[time-nuts] Ublox F9P multi-band GPS receiver

[Poul-Henning Kamp]

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In message <73DB44DE-F81E-4A3C-B27A-C9875DA91120 at n1k.org>, Bob kb8tq writes:

>Once you do replace the TCXO, you then are very dependent on a sawtooth correction 
>to run your GPSDO. The PPS becomes one big long hanging bridge and thus is not useful. 

Well...

If you do not have the sawtooth, what you can do instead is try to steer your
external clock to give you *maximum* jitter on the PPS.

That situation arises when you get the GPS to "waffle" between which
two clock-cycles of the external clock it should put the PPS.

It is incredibly dependent on the GPS receiver internals, and it is
very hard to keep stable, but you _can_ do it.

I know, because I did :-)

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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