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Discussion Starter · #1 ·
I am installing an Icom model 802 SSB and AT140 Tuner using a Kiss ground plane counterpoise . My installation directions say that the Tuner should be mounted as close as possible to the antennae (using an insulated back stay). My question is what would be the maximum distance I could mount the tuner apart from the anntenae and still achieve good results?
 

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Impossible to say. What are "good results"? The closer to the antenna, the better it will work. As it gets farther away, it gets progressively worse.

I would say mount it as close as you conveniently can, then try it out. If you don't like the results, find a way to mount it closer.

Good luck.
 

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Mermaid Hunter
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The antenna starts at the antenna stud on the tuner. The more of that you get high and more or less vertical the better.

Try to get it (the tuner) high and directly under the cable clam through the deck which should be as close to the bottom of the backstay as possible.

If you haven't put insulators in yet AND if you can reach the backstay chainplate AND you don't have a backstay adjuster you can run the GTO-15 feed from the tuner to the chainplate and install just one insulator a few feet down from the masthead. Be sure to lift any bonding wires from the chainplate.
 

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Discussion Starter · #4 ·
Oh I like that sugestion ! Unfortunately this boat already has insulators installed.:( But I now have a better underdstanding of how this connection needs to be made. There is a lazerette on the aft deck just infront of the backstay so i'll mount in there following your suggestions regarding orientation with the insulator up. There is a small "weep" hole on the opposite end where the connections emerge from the tuner so Obviously it is meant to be mounted vertically with the insulator up as you you pointed out . Thanks folks!
 

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Mermaid Hunter
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That sounds fine.

In the interests of best practice remember that hose clamps do NOT make good electrical connectors. Don't use a hose clamp to connect the GTO-15 to your backstay.

You'll want a bunch of self-amalgamating tape, a wire clamp, and a blue crimp ring terminal sized for the threads on the clamp. The U-bolt side of the clamp goes around the backstay just above the lower insulator. Run the GTO-15 between the legs of the U-bolt and capture it with the clamp. Put one nut on to keep it all together. Slip the ring terminal over the other side of the bolt and tighten everything up. Tape it. Pull the tape for inspection every year or so.
 

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Sailboat Reboot
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If you haven't put insulators in yet AND if you can reach the backstay chainplate AND you don't have a backstay adjuster you can run the GTO-15 feed from the tuner to the chainplate and install just one insulator a few feet down from the masthead. Be sure to lift any bonding wires from the chainplate.
I have great respect for Dave (Auspicious) and his knowledge. I agree you can forgo the bottom insulator on your backstay. What he knows (I am sure) but fails to mention is that by doing so the entire backstay becomes the antenna. When transmitting you are then putting out RF into the cockpit and hence the helmsman from a few feet away. This is not a particularly good idea.

With respect to "good results.' My installation (Kenwood TS-480HX and SEA tuner) is far from "ideal." My counterpoise connection is not a copper band but rather a hunk of wire. My feed to the backstay actually has a couple of loops in it so that I can disconnect the backstay without having to disconnect the antenna feed. Even so, using only 50 watts or less of power I routinely communicate 2,000 NM or more while at sea. I know I could potentially improve the situation by using "best practices" but doing so it well down my list off boat projects because at the moment my setup is "good enough."

Fair winds and following seas :)
 

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Mermaid Hunter
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I have great respect for Dave (Auspicious) and his knowledge. I agree you can forgo the bottom insulator on your backstay. What he knows (I am sure) but fails to mention is that by doing so the entire backstay becomes the antenna. When transmitting you are then putting out RF into the cockpit and hence the helmsman from a few feet away. This is not a particularly good idea.
Hi Roger!

You're going to make me blush.

It doesn't make any difference. Remember that the antenna starts at the tuner stud. GTO-15 is not shielded. It is only heavily insulated. It radiates just like the backstay. Same same.

The good news is that the currents are low (mostly) and the field strength is relatively low also.

Radar is a bigger issue because 1. the power levels are higher and 2. the radar wavelength is disturbingly close to the resonant frequency of your eye.

Upshot - you are correct to be concerned about radiation exposure. HF isn't a significant problem. Radar is.

I recall some concern about VHF exposure to law enforcement (lots of time on the radio - much more than we ever would even using only handhelds). Nothing was ever shown.

I think you should be more concerned about your cell phone than about HF radio.
 

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Sailboat Reboot
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Dave:

Thanks for the information. Question - is there any know impact from all of these sources on pacemakers? We old guys need to know! I never know what might be in my future!
 

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Mermaid Hunter
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Question - is there any know impact from all of these sources on pacemakers?
That's a great question. I don't have a good answer. I know microwave ovens are a risk. It seems unlikely that HF would be a problem. I know a guy that works in medical equipment. It's probably out of his own experience but I'm sure he knows someone that will know. I'll ask.
 

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the pointy end is the bow
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I read somewhere that if the auto tuner can be installed outside, that makes for a better installation, but then you're getting further away from the ground portion of the antenna. All this radio gobbledygook has me looking for a local HAM class so I'll be able to figure out exactly what I did wrong after I screw up my installation.
 

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Mermaid Hunter
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I read somewhere that if the auto tuner can be installed outside, that makes for a better installation, but then you're getting further away from the ground portion of the antenna. All this radio gobbledygook has me looking for a local HAM class so I'll be able to figure out exactly what I did wrong after I screw up my installation.
I'd be interested in the source for that. Icom AT-140 is okay outdoors but I don't think it would take kindly to green water.

Some of the Naval Academy YPs have the tuners on a rail but but they are easily 20 feet above the waterline and the YPs don't go offshore.
 

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the pointy end is the bow
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I'd be interested in the source for that. Icom AT-140 is okay outdoors but I don't think it would take kindly to green water.
If getting wet wasn't a factor, should the tuner be mounted outside close to the backstay? The advice I read said there was considerable loss in the short distance from the tuner inside while making its path outside the boat. I don't have the necessary education to judge that statement myself but if that was the case, I was considering constructing a weatherproof box on my RADAR mast which is very close to the backstay.
 

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Ray,

Don't bother (with the outside mounting box for the tuner). Just install it underdeck in a dry location as close to the bottom of the antenna as you can. No need to be paranoid about this.

Make all connections clean and tight, using the proper wire. Dave's suggestion re: attaching GTO-15 to the backstay is pretty close to the practice I've used on clients boats for years. Just a s/s wire clamp (U-bolt) of the right size for your backstay, and an extra nut to hold the ring terminal in place. Makes a good tight connection and one easy to inspect periodically.

Solid 5/8" nylon rod with a hole drilled in the middle makes good standoffs if you want them. I make them up in my shop, using wire ties to attach them to the backstay and the GTO-15.

Bill
WA6CCA
 

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Mermaid Hunter
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If getting wet wasn't a factor, should the tuner be mounted outside close to the backstay? The advice I read said there was considerable loss in the short distance from the tuner inside while making its path outside the boat.
Hi Ray,

The YPs I referred to have aluminum houses. Mounting the tuner on the rail at the base of the 23' fiberglass whip makes sense.

As I noted earlier the antenna starts at the antenna stud on the tuner. In the best of worlds you'll have the tuner above the waterline (so you aren't wasting energy radiating into the water) as close as possible to vertically below the external portion of the antenna.

There shouldn't be any practical loss per se from the GTO-15 inside a fiberglass boat above the waterline. Your radar has a fiberglass radome, right? The GTO-15 inside the boat has the hull as a fiberglass radome.

The lazerette location you described is just fine. No problem. If you have cowl vents into the lazerette or leaks you might want to bolt a rubber or vinyl sheet to protect the top of the tuner. Shouldn't be strictly necessary but extra credit for protecting the connection from corrosion.
 
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