Garmin GpsMap 396 - Flight Test #2

"Mike Spera" wrote in message
ink.net...


I'm sorry to say, it sounds like you have an EMI issue. If you key the
mic and the sats drop, that's a pretty good indication of at least one
problem.

Upgrading the software to the latest code should go without saying.
Garmin will insist that you do that before they will help you
troubleshoot such an issue. Garmin did make GPS reception improvements
in some later software releases.

O.K., if there is an EMI issue, why does it only affect the Garmin? The
Lowrance and Apollo units were completely unphased by the transmissions
and never lost their lock during the entire test flight (and the previous
8 years of use). I tested them all side by side. The Garmin sat bars were
hopping all around in straight and level flight while the older units were
stone solid.

Something specific to newer GPS receivers?

Thanks,

Mike

Hi Mike,

did you try the "almanac" fix as suggested by Dan?

I inquired to Garmin Tech support about our problems and got the
following response about clearing the almanac. Probably worth a shot.

--Dan


========================
Problem:
I had a problem with satellite reception over the weekend. In
disucssing this with other GPSMAP 396 users, including one who recently
upgraded to firmware 3.20, it seems they are experiencing similar
problems as well.
(i.e. intermittent GPS satellite loss) I have a GPSMAP 195 and have
never had a satellite signal issue. Is this a known problem? Will there
be a firmware fix?
===============================
Thank you for contacting Garmin.

As the GPS uses a satellite almanac of data to track the satellites,
corruption of this almanac will cause the unit to drop the satellite
signals. To correct(erase) the almanac, turn the unit off. Press and
hold the OUT button while turning the GPS on. When the GPS powers on,
release the buttons and let it acquire the satellite signals to start
rebuilding the almanac.

If you have any other questions, please let me know.

Best Regards