I've had an Icom 802 SSB with AT140 tuner installed on the boat for
over 4 years now. It uses the more or less standard 23 ft whip
antenna and has the same ground system that the old SSB had which is
alleged to be a copper strap running down to the bonding system. It
has worked fairly well up until recently but now seems to be
transmitting weakly and the control panel is indicating a high SWR.
Nothing has changed as far as I can determine and all connections seem
to be tight and corrosion free. I'm suspecting that the tuner is not
working properly but other than buying and installing a new AT140, I
can't think of any way to trouble shoot this issue.

Any suggestions?

In article ,
Wayne.B wrote:

I've had an Icom 802 SSB with AT140 tuner installed on the boat for
over 4 years now. It uses the more or less standard 23 ft whip
antenna and has the same ground system that the old SSB had which is
alleged to be a copper strap running down to the bonding system. It
has worked fairly well up until recently but now seems to be
transmitting weakly and the control panel is indicating a high SWR.
Nothing has changed as far as I can determine and all connections seem
to be tight and corrosion free. I'm suspecting that the tuner is not
working properly but other than buying and installing a new AT140, I
can't think of any way to trouble shoot this issue.

Any suggestions?

When you hit the Tune Button, on the radio, do you hear the Autotuner
relays clicking as the tuner does it's thing? If Yes, then suspect the
RF Ground. If No, then open the tuner, and see if it is still powered by
the radio +12 Vdc buss. Yu can also check the coax cable between the
radio, and tuner, by putting a dummy load, at the tuner, and a SWR or
Wattmeter at the radio, and see if the coax is degraded.

--
Bruce in alaska
add path after fast to reply

On Thu, 20 Aug 2009 09:39:44 -0800, Bruce in alaska
wrote:

When you hit the Tune Button, on the radio, do you hear the Autotuner
relays clicking as the tuner does it's thing? If Yes, then suspect the
RF Ground. If No, then open the tuner, and see if it is still powered by
the radio +12 Vdc bus.

Sounds like a plan. No, I have not heard the tuner relays recently
which is one of the things that makes me suspect a tuner problem. Is
there a test point for +12 readily available inside the tuner box?

If the +12 is there (or not), what next?

Wayne.B wrote in
:

I've had an Icom 802 SSB with AT140 tuner installed on the boat for
over 4 years now. It uses the more or less standard 23 ft whip
antenna and has the same ground system that the old SSB had which is
alleged to be a copper strap running down to the bonding system. It
has worked fairly well up until recently but now seems to be
transmitting weakly and the control panel is indicating a high SWR.
Nothing has changed as far as I can determine and all connections seem
to be tight and corrosion free. I'm suspecting that the tuner is not
working properly but other than buying and installing a new AT140, I
can't think of any way to trouble shoot this issue.

Any suggestions?


A 23' whip is resonant on:

234/Mhz = feet for a 1/4 wave antenna.

234/23' = 10.17 Mhz or something close to that.

As you approach this frequency, no tuner is really required so press the
button to bypass the tuner, taking it out of the circuit.

You can make the M802 transmit on any frequency between 2 and 30 Mhz.
Hee hee....I found my post from 3/2008 when I looked for the commands:

To open up the transmitter so it will transmit on ANY frequency from 2-
30
Mhz, simply hold down the MODE and TX buttons with the M800 powered off,
then, while holding these buttons down, turn it on and it will toggle
into
full width transmit mode. To put it back into marine channels ONLY just
repeat the procedure.

After opening up the transmitter so you can transmit anywhere, tune the
radio in the Mhz mode to 10.17 Mhz and see if it tells you the SWR is
very high when you key the mic and whistle into it so you produce RF
output on the SSB radio. Can you hear static and WWV on 10.000 Mhz
well? If not, the antenna isn't connected to the radio, somewhere.

If reception is not good around 10 Mhz, with the tuner bypassed, the
tuner isn't the trouble, probably. Bypass the coax cable laying in the
bilgewater with a new piece between the tuner and radio just laying on
the deck. Did that fix it?...bad coax.

If you still suspect the tuner, you can make up a coax cable with the
PL-259 connector for the radio on one end and just wires on the other.
Disconnect the tuner from the whip and connect the coax center conductor
directly to the 23' whip's feed point. Connect the shield to what you
think is the tuner ground strap, which, I assume, you've already
inspected for corrosion, good connections, open circuits. The whip
should work directly connected to the radio at some point around 10.17
Mhz, give or take half a megahertz. There should be a broad (in
frequency) drop in SWR near the antenna's natural resonant point around
10 Mhz. If there's not, hooked directly up with new coax bypassing the
whole normal feed system....the little conductor inside the 23' whip has
parted and is open.....or the ground system isn't there. Drop an anchor
over the side and let it almost touch the bottom on CHAIN rode. Use a
vice grip to clamp the shield of your coax to the chain at the base of
the 23' whip, making a SUPERGROUND in seawater for it. Test it again.
If you find the broad low SWR around 10 Mhz, the antenna is fine, the
boat's ground is crap. Anchor chain is nearly the perfect radio ground,
even all rusty like that, because it's so massive soaked in seawater.

Store that info away for emergencies, too. When you're using SSB and
they can't hear you, drop the anchor and hook it to the tuner ground and
your signal will double, almost every time. You'll have to RETUNE the
tuner to get a new tuning solution, though.

Hope this helps you find it. M802 is a nice radio but stupidly packaged
with its case left open so the sea air can get inside sucked in by the
fan to cool it and corrode the hell out of everything
inside...eventually. Icom knows better because the M602 is SEALED with
an external heat sink....\

================================================== =================

Oh, one more touch.....Icom made the stupidest decision putting a
pigtail with an open, unsealed cheap connector OUTSIDE the sealed tuner
to plug the control cable into. This is just WRONG! It'll corrode,
idiots! If this has happened to your installation, the tuner isn't
working and the SWR will stay high all over the place.

To correct this problem, unscrew the cover on the AT tuner and carefully
remove it without ripping the seal. Notice where this stupid pigtail
nonsense is soldered to the main tuner PC board on little solder loops
sticking up from the board. UNsolder the pigtail and cut the stupid
open plug/socket off the control cable. Throw the pigtail and
connectors overboard, just to show Icom you mean business. (We had a
ceremony, complete with Davy Jones, who was drunk as usual.) Now, feed
the control wire cable through the watertight connector after loosening
up the compression nut and tighten it down to seal it back up against
water intrusion. Skin back the insulation and solder the wires NOTING
THE SAME COLOR CODE CONNECTIONS AS THE PIGTAIL, directly to the solder
loops on the PC board inside the tuner. Problem solved. AT-140 will
last until the lightning hits it, now. Unsolder the wires to replace
it...not rocket science.
--
Larry

If that doesn't work, bring the boat to Charleston and I'll perform
magic on it. They all stood in awe around the speaker when the 3rd ham
station I contacted from right inside the crowded marina was in New
Zealand from the insulated backstay hooked up to the insulated triattic
between the masts on Lionheart...(c; We were on 20 meter ham band.

73 DE W4CSC/MM2

Bruce in alaska wrote in news:fast-D8B928.09394320082009
@unknown.usenetserver.com:

Yu can also check the coax cable between the
radio, and tuner, by putting a dummy load,

Dummy load? Oh, yeah, the 80M dipole over the back yard....(c;]


--
Larry
W4CSC

In article ,
Wayne.B wrote:

On Thu, 20 Aug 2009 09:39:44 -0800, Bruce in alaska
wrote:

When you hit the Tune Button, on the radio, do you hear the Autotuner
relays clicking as the tuner does it's thing? If Yes, then suspect the
RF Ground. If No, then open the tuner, and see if it is still powered by
the radio +12 Vdc bus.

Sounds like a plan. No, I have not heard the tuner relays recently
which is one of the things that makes me suspect a tuner problem. Is
there a test point for +12 readily available inside the tuner box?

If the +12 is there (or not), what next?

If the +12 Vdc is there and the tuner doesn't tune, then you gots a
tuner problem. I would unhook the Tuner, All the wires, and let it sit
for a minute, then reconnect it, and recycle the Main Power to the
radio, just to be certain that you have reset the Brains in both the
radio and tuner, and then try things again. If things don't start
working you gots yourself a DEAD Tuner, and it will need Icom Service,
most likely..... I suppose one could dig into it, but the thing is
Microprocessor Controlled, and without a Logic Analyzer, it could get
messy really quick.

--
Bruce in alaska
add path after fast to reply

On Fri, 21 Aug 2009 11:33:20 -0800, Bruce in alaska
wrote:

If the +12 Vdc is there and the tuner doesn't tune, then you gots a
tuner problem. I would unhook the Tuner, All the wires, and let it sit
for a minute, then reconnect it, and recycle the Main Power to the
radio, just to be certain that you have reset the Brains in both the
radio and tuner, and then try things again. If things don't start
working you gots yourself a DEAD Tuner, and it will need Icom Service,
most likely..... I suppose one could dig into it, but the thing is
Microprocessor Controlled, and without a Logic Analyzer, it could get
messy really quick.

Thanks, I'll give it a try.

The problem could be a number of things. Perform a continuity check
on your coax cable and the 4-conductor control cable. When you press
the tune button a brief start signal is sent to the tuner via the
white wire of the 4-conductor cable. The tuner then puts the radio
into transmit, via the green wire, with a 10 watt cw signal. You
should see the TX icon on the 802 display. If the tuner detects the 10
watt signal, it will initiate a tune cycle. The TUNE icon will flash
and you should hear a buzzing sound from the tuner. If the display
immediately shows the THRU icon after pressing TUNE, the tuner is not
working. There is really no reason to "open" your radio to transmit on
any frequency unless you want to operate on the ham bands. However if
you insist, the procedure given was wrong. You must press and hold the
2, MODE, and TX buttons and then turn the radio on. If you do decide
to open the tuner, be advised that there are nuts and lockwashers
behind each of the 10 screws holding the cover on. Even if there is no
antenna or ground whatsoever, the tuner will still try to tune and you
should hear the buzzing sound of the relays.

Eric

On Thu, 20 Aug 2009 11:56:33 -0400, Wayne.B
wrote:

I've had an Icom 802 SSB with AT140 tuner installed on the boat for
over 4 years now. It uses the more or less standard 23 ft whip
antenna and has the same ground system that the old SSB had which is
alleged to be a copper strap running down to the bonding system. It
has worked fairly well up until recently but now seems to be
transmitting weakly and the control panel is indicating a high SWR.
Nothing has changed as far as I can determine and all connections seem
to be tight and corrosion free. I'm suspecting that the tuner is not
working properly but other than buying and installing a new AT140, I
can't think of any way to trouble shoot this issue.

Any suggestions?

Followup:

After trying all of the helpful suggestions here, and talking to a
number of people, the SSB was still not transmitting. Apparently
there are no longer any SSB tech guys in this area and bringing
someone over from Ft Lauderdale was going to cost a bundle. Gary
Jensen at Dockside Radio in Punta Gorda suggested buying a dummy load
and a Wattmeter/SWR Bridge to test definitively whether or not the
transmitter was working. That seemed like a reasonable suggestion
since MFJ Electronics has a good selection at reasonable prices.
Everything arrived today and I hooked up the wattmeter and dummy load
just before the antenna tuner, started a calling sequence with Winlink
and checked the meter. Everything looked good with over 100 watts
showing and the dummy load was heating up. It looked like it must be
a tuner problem since I'd already checked the antenna and ground as
best I could. To make a long story short I removed the test
equipment, hooked everything back up the way it was, and tried yet
another test transmission. This time everything worked OK and I was
able to contact several different Winlink gateways and check into The
Maritime Mobile Net. Apparently there had either been a bad
connection at the point where I inserted the wattmeter, or the
presence of all that official looking test equipment scared the radio
into performing properly. It looks like I'll need to carry the test
gear around when we go cruising from now on. Both the meter and
dummy load are good up to 200 MHz so they can also be used to test the
VHF radios if need be.

Wayne.B wrote in
:

On Fri, 21 Aug 2009 11:33:20 -0800, Bruce in alaska
wrote:

If the +12 Vdc is there and the tuner doesn't tune, then you gots a
tuner problem. I would unhook the Tuner, All the wires, and let it sit
for a minute, then reconnect it, and recycle the Main Power to the
radio, just to be certain that you have reset the Brains in both the
radio and tuner, and then try things again. If things don't start
working you gots yourself a DEAD Tuner, and it will need Icom Service,
most likely..... I suppose one could dig into it, but the thing is
Microprocessor Controlled, and without a Logic Analyzer, it could get
messy really quick.

Thanks, I'll give it a try.



Wayne, what did you find out about the M802 problemo?



--
"iPad is to computing what Etch-A-Sketch is to art!"

Larry