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Larry W4CSC
 
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Default Icom 802 troubleshooting

On Fri, 14 Nov 2003 18:35:11 -0800, "David K6DLW"
wrote:

I recently setup one of these for a friend now on his way to Hawaii. I found
that the autotune was turned off as it came from the box. Make sure it is on
or it will not use the tuner. Did the tech say what the SWR was between the
radio and tuner? Was the radio set for full power?

I agree with David. Make sure the display says TUNE not THRU, which
look too similar for comfort. Try it on different frequencies across
the bands, too.

When you press the TUNE button, make sure it tunes, too. If the
display WON'T go into TUNE and you don't hear relays clicking away
madly in the tuner, the problem is the cheap-assed inline connectors
that hook up the control cables. I've had to redo our control plugs,
already, and have raised hell with Icom over this cheapness crap.

I assume you have the AT-140 with the pigtail control cable, right?
If so, get your technician back to the boat and eliminate it before it
strands you. Stupid ICOM, STUPID. Have him take the tuner cover off
and unsolder the control cable pigtail wires from the main PC board.
He can do it very easily as there are soldering loops in the main
board. You can replace the pigtail without taking the main board out
of the tuner. Now, run the control cable through the watertight
fitting and solder the appropriate wires straight to the appropriate 4
solder loops, eliminating this stupid, sure-to-fail board plug made to
corrode. Unfortunately, the one on the radio is still there (same
connector stupidity). Damned Icom Cheapskates. As the boat vibrates
around or something bends the control cable connector against the plug
in the radio, it will open up and have to be tightened inside the
connector again. They're way too fragile! If I have to do ours
again, I'm gonna solder the damned wires together to stop it,
bypassing this plug.

I'd bet your tuner isn't engaging......

Another thing I've noticed on our M802 is RF interference into the
microphone on certain frequencies. It's easy to see. Key the mic and
whistle loudly into it. The LED power output display should all light
up and STAY lit until you stop the whistle. When the RF gets into the
mic jack, you'll whistle and see this display pulsing in power output
as the RF jams the mic circuit with interference. I know it's the mic
circuit because I can wad the coilcord up in my hand and get a good
report and display reading. People on the air will report your audio
is all distorted. You may be experiencing some effects from this RF
feedback problem, too, reducing power output. On our boat, it seems
worse in the lower frequencies, below 4 Mhz. The radio is about 9'
from the tuner at the bottom of the insulated backstay. The
connecting lead from backstay to tuner is about 1' long.

DO NOT MOVE THE TUNER away from the antenna! I don't know where he
got this nonsense, but the tuner needs to be as close to the antenna
as possible. The more ground connections to the ground terminal on
the tuner, the better. Broadcast AM stations with similar antennas
use 36 ground radials laid out around 360 degrees, 1/4 wavelength
long, to get a great ground. On a boat, of course, this isn't
possible. What IS possible and works really great is to use a
trailing ground radial, about 100' long is great. Use insulated wire
sealed at the trailing end to keep the seawater out and as big a guage
as you can. I'm using 120' of #12 bright orange wire with a little
plastic cup on the end as a sort of sea anchor to pull on it as the
boat moves through the water. That holds it out flat very nicely.
The effect is you have created a huge L antenna with the vertical your
insulated backstay (or whip or whatever) and the horizontal part
trailing 120' out behind the boat, with the tuner at the feedpoint.
My ham radio signal reports increase nearly 10 dB with the trailing
ground deployed. Of course, don't forget to reel it in before you
back down or drag it over those obstructions. It works great, also,
at anchor. Ground the tuner to your anchor chain rode with a jumper
cable. The trailing wire will wrap up the anchor in the tide. At the
dock, if you like to play as I do, simply drop a ground wire over the
side and let it lay on the bottom with a sinker to hold it.
Otherwise, Lionheart's tuner is hooked to the engine block below it
with a piece of painted copper flashing from the hardware store.



Larry W4CSC

"Very funny, Scotty! Now, BEAM ME MY CLOTHES! KIRK OUT!"