[ntp:questions] NTP absolute accuracy?

John Hasler jhasler at newsguy.com
Sun Nov 1 21:11:42 UTC 2009

I wrote:
> Should be as good as WWVB, which is good to within 100usec.  The

David Woolley writes:
> Most receivers only use the slow code (including the simple hardware
> solutions for ntpd).

I'm assuming a real receiver.  With the single-chip designs intended for
"atomic watches" you'll be lucky to get with a second.

> For high accuracy you would have to sync to the carrier, and possibly
> use the fast time codes.

With WWVB I'd use an analog PLL to recover the carrier and a DPLL to get
the PPS.
John Hasler 
jhasler at newsguy.com
Dancing Horse Hill
Elmwood, WI USA

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