[time-nuts] Using a Vectron OCXO 5mhz oscilator with ntpd

[michael taylor]

On Dec 11, 2007 11:19 PM, Todd Eddy <vr at vrillusions.com> wrote:
>
> My thought was using the ntp servers for that, since that will get the
> signal withing a couple msecs of the time, then use the pps output to
> get it even more accurate from there.  Kinda like one of the ways to
> interface with the gps receiver that it only gets the PPS signal and not
> the time.  Kinda ugly, but you got to start somewhere.  I'll probably
> end up getting a gps receiver since there's lots of documentation on
> that and I can mess with it at home, or maybe convince work to let me
> drill a hole in the roof :)  Thanks the much simpler diagram though.

For the accuracy of a NTP public server, using a TAPR Clock Block (or
RefLock II, www.tapr.org)  with a OCXO or TCXO is likely as much
modification as may be usefully necessary for a public
(Internet-facing) NTP server. I'm not sure of how much accuracy and/or
precision you care about. Is to within 2 milliseconds good enough?

See:  John Ackermann's "Is This the World's Most Accurate NTP Server
Hardware?" <http://www.febo.com/time-freq/ntp/soekris/>

I'd consider getting a Timing GPS receiver such as the iLotus "M12M
Timing", available from Synergy Systems, or the Trimble "Resolution T"
module. If only for your "house reference" to evaluate your attempts.
Older Motorola OnCore GPS modules are often cheap on eBay, look for
the timing versions.

-Michael