Icom A6 issues - shocks, interference

On 8/9/2011 7:50 PM, Darryl Ramm wrote:
On 8/9/11 5:07 PM, Eric Greenwell wrote:
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?

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.


Interference from florescent lights is not necessarily a surprise. There
are great LED choices out there.

These are 2' x 4', 3 bulb units (five fixtures total) that fit in a
suspended ceiling (aka "troffers"). None of the other 15 or so two tube,
4' and 8' fixtures in the house cause interference, so I'm wondering if
these new fixtures aren't working properly, or just happen to use very
noisy circuitry. If they are defective I can get them replaced;
otherwise, I'm hoping there is a fix for far less than the LED equivalent!

BTW at least for the house there is a bit more you can do for lightening
protection e.g. see http://www.arrl.org/lightning-protection

We haven't had any problems in the 30+ years we've had a crew radio in
the house, so it's probably not worth doing anything. We rarely have
lightning here, and none of the other glider pilots has reported any
lightning problems.

Its not clear what exactly is going on with your RV. But worth checking
that there is a good ground between the antenna signal ground and
chassis ground. yeas I know you can get a ground loop, but I'd want the
antenna really grounded to the chassis where its mounted, not say having
a ground plane float relative to the chassis.

The antenna is a end fed 3/4 wave (about 2' of 1.5" aluminum tubing, and
4' of whip) with no ground plane and no grounding requirement. It's only
connection is a BNC connector near the bottom of the aluminum tube. The
antenna is mounted on the side of a fiberglass/plywood/foam core
motorhome (no grounding at all, as required by the instructions for it),
using a spring mount to the base of the antenna. About 16' of coax goes
from the antenna BNC to the Icom BNC.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)