Sounds suspiciously like ignition noise to me. You might want to tell us
what kind of aerocraft this is.

Jim

--
"It is the mark of an educated mind to be able to entertain a thought
without accepting it."
--Aristotle


"Bob" wrote in message
...
Com Icom A-6 handheld connected only to headset, NO CONNECTION TO A/C
ELECTRICAL. Static noise and flickering RX symbol on handheld (no
voice being received)so distractiing its makes use unbearable. No
static during actual voice reception-tower reports clear,good, no
noise voice. Outside of a/c facing prop or tail (no noise)-move in
circle about a/c noise develops. Inside a/c noise at all times except
during actual voice reception. The following have NO affect: tried
different radio,headset, partchcords-disconnected alternator
belt,field lead-put condensor for noise trap on regulator,coil,
distributor-on/off of elec T/B(has in-line filter),trim
tab,intercom,strobe,elec tach to - coil post,all electrical
connections,wires,terminal strips verified good-only other electrical
are the amp/vot meter connections. Noise does not occur when radio/
headset combo used in other a/c. Noise cancelled out at squelch level
20 and high volume. 12 years building, FAA certified, l year so far
chasing "BUGS" and hopefully last item to correct so I CAN FLY!
P LEASE HELP IF YOU WOULD
Thank You,