J Taylor david-taylor at blueyonder.co.uk.invalid
Tue Dec 28 22:34:36 UTC 2010


Following my previous message, I can confirm that the NMEA output from the 
GPS18x LVC with the firmware 3.50 upgrade is coming out something like a 
second after the PPS signal, and worse, it's very variable so sometimes 
just before the PPS leading edge, and sometimes after.  No wonder NTP is 

I have contacted Garmin UK via the Web/e-mail form, but as it's almost a 
two-week holiday here, if someone has a better contact with Garmin US it 
might be worth alerting them as well.  I have requested that the firmware 
be fixed so that the NMEA output be well under one second delayed, and 
that the delay be more reproducible (although I haven't made that point 
strongly enough, so it should be emphasised).

Can NTP even handle an offset of more than one second between PPS and 

Thanks to Dave Hart for pointing out:

I felt it best to start a new topic for this problem.


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