[time-nuts] Z3801 lockin behaviour

[Tim Shoppa]

Magnus Danielson <cfmd at bredband.net> wrote:
> I haven't really made any real logs. I have checked the EFC values and it does
> move around.

EFC is supposed to move around. Usually it moves around in a nice smooth
fashion, it's the jumps that cause attention!

> > During an EFC jump the TI can go to very large values for short periods
> > of time.
>
> Mine goes into holdover on a regular basis. During holdover it reaches 1.5 us.
> After holdover it tracks in and has TI around 0 (+/- 6-7 ns) but then it starts
> to drift out. It does that with a wobbely walk. It really looks like there is
> too much noise going on so it won't maintain steady lock.
>
> I'm pondering if it may not be something wrong with the running state of the
> SmartClock stuff. Maybe reset that so it has to relearn. I had the same problem
> as I am having now last time I had it powered, and then it didn't sort itself
> out either.  It could also be a bad OCXO. It might be that it needs time to
> heal itself. I didn't have this problem initially thought.

A "virgin" OCXO or one that has been powered up for a long while might
jump around a bit as it outgasses. But there are "bad" OCXO's that
never settle down, and there are "good" ones that after a few years
"go bad".

Tim.