[ntp:questions] Thunderbolt at NTP ref clock.

David Taylor david-taylor at blueyonder.co.uk.invalid
Thu Aug 1 06:25:06 UTC 2013


On 31/07/2013 20:36, DaveB wrote:
[]
> The server is using 5 'net based servers at this time (my original GPS
> RX died) and is only just stable enough for what I'm doing.  Sometimes
> due to asymetric ping times, it "wanders a bit" for an hour or three.
[]
> Oh...  Though the time server is FreeBSD based, other boxes in my empire
> are a mixture of Windows and Linux, various versions types and
> requirements.
>
> Cheers All.
>
> Dave. (G0WBX/G8KBV)

Dave,

A small GPS with PPS I can recommend to you is this one:

   http://www.adafruit.com/products/746

At least here, on the top floor of a two-storey house in Scotland, it 
gets enough signal to lock consistently.  Not too expensive, and 
available from a UK stockist.

 
http://proto-pic.co.uk/ultimate-gps-breakout-66-channel-w-10-hz-updates-mtk3339-chipset/

A few hundred microseconds should be enough for your pulse, although 
GPSs tend to use either 100 ms or 200 ms by default.  Easier to see on a 
non-storage 'scope as well!  I'm pondering on making a driver and having 
a terminated line running around the shack here (at pseudo RS-232 
levels) for feeding PPS into all my PCs which have COM ports to get the 
best time synchronisation.  AT the moment, those PCs which aren't 
stratum-1 have the poll interval set to 32 seconds to the local 
stratum-1 servers.

I'm sure you know about the information on my site for FreeBSD, Windows 
and Linux, but others may not:

  http://www.satsignal.eu/ntp/index.html
-- 
73,
David GM8ARV
Web: http://www.satsignal.eu



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