[ntp:questions] Tobit LAN!Time DCF77 receiver not working

David Lord snews at lordynet.org
Fri Dec 25 11:34:44 UTC 2009


Marc-Andre Alpers wrote:
> Es schrieb David Lord:
> 
>> I've fudged the SHM with
>> "fudge 127.127.28.0 time1 0.024550 refid MSFa"
> 
> I'm about 400km away from DCF77. What a fudge should I use?
> 
> Actuell ntpq -p from over night running PC.
> 
>      remote           refid      st t when poll reach   delay   offset  jitter
> ==============================================================================
>  LOCAL(0)        .LOCL.          10 l   56   64  377    0.000    0.000   0.001
> *SHM(0)          .DCF.            0 l   19   64  377    0.000    0.390   0.264
>  europium.canoni 193.79.237.14    2 u  901 1024  377   52.403  -24.525   1.784
>  s1.uruz.org     82.96.64.2       2 u  886 1024  377   41.949   -7.581   1.797
>  sun.raveisking. 244.194.111.255  3 u  899 1024  377   32.239   16.241  13.018
>  simbx01.sixxs.n 5.60.127.116     2 u  913 1024  377   53.695  -66.847  19.488
> 

Unfortunately those sources don't give you a meaningful
indication as all too far away from each other. As I said
before a GPS to serial port is easiest for calibration.
Propagation delay is short compared to other hardware
factors which aren't easy to estimate. Either bring a
reference in or take your kit to where there's a better
reference or accept what you have now (which looks more
likely to be consistent than your network sources).


David




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