[ntp:questions] Maximum time2 fudge value for NMEA refclock?

Terje Mathisen "terje.mathisen at tmsw.no" at ntp.org
Sun Jul 25 21:08:01 UTC 2010


David J Taylor wrote:
> "Terje Mathisen" <"terje.mathisen at tmsw.no"> wrote in message
> news:5dbth7-6k8.ln1 at ntp.tmsw.no...
> []
>> 55401 183.702 127.127.20.0
>> $GPGGA,000303,5955.1025,N,01038.4599,E,2,06,2.0,33.1,M,39.8,M,,*77
>>
>> Yes, that is the location of the metal bracket on the east end of my
>> roof. :-)
>>
>> Terje
>
> 59.918375N 10.6409983E
>
> So that's in the western suburbs of Oslo? Looks more like the north edge
> of the roof on Google Earth!

Well, it is really the NE edge. :-)

I also have another antenna placed on the opposite side, which I use to 
connect up any of my other GPSs when I want very good visibility.

 > My wife is in Trondheim at the moment, and
> having better weather, I think!
>
> http://romeo.skybert.no/trondheim/k3/cam4_image.jpg

Yes, the low pressure area over Sweden which was supposed to pass us by 
turned a little bit more west last night, so that the edges of it hit us.
>
> Interestingly, on my own FreeBSD system I have no time offset fudge:
>
> server 127.127.20.1 mode 0 minpoll 4 maxpoll 4 prefer
> fudge 127.127.20.1 flag1 1 flag3 1 refid PPS

My setup works without the fudge, I just wanted to make the initial sync 
a little faster: Without it it first syncs to NMEA, then has to 
slew/step 300 ms in order to lock on the PPS signal.

OTOH, this seems to depend on exact OS and NTP version numbers, I 
haven't needed the same tweaks previously...

Terje

-- 
- <Terje.Mathisen at tmsw.no>
"almost all programming can be viewed as an exercise in caching"




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