[time-nuts] Garmin 18x GPS WNRO, revisited

[Rich Wales]

My GPS has been powered down from time to time over the past 10 years.
Its recent WNRO issue was not associated with any power-cycling event.

I am using ntpsec's "SHM" driver (*not* the type-20 NMEA driver), with
the GPS data captured by gpsd.  Gpsd is sensing the PPS signal from the
GPS without difficulty.

I bought a new Garmin 18x LVC recently, btw, and it is running fine on
another computer at my home without any WNRO problems.  I assume the
firmware on the new unit is newer than on my other, 10-year-old GPS, and
that this is why the new GPS is giving good time without my needing to
fudge it in ntpsec.

Rich Wales
richw at richw.org

On 2019-11-29 10:27, David J Taylor via time-nuts wrote:

Thanks for reporting that, Rich.  I haven't seen that issue with either
the GPS18 LVC, or the GPS18x LVC, but neither have been powered down. 
Were yours running continually?  Anyway, I love the fix!

I'm running reference NTP here, and noted that with a type 22 PPS
driver, the "prefer" must include the type 20 NMEA driver.  With the
problem pending, I had hoped that using an e.g. Internet source for
coarse time might have been enough, and had commented out the NMEA
source, but it appears not to be the case.  The PPS was never used (but
it appeared in the billboard).

Cheers,
David