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Is the radio getting enough power? A lot of times when we have
various kinds of radio or electronics trouble it's because of
inadequate wiring from the battery to the radio.

"J. Slater" wrote:

Ok. I'm on my 3rd new Icom 402 VHF radio. The first one was exchanged for
extremely poor microphone performance when transmitting with the main unit
mic (as opposed to the Command Mic). You would have to YELL nearly at the
top of your lungs in order for the volume output picked up by all sorts of
VHF's, fixed mounts and handhelds, at all different distances and power
outputs, BUT with the optional command mic, you could talk in a normal tone
and volume and there was no problem!

Second unit was a demo unit, and had a slightly better mic performance,
although not near as good as the original "old" Icom m45 that was in the
boat when purchased. The problem with this radio is that it was having
trouble recieving from some radios, near and far. It was picking up Garmin
Handhelds (models 720 and 725) perfectly yet would not recieve any kind of
transmissions from a couple Hummingbird models, handhelds as well as fixed
mounts. At the same time, my Garmin 725 was picking up the transmissions
from these same Hummingbirds, whilst the Icom was not. Of course it has to
be a problem with my antenna, me thinks. What are the odds of having 2
factory new Icoms screwy? Going step by step with Nigel Calders book, I
test my antenna connections at the radio, all good, climb my mast and
inspect the antenna connections and antenna up top, all "looks" good, the
coax insulation is in great shape, the heat shrink is all intact and tight,
the antenna itself appears as new as when I picked up the vessel three years
prior... I didn't remove the connection at the antenna and do a continuity
or ohm test... but I'm not convinced that my antenna is the problem,
especially when the original Icoms had no problems recieving or transmitting
(just the mic fault on the first 402).

Ok, have I thoroughly lost everyone yet?

The third unit sounds great (voice quality and volume are terrific on all
radios) except that it appears that I can't reach anybody past 5 miles out,
line of sight on the water! Batteries showing 13.6 volts (all were replaced
6 months ago, with new cables, etc.). Radio is connected "directly" to house
battery bank and my voltmeter confirms a full 13.6 volts reaching radio.
Yes, I'm also sure the radio is on "High" power output. I'm also having
trouble picking up transmissions outside of 5 miles as well. Seems to point
towards the antenna again, doesn't it? Antenna height is 58 feet from the
water and it is a 3db model if my memory serves me right.

Is there something obvious that I'm missing here? I just don't really want
to climb my mast anymore times than I have to...

Perplexed Boater.

J.


grandma Rosalie