[ntp:questions] Re: Looking for time sync hardware supported under Linux for under $400?

Richard B. Gilbert rgilbert88 at comcast.net
Tue Jan 17 20:41:07 UTC 2006

Mark Hansen wrote:

> It is possible to find a time synchronization device which is
> supported by the NTP software (NTP version 4.2.0.a on CentOS 4.2)
> for under $400?
> In looking at the various solutions, all I see one units which
> appear to be pretty expensive. Are there less-expensive (perhaps
> GPS-based) units which are supported by NTP?
> For example, I found the InSync GPS Master Clock, shown here:
> <http://www.bytefusion.com/products/ntm/master_clock/gps_master_clock.htm> 
> but it appears to want to use its own Windows-based driver, and I
> don't see it mentioned in the 'Comprehensive list of clock drivers'
> which is included in the documentation for the NTP server.
> Is there anything available in the few-hundred-dollar price range?
> Thanks,

You can get an "FS Oncore" GPS Timing receiver from Synergy Systems 

You should plan to purchase one with the "evaluation kit" unless you are 
equipped to design and produce your own circuit board.  I bought one 
about fourteen months ago when they were still manufactured by Motorola 
and paid about $200 US for it.   It comes with a power supply (wall 
wart) and an antenna.  I've been using it with a Sun Ultra 10 running 
Solaris 8.   It generally synchronizes within a millisecond or less.
sunblok_$ ntpq -p
     remote           refid      st t when poll reach   delay   offset  
*GPS_ONCORE(0)   .GPS.            0 l    4   16  377    0.000    0.001   

There are other GPS receivers that will work quite nicely; one sells for 
around $85 US.   Be certain to get one with a serial (RS-232) interface 
(the USB interface does not work well in timing applications).  Also be 
certain to get a receiver designed for timing applications.  Many GPS 
receivers are designed for navigation and it is generally not possible 
for a receiver to do both timing and navigation well.

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