>What are the 2 frequencies that you cited? It is highly unlikely
>you're transmitting poorly on only one freq, as any modern comm uses
>digital frequency synthesis tied to a single reference freq. But at
>the extreme ends of the band, both antennas and tuned sections of
>comms can fall off markedly in performance. To be unreadable at 3
>miles, though, it may take a bit both problems (compromise in the
>Archer's location and mistuning in the comm).
>
>The effect would just weak signal, but if garbled, your Europa may
>have a nearby VHF antenna or metal piece of just the right size
>causing "re-radiation" only at certain freq's. Or maybe this problem,
>compounded by the above.
>
>A crude comm tester is a handheld comm, in hands of a buddy at some
>distance, with a lousy receiving antenna, such as a stretched out
>paper clip in place of the ducky. You want enough noise in the
>received transmission to gauge signal strength and still hear any
>garbling in the audio. Xmit up the band at whole or half mHz points
>ans see what happens.
I've seen some posts suggesting frequency sensitivity (not likely)
and coax routing (less likely). The strongest influence on antenna
performance that yields large differences from one instance to the
next is radiation pattern. You can easily confirm your antennas
gross performance by tuning in a weak station from some lofty perch
and ask them to transmit continuously while you do a flat (rudder
only) 360 degree turn. If their signal drops markedly in the headsets
with some particular orientation to your airplane in receive, you can
expect a similar degradation for transmit in the same direction.
>Regards,
>Fred Fillinger, A063
>
>Barry Tennant wrote:
> >
> > Hi all you radio experts out there.
> > I have a particularly annoying problem with my Becker radio and Bob
> > Archer antenna.
> >
> > I have one local airfied (one frequency) that always cannot hear me when
> > I try to land. I thought that my radio was broken the first time but
> > last week I was there and tried to call them as close as 3 miles and
> > they reported that I was unreadable. I immediately called up my home
> > field which was 30 NM away for a radio check and was reported reception
> > 5.
Bob . . .
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( I have more respect for the fellow with a )
( single idea who gets there than for the )
( fellow with a thousand ideas who does )
( nothing.. )
( Thomas A. Edison )
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