[ntp:questions] Re: Please demistify the SHM driver

Jonathan Buzzard jonathan at buzzard.org.uk
Wed Sep 24 21:52:31 UTC 2003


In article <bec993c8.0309240543.72c44459 at posting.google.com>,
	shoppa at trailing-edge.com (Tim Shoppa) writes:
> Paul.Croome at softwareag.com (Paul Croome) wrote in message news:<ea26a3f3.0309240143.50ec6d6c at posting.google.com>...
>> Well... 4.625 is not a very good value for the jitter of a GPS refclock.
>> My GPS (Motorola Oncore) is currently doing:
>> 
>>      remote           refid      st t when poll reach   delay   offset  jitter
>> ==============================================================================
>> *GPS_ONCORE(0)   .GPS.            0 l    9   16  377    0.000   -0.069   0.004
> 
> Apples and Oranges.  GPS_ONCORE is PPS, and he's using a serial-
> attached clock.  4.6ms of jitter isn't great for a serial-attached refclock,
> but it might be the best his clock does over the serial line.
> 

You don't say, I manage better than 4.6ms of jitter with cheapo radio
clocks on the MSF and DCF77 signals.

JAB.

-- 
Jonathan A. Buzzard                 Email: jonathan (at) buzzard.me.uk
Northumberland, United Kingdom.       Tel: +44 1661-832195



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