[time-nuts] Thunderbolt reception problems

[Tom Van Baak]

> Hi Tom,
>
> in progress now PRS-10 against a FireFly-IIA...
>
> The PRS-10 is set to a very long time-constant, more than
> 8 hours if I remember correctly.. The Thunderbolt is set to
> 500s TC.

That could be part of the problem. 8 hours seems really long
to me for a PRS10. I mean, it would not surprise me to see
a PRS10 time drift by 10's of ns over 1/3 to 1/2 of a day. So
I wonder what a TC of just 1 hour would look like. A one-day
run using PRS10 alone (no M12 gps) would also settle it one
way or another.

You might also try a run with the TBolt TC = 100s to see if
that makes a difference. The symptom of too large a TC is
excessive wander (because you are giving the OCXO too
much say over the GPS engine).

Sorry if this just makes more work for you. But the matrix
of settings to try and the references to use is bounded. So
even if each run takes a day, you'll have real data within a
week.

Unless you're independently sure of your TBolt OCXO and
your sky/volt/temp/air lab environment, I'd worry some about
a TC that's too long. There's also the issue of the correct
damping factor to match the TC you use. Warren can explain
that better.

/tvb