[time-nuts] WWVB format change in 2012

Tim Shoppa tshoppa at gmail.com
Mon Feb 29 08:31:25 EST 2016


I have observed always less than 1 millisecond offset and skew with the
ntpd wwv audio refclock over more than the past decade.

Setting up the audio refclocks involves calculating and configuring
propagation delay and delays in the receiver and audio chain. As Sanjeev
has mentioned, setting up audio drivers for lowlatency by platform specific
ioctl's is necessary and that may imply code portability issue.

While propagation delay over a several thousand mile path is circa 10ms,
the ionospheric changes are way less than a percent of that. I don't think
it was you Hal, but someone else here was implying uncertainties in
propagation delay on the hundreds of milliseconds, and that is off by 3
orders of magnitude.

(Yes I have heard and observed long path, as well as ionospheric changes in
short path)


Tim N3QE


On Monday, February 29, 2016, Hal Murray <hmurray at megapathdsl.net> wrote:

>
> tic-toc at bodosom.net <javascript:;> said:
> > If you can get audio they work.  The documented accuracy for WWV is
> within 1
> > millisecond of the time pulse.
>
> Where is that documented and/or can anybody verify that they get results in
> that range?
>
> What is the (ballpark) of the day/night shift?
>
>
> --
> These are my opinions.  I hate spam.
>
>
>
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