[ntp:questions] Re: WWVB 60kHz Receiver
Richard B. Gilbert
rgilbert88 at comcast.net
Sat Apr 15 13:33:49 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.
WWVB Receivers are occasionally available on e-Bay for $100 - $300.
> 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?
Possible? Yes. Probable? No! If you want to invest about $35 in an
"atomic clock" You can hang it on your wall and check the reception
indication several times during the work day. If you get solid
reception during daylight hours a WWVB receiver just might give you
sub-millisecond accuracy. If you lose signal during daylight hours,
> 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.
I never had a WWVB receiver to try it with. If someone wants to lend me
some equipment I'll compare it with my GPS refclock.
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