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#11
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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 @ |
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Icom 802 troubleshooting
SGC has always maintained that the coupler/tuner should be mounted as
close to the base of the antenna as possible. Links: http://www.sgcworld.com/support/golden_rules.htm http://www.sgcworld.com/ftp/Books/SG230Man.pdf (pages 10, 41) You are right in that the antenna starts at the tuner. With the all RF generated every time you key the mic, that is precisely WHY you want the lead from the tuner to the antenna as short as possible. The idea is to have as little of the antenna radiating inside the boat as possible. Gary Schafer wrote in message . .. Why do you say that? The lead that goes from the antenna tuner to the antenna becomes just as much a part of the antenna as the rest of the antenna wire. It is much more important to have a low inductance (short) ground lead. Regards Gary On 15 Nov 2003 12:10:55 -0800, (Mark Reichow) wrote: Leave the tuner as close to the antenna as practical. That's much more important than the distance to the ground plate. |
#13
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Icom 802 troubleshooting
Also read Gordon West's excellent primer on radio gound planes for
boats. It comes packed with the West Marine 2" copper foil gound kit, which by the way comes in 25' AND 50' lengths. (That may say something about the length of gound leads right there.) He points out that the tuner is mounted next to the antenna on the flybridge of power boats, and at the base of the antenna (backstay) of sailboats. |
#14
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Icom 802 troubleshooting
You don't suppose they are trying to sell ground foil do you? :)
Ask Bruce about ground planes on fly bridges. :) Regards Gary On 22 Nov 2003 04:18:15 -0800, (Mark Reichow) wrote: Also read Gordon West's excellent primer on radio gound planes for boats. It comes packed with the West Marine 2" copper foil gound kit, which by the way comes in 25' AND 50' lengths. (That may say something about the length of gound leads right there.) He points out that the tuner is mounted next to the antenna on the flybridge of power boats, and at the base of the antenna (backstay) of sailboats. |
#16
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Icom 802 troubleshooting
A valid point but Gordon West also states that with the modern
couplers/tuners, we no longer need to run huge amounts of ground foil and to link EVERY thru-hull to have a good ground plane. It used to be that a MINIMUM of 100 sq. ft. of counterpoise was recommended. He's a ham who writes books and magazine articles offering advice on the best way to install your HF radio system. I don't think he'd risk his rep telling you to install an inferior ground plane just to sell some foil. And I don't think SGC has a monetary interest in telling us to mount the coupler as close to the base of the antenna as practical. In any case, I've istalled my system and others this way, all with great success. Regards, Mark Gary Schafer wrote in message . .. You don't suppose they are trying to sell ground foil do you? :) Ask Bruce about ground planes on fly bridges. :) Regards Gary On 22 Nov 2003 04:18:15 -0800, (Mark Reichow) wrote: Also read Gordon West's excellent primer on radio gound planes for boats. It comes packed with the West Marine 2" copper foil gound kit, which by the way comes in 25' AND 50' lengths. (That may say something about the length of gound leads right there.) He points out that the tuner is mounted next to the antenna on the flybridge of power boats, and at the base of the antenna (backstay) of sailboats. |
#17
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Grounding for HF SSB, tiny surface area works OK?
Didn't Gordon West recently publish the results of an informal experiment where
his only ground was simply a short wire hung off the boat touching salt water, (not a long length dragged behind the boat)? As I recall, against all common wisdom, it worked great. The article called into question the need for big surface areas of grounding material if in salt water. It implied that simply grounding to a metallic through hull might do the job. I know we still have the issues of coupler and antenna location, feedline, etc. |
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Icom 802 troubleshooting
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#19
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Icom 802 troubleshooting
I haven't read everything that Gordon West has written. But some of
the stuff, especially the comparisons he makes between systems, leaves a little to be desired. If he says "we no longer need huge amounts of ground foil etc. because of modern tuners", what does that tell you? That is like saying "my radio puts out a good signal". Compared to what? Modern tuners don't help the ground situation one bit. They haven't changed the laws of physics. The only thing a modern tuner does is let you get away with a poor ground system easier than the old manual tuners. Much less work involved to get the radio to operate. Not that it operates any better though. Just look at the quality of some of the SGC radios. Is it any wonder their manuals are a little off. I have seen countless manufacturers with very poor antenna system installation advice. Some people have finally realized that a good connection to the sea water is an excellent ground. Gordon West Being among them. Now if only people would come to realize the importance of SHORT ground leads. Regards Gary On 22 Nov 2003 10:15:46 -0800, (Mark Reichow) wrote: A valid point but Gordon West also states that with the modern couplers/tuners, we no longer need to run huge amounts of ground foil and to link EVERY thru-hull to have a good ground plane. It used to be that a MINIMUM of 100 sq. ft. of counterpoise was recommended. He's a ham who writes books and magazine articles offering advice on the best way to install your HF radio system. I don't think he'd risk his rep telling you to install an inferior ground plane just to sell some foil. And I don't think SGC has a monetary interest in telling us to mount the coupler as close to the base of the antenna as practical. In any case, I've istalled my system and others this way, all with great success. Regards, Mark Gary Schafer wrote in message . .. You don't suppose they are trying to sell ground foil do you? :) Ask Bruce about ground planes on fly bridges. :) Regards Gary On 22 Nov 2003 04:18:15 -0800, (Mark Reichow) wrote: Also read Gordon West's excellent primer on radio gound planes for boats. It comes packed with the West Marine 2" copper foil gound kit, which by the way comes in 25' AND 50' lengths. (That may say something about the length of gound leads right there.) He points out that the tuner is mounted next to the antenna on the flybridge of power boats, and at the base of the antenna (backstay) of sailboats. |
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Icom 802 troubleshooting
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