[time-nuts] Z3801 lockin behaviour

[Tim Shoppa]

Magnus Danielson <cfmd at bredband.net> wrote:
> > If it doesn't lock after a few hours, I'd suggest a full
> > reset. Also check your signal levels, and elevation
> > mask. Did it get your lat/lon/alt correct?
>
> Seems alright. Get SS values which seems good, occassionally above 200 but
> rarely below 100. Usually track 5-6 satelites but if it had been a 12 channel
> receiver I would have had 12 satellites tracked over the 10 degree elevation
> mask.

Your GPS part seems to be working fine.

Have you logged the EFC values before/during/after unlock? Some Z3801A's
have OCXO's that are remarkably steady with nice smooth EFC curves and
hardly ever a jump, others jump around by hundreds or thousands of EFC
units a few times a year, and others jump around by hundreds or thousands
of EFC units multiple times a day (going out of lock at each jump.)

During an EFC jump the TI can go to very large values for short periods
of time.

Tim.