[ntp:questions] Re: questions on msf (via shm) clock

mike michael.no.spam.cook at wanadoo.fr
Wed Dec 29 23:47:51 UTC 2004


dave morgan wrote:
> Hi,
>   after a couple of false starts (transistor back to front,
> resistor connected to wrong pins :-/ ) I have got my MSF refclock
> working. This has raised the following questions -
> 
> a) will its jitter figure never go below 1?

   you may be able to get better a bit better. I have a homemade
DCF refclock that get around 1 aswell. For the $15 it cost to make
I consider it OK.
      remote    refid      st t when poll reach   delay   offset  jitter
==============================================================================
  127.127.1.0   LOCAL(0)   10 l   32   64  377    0.000    0.000   0.001
*127.127.28.0  .DCF.       0 l   34   64  377    0.000   -3.387   1.115

> 
> b) why does the refid for this clock show SHM(0), even though the 
> lines for it in the ntp.conf file is as follows?
> 
> #msf rx on serial port 1
> server 127.127.28.0 prefer

   .0 is shm(0) .1 (1) etc

> fudge 127.127.28.0 stratum 2  time1 0.022  refid MSF
> 
> c) what stratum should I declare it? I have left it fudged to 2 for
> now as the jitter seems no better than the other stratum 2 servers
> I use.
> 
   As it is a reference , I leave mine at the default of 0 . The stratum
is just how may steps you are away from from the reference, it doesn't
directly relate to the accuracy or stability as far as I am aware.
> 
$ ntptrace stratum1.d2g.com
stratum1.d2g.com: stratum 1, offset -0.003002, root distance 0.000000, 
refid 'DCF'

> 
> best regards
> Dave Morgan
> 



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