[ntp:questions] GPS_NEMA, but high offset and jitter?

David Lord snews at lordynet.org
Thu Feb 25 23:00:29 UTC 2010


Kelsey Cummings wrote:
> Rob wrote:
>> This is normal with NMEA.  You never will get stable time when using
>> an NMEA time source.  For that, you need PPS.  Your PPS is apparently
>> not working.
> 
> It feels like I must be missing something here, running with -d I can 
> confirm that PPS doesn't appear to be working - after enabling flag3 as 
> well.
> 
> 25 Feb 13:53:21 ntpd[75656]: 0.0.0.0 041d 0d kern PPS enabled
> 25 Feb 13:53:21 ntpd[75656]: 0.0.0.0 042d 0d kern PPS no signal
> ..
> 
> Is there any other way to watch the signal to see if it's reaching the 
> serial port correctly?

I've used radioclkd2 to setup my pulse stretcher and pps
ouput pulse length from MSF. I wasn't able to do this with
any accuracy using a scope. Intended purpose is decode of
DCF77 and MSF which it does very well here from both Linux
or NetBSD.

<www.jonatkins.com/page/software/radioclkd2>

David





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