[time-nuts] WWVB format change in 2012
tic-toc at bodosom.net
Mon Feb 29 13:39:19 EST 2016
On Mon, Feb 29, 2016 at 6:35 AM, Hal Murray <hmurray at megapathdsl.net> wrote:
> The audio stuff seems particularly ugly.
> Are there any good non-GPS options these days? In this context, "good" is
> bit hard to pin down. My straw man is either something in production or
> something like a TBolt or Z38xx that is available surplus at hobbyist
On Mon, Feb 29, 2016 at 6:39 AM, Hal Murray <hmurray at megapathdsl.net> wrote:
tic-toc at bodosom.net said:
>> If you can get audio they work. The documented accuracy for WWV is
>> millisecond of the time pulse.
>Where is that documented and/or can anybody verify that they get results in
First off this is a bit time-nuts relevant because RF timing propagation is
germane but the basic pulse extraction is low accuracy and hence not so
much time-nut relevant. That also informs the forest for the trees issue
here: the original intent (as in Dr. Mills PDP-11 assembler coded
demodulator) is a periodic (i.e. daily) clock update. So despite the
predicted 1ms accuracy a .1s system error was probably considered
acceptable. The WWV refclock shares this operational sense with the ACTS
driver. You phone home maybe once a day and, in the case of the ACTS
driver, NTPD won't use it unless you're orphaned.
Regarding non-GPS. Do you consider a CDMA receiver non-GPS? How about a
disciplined oscillator in hold-over? In consideration of the recent GPS
glitch is GLONASS non-GPS or are you speaking more broadly (ie. GPS as a
synonym for GNSS).
And lastly despite the politics it would seem the folks on the
ntp-questions and ntp-hackers are a better resource. Unless they're all
More information about the time-nuts