>
> So whats the answer??? Is it the Aerial, poor squelch or local
interference?
There's something radically wrong with either the antenna, the
receiver, or both. The crudest squelch circuitry shouldn't matter if
all else is OK. If you can't hear ATC in conditions others can or you
know you should by experience, that could be a loss somewhere in your
system of -24dB. What it truly is doesn't matter, and it's one reason
why they speak in nondimensional decibels. To simulate that
same -24dB loss in another way, with a good system, requires you go
out 1500 miles from ATC at sufficient altitude. Even at 1,000 miles
for real-world path loss, something is then very radically wrong.
There's only two things to check. The 360-deg pattern by listening to
a continuous broadcast at a distance where it's weak. Check receiver
performance and coax loss by going up to 4,000, 85nm from a busy
airport. You have to be able to hear the airliners talking to
Approach. That's still 24dB to the good at 85nm assuming 25W
transmitters. Or a small airport at 85nm; you may not hear someone
putting out 2W and not know it, but the math says you have to hear
people with working 8-10W boxes and a few dB of loss in their system
pointed in your direction. In theory, they should be picking up a few
dB with a top mounted antenna.
Reg,
Fred F.
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