In article Eric Greenwell writes:
I recently bought an Icom A6 transceiver for use as a crew radio, and
have discovered several issues with it. Perhaps someone can make
suggestions for improving the situation:

Shocks

My wife was driving the motorhome while I was flying. After about an
hour that included a few transmissions and replies, she got some
tingling, then a shock from the A6. She put it down, and a bit later,
tried it again, with the same result except even stronger. There was
some lightning a few miles away, and some occasional light rain.

The A6 was connected to an external 3/4 wave Rainco antenna, but the
radio was operating on it's own battery and not plugged into the
motorhome battery power. Our previous radio never shocked her in 24
years, but was always plugged into the cigar lighter socket, so I
suspect that might have something to do with it. Has anyone else had
shocks from handheld radios used this way?


As I recall from the description of the antenna, it is a variant of a
j-pole, where the first 1/4 wavelength of the length is actually a quarter
wave impedance transformer in the bottom tube.

As such, it does not need a ground plane or ground at the base to function
as an antenna.

HOWEVER, it does need a ground connection at the base of the antenna tube
to prevent static charge buildup and coupling down to the radio.


You are describing operating a radio connected to the wire coming down from
a lightning rod, where the point concentrates electric field at the top.
Even without lightning, air blowing past it can pick up a static charge
capable of startling a person. (There is also precipitation static in
rain...)

The base of the antenna should be clamped to the metal body of the vehicle,
preferably a solid point (not the sheet aluminum body of a motor home). Be
sure to have a good connection.

While at it, a provision to tip it down flat to not stick up above the
vehicle when lightning is possibly in the area.


Aside from making a mess of your radio, and probably your motor home,
people are killed by lightning.



Interference

We discovered the some new fluorescent lights in the basement ("troffer"
style) cause a lot of static on the A6 when it's used with the external
whip antenna on top of the house. With the lights off, the squelch can
be set to 2; with the lights on, it must be set to 14 or 15 avoid the
static.

The radio is normally plugged into an Icom CP-20 Cigarette lighter
cable, which is plugged into a 12 volt output/120 VAC input bench style
power supply; however, the static and squelch settings are the same when
it's use on it's battery only.

Grounds matter here, too. Be sure the frame of the fixture is well grounded
to the green wire of the circuit. Some modern fixtures won't work at all without
it, so they are leaking something out there.


Alan