Tim,
I have two points. First, the ELT will transmit on 121.5 Mhz, right in the
middle of your comm frequencies. When the antennas are in close proximity, it
will send an extremely high level of power into the receiver. That might fry
it. The solution is to keep the ELT and comm antennas as far apart as is
possible.
Secondly, 90% of the signal is transmitted in the part of the antenna nearest
the feedpoint. The top half of the antenna is there to make it resonant, but
radiates only about 10% of the signal. If you in effect have the majority of
the antenna shielded, then your signal will bounce around the inside of the
plane like inside a microwave oven.
Have you thought about imbedding the antennas into the canopy? It might not be
vertical polarization, but at least it would radiate outside the plane. Just a
thought.
Jim Vance
[email protected]
