[time-nuts] Next step up from basic GPS/PPS timekeeping

Tim Shoppa tshoppa at gmail.com
Wed Feb 24 17:11:12 EST 2016


Hal -
  In my experience over more than a decade, the ntpd WWV audio refclock has
jitter circa 0.1ms.

  This is not nanosecond-time-nut PPS territory. But it is more than good
enough for WAN ntpd.

  I use a Ten-Tec RX-320 as a cheap frequency-agile receiver for WWV. In
between 5MHz/10MHz/15MHz usually one or two bands are open from me to
Colorado.

  On the subject of WWVB - if you are near Colorado then you can have 24x7
reachability, day or night. For me on the east coast, WWVB 60kHz is
reliable in darkness but not in daylight.

Tim.

On Wed, Feb 24, 2016 at 1:56 PM, Hal Murray <hmurray at megapathdsl.net> wrote:

>
> tshoppa at gmail.com said:
> > My opinion if you want to serve reliable time through a longer GPS
> outage:
> > add a WWV or WWVB based radio clock. e.g. a shortwave radio and https://
> > www.eecis.udel.edu/~mills/ntp/html/drivers/driver36.html
>
> Do you have any graphs comparing WWV or WWVB to GPS when your GPS is
> working
> correctly?
>
> When I run out of other things on my list, I'd like to collect that data.
> What receivers do people recommend?
>
> I have one of the low cost WWVB receiver modules but I never got any useful
> data out of it.  Maybe it's time to try again.  It might work better on the
> end of a long cable to get it away from all the EMI in my office.
>
>
> --
> These are my opinions.  I hate spam.
>
>
>
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