Jonas Grumby wrote:
"Larry" wrote in message
...
jeff wrote in :

So my questions a does lightening often cause this problem? Is it
more likely that a bit of water on the unused external antenna connector
was the real problem? Is it likely my unit is defective? Should I just
assume that I'll always lose GPS at the worst moment? (Yes, I know the
answer to that one!)
....
The system link budget was designed to overcome rain fade. Next time try a
handheld GPS along with your boat mounted GPS and see if they both fade out.
Larry does not account for scattering by the rain droplets, 99% of the GPS
signal is reflected/scattered from rain drops. There is very little
absorption; it's only about 1.5 GHz and the raindrops are very small
compared to a wavelength.

Where is your antenna? Is it under something that can build up some sitting
water during a rain storm?

Is your antenna dc grounded at the center conductor? Charge buildup can
cause front end problems.



The unit has a built-in antenna. It sits under a hardtop with a plastic
window that could accumulate some standing water, but it was not a
torrential downpour (which we were in a few weeks ago without loss) and
the wind would have blown away any large puddles. However, this is
still a possibility. In normal use the GPS locks onto 7 or 8
satellites, so one puddle shouldn't consistently kill it, though there
could have have been enough moisture in the air to attenuate the signals.