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

[Bob Camp]

Hi

The tick is a burst of audio at a fairly low frequency. You are going to need pretty
good conditions to get 0.1 ms. The fade process over much of the day will spread 
that out a *lot*.

Bob

> On Feb 24, 2016, at 5:11 PM, Tim Shoppa <tshoppa at gmail.com> wrote:
> 
> 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.
>> 
>> 
>> 
>> _______________________________________________
>> time-nuts mailing list -- time-nuts at febo.com
>> To unsubscribe, go to
>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
>> and follow the instructions there.
>> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.