View Single Post
  #11   Report Post  
Keith
 
Posts: n/a
Default Icom 802 troubleshooting

The antenna base is about 3' away from the tuner at it's present location,
on the flying bridge. They are basically at the same level. The antenna lead
exits the locker, then runs perpendicular about 2' to the antenna hookup.

Going to tackle the problems one at a time. Turns out that the early 802's
had manufacturing problems, and won't transmit at a strong power level. I
have one of these, and am sending it back to the factory for warranty
repair. That's what I get for being an early adopter! Next, I really suspect
the control cable, so will double check and verify that.

The tuner placement seems to be anything but a concensus. I hate to move the
thing, but if all else fails, that will be the final change. I can place it
in a locker about halfway between the antenna and ground plate. In that
position, the ground foil would have to go about 5' to the ground plate. The
other place would be right in the engine room on the bulkhead, about 2' to
the ground plate, but I worry more about heat, etc. in there. Will keep
everyone posted, and thanks for the help!

"Wayne.B" wrote in message
...
Keith,

I'm trying to visualize where the base of your antenna is. Ideally
the tuner should be mounted at or below the base. If the tuner is on
the flybridge and the base is down near deck level, then your antenna
feed is running down, and more or less parallel to the antenna itself.
If so, this may be the source of your problem.

On the other hand, if the antenna base is on the fly bridge near the
antenna tuner, it should be OK assuming a good ground and proper hook
up with the tuner control cable.

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

On Sun, 16 Nov 2003 19:37:04 -0600, "Keith"
wrote:

OK, let's see if I can give feedback to all of your notes.

Yes, the radio is set to "tune", and on full power. I will double check

to
make sure the tech didn't change either of the settings. I do not know

what
the SWR's were. The bad part was that I had been trying to hook up with

this
guy for awhile... and I wasn't here when he did the checks.

When I hit "tune", I sure don't hear any clicks or any other evidence

that
it's doing anything. The control cable was the one thing I DIDN'T do

myself,
so I'm beginning to suspect that as Larry pointed out. I remember that

topic
on here before. The little pins were so tiny I couldn't hardly see them

much
less solder them! I think I'll work on this as Larry suggests.

The Antenna is a Digital fiberglass... don't remember the exact length,

but
what the folks around here recommended... The boat is fiberglass, a

Krogen
42. The 2" copper foil runs about 12-15' from the tuner on the flying

bridge
down to a big Wunderbar (sp?). The bar is a scintered bronze plate, about
24" x 6" or so. Nothing else is connected or grounded to this, except

that I
also have a 2" foil strip that runs to the radio and connects to the

ground
on the back, as shown in in ICOM installation manual.

I think I'm going to redo the control cable as Larry suggests, and go

from
there.

"Bruce in Alaska" wrote in message
...
In article ,
"Keith" wrote:

Well, I had a tech come out and check out my system. M-802 with the
automatic antenna tuner. He said that the radio is only putting out

about 50
watts, and should be putting out 100-150 watts, so he thinks

something
is
wrong with the radio (new, right outta the box...)

He also mentioned that the automatic antenna tuner should be closer

to
the
ground plate. In the Icom manuals, they said to mount it as close to

the
antenna as possible, so it's on the flying bridge, and the conductor

from
the tuner to the antenna is about 3'. I can move it about halfway

between
the antenna and the ground plate in the engine room. Who's right?

The final thing is that I ran a 2" ground foil strip from the radio

to
the
ground plate as well, as required by the ICOM manual... he said this

isn't
necessary and should be disconnected. I'm really confused now.

Help!

At this point, I'm going to take the radio in to the dealer and have

it
checked out and anything corrected as needed, then see how things

work
before I start moving the tuner around.



Hello Keith,


I don't know the guy you hired to do your HF Radio work, but from the
sounds of things, he isn't one of the greatest Tech's to walk down the
dock. First thing, is to transmit into a Dummy Load, and see if the
radio is capable of putting out it's rated power, into a perfect

antenna.
If yes, the problem isn't in the radio. If no, then the radio needs to
be realigned. (tuned) Second, understand that any SSB Radio maybe
transmitting rated power, and it doesn't nessesarily show up on a
non-peak reading Wattmeter. There are many reasons to have the
autotuner mounted at this polace or that place. Most are related to
what type of RF Ground System your vessel has. From a strictly RF
standopoint, closer to the Ground Plate is better, and 2" copper foil
is minimal for any connection to a RF Ground System. what is the

length
of the copper foil in feet? The longer the foil, the worse the ground
impedance will be, and the harder the tuner will have to work to tune
the antenna. You don't tell us anything about the vessel construction,
RF Ground System, or antenna system. Knoing these would be critical
in advising you on your installation.
Points of interest.
1. If your foil is longer than 3 or 4 Feet, then what you are asking
that autotuner to do the almost impossible. Think it as if the tuner
wan't sitting at ground but at some point above ground and that point

is
the length of the copper foil. Lets say 15 Ft, as you say it is on the
Flying Bridge, and that is say 15 Ft above Waterline. Now you
effectivly have the tuner in the middle of a diopole antenna and trying
to reconcile impedances on both antenna and ground at the same time.
BAD IDEA. The firmware in the tuner only looks at the antenna
impedance, with refernce to the Ground lug on the tuner. If the ground
lug isn't at RF Ground, then the tuner firmware gets REALLY FUNNY DATA
from it's internal sensers and it doesn't deal with funny data well.
2. If the tuner is moved to a place, say 3 ft from the RF Ground, then
you must add wire to the antenna, and that wire becomes part of the
antenna, and therefore gets tuned by the tuner. This is a GOOD THING,
if people, or Ground don't come to close to it while you are
transmitting. By adding wire (length) to the antenna you are effectivly
lowering the frequency that the tuner will tune. This again is a GOOD
THING, on a plastic or wood vessel.
3. As Larry and Jim have stated, check and BE SURE, that the radio is
in TUNER MODE, and not THRU MODE. If your in THRU MODE, the tuner

isn't
even going look at your antenna, let alone try and tune it.


More information!


Bruce in alaska
--
add a 2 before @