[ntp:questions] Re: WWVB 60kHz Receiver

Ry malayter at gmail.com
Sat Apr 15 06:14:42 UTC 2006


Speaking of WWVB clocks: does any company actually manufacture a
preconfigured WWVB clock with a serial interface anymore? I've been
unable to find one. Spectracom and the other manufacturers that used to
make them seem to have switched over to GPS entirely.

The reason I ask is I'd like to set up a refclock at my employer's HQ,
but the datacenter is in the 10th floor of a 50-floor high rise. The
building is closely surrounded by others with similar or greater
height. I can't use GPS becuase none of the windows open, renting roof
space is not possible, and I cannot get any GPS signal through the
windows. The location is basically the worst "urban canyon" scenario
you can imagine .

I'm 1462.5 km (4.8 ms) from the WWVB transmitters, which is well inside
the coverage area maps on the NIST site. I figure WWVB is my best
(only?) option for a refclock at this location. Is sub-milisecond
accuracy possible using a WWVB refclock? The NIST site says 0.1 to 15
ms phase error, which is two orders of magnitude. I see ~5 ms average
offsets when I sync with nearby stratum-1 servers via NTP. Would WWVB
perform any better?

I'd rather not build a WWVB receiver and antenna if I can just buy one
for use with NTP.




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