Mounting ICOM SSB Antenna Tuner?

[PorFin]

Howdy folks,

I'm finally getting around to recommissioning our SSB, part of which is relocating/mounting the AT-120 auto antenna tuner.

The user's guide says to mount it "vertically or horizontally"... How literally do I need to take this? In other words, can I mount it on the inside of the hull on a ~20 deg angle off vertical?

My first thought was that electrons really don't care about gravity, so this shouldn't be a problem. However, I'd hate to go the all the effort to glass in a mounting surface only to find out that I've made a poor assumption.

Thanks in advance,
Por Fin

[btrayfors]

That will be fine. You can even mount it upside down, like my SG-230 which has been underdeck for over 20 years :-)

Bill
WA6CCA

[PorFin]

Thanks Bill!

I'll proceed as planned.

The next step will be connecting the tuner to the backstay. The previous installation used RG-8X (outer layer, not the core), but I've read that primary wire is better. Your thoughts?

[btrayfors]

Use GTO-15 wire. It's highly insulated (to 15,000 volts), and is the wire normally used. You can find it at West Marine, and elsewhere. Not expensive.

There are several methods to attach directly to the backstay. I tend to favor the use of stainless steel wire clamps, the kind which are shaped like a U, with a bar and two nuts. Put a ring terminal on the end of the GTO-15 and connect it to one of the bolts. Use adhesive heat shrink tubing over the ring terminal to add strength and to prevent water intrusion. This method is easy, and it allows you to remove the terminal periodically to inspect it, clean it, replace it, etc.

Bill

[PorFin]

Thanks again, Bill!

[sailingdog]

PorFin—

You might want to consider installing the tuner with spacers between it and the hull. This will allow better air flow for cooling purposes and also give water that does get on the hull's surface a chance to pass between the tuner and the hull, rather than pooling on and entering the tuner box. Also, make sure you've got good drip loops on the wires.

[SVAuspicious]

Originally Posted by btrayfors

Use GTO-15 wire. It's highly insulated (to 15,000 volts), and is the wire normally used. You can find it at West Marine, and elsewhere. Not expensive.

GTO-15 is definitely the way to go. You may want to use Google to find a local neon sign shop; many will be happy to sell you the little bit you'll need for the run from the tuner to your antenna. If you don't have anywhere local order from RF Connection ( therfc.com ); Joel doesn't list GTO-15 in his catalog but he does carry it.

[btrayfors]

Dog...

Good suggestions, but the AT-120...and all other marine tuners I'm familiar with...come with a mounting bracket which maintains a good separation between the body of the tuner and whatever it's bolted to....automatically.

Mounting to a hull can be difficult, though. We often use special mounting studs which use an epoxy to bond to the hull, and include 1/4" studs for mounting. Depending on location, it's sometimes a good idea to bolt the tuner to, e.g., a piece of starboard and, in turn, bolt the starboard to the hull or bulkhead or wherever.

Drip loops on the wires are always a good idea, despite the fact that wire entries to the tuners are waterproof if properly fitted. It is a good idea as well to leave a "service loop", i.e., a short length of additional wire in case the ends need replacing/servicing.

Bill

[sailingdog]

The studs that you're describing are sold under the brand name WeldMount and use a two-part methacrylate adhesive that comes in a double-barreled syringe-type dispenser.

Originally Posted by btrayfors

Dog...

Good suggestions, but the AT-120...and all other marine tuners I'm familiar with...come with a mounting bracket which maintains a good separation between the body of the tuner and whatever it's bolted to....automatically.

Mounting to a hull can be difficult, though. We often use special mounting studs which use an epoxy to bond to the hull, and include 1/4" studs for mounting. Depending on location, it's sometimes a good idea to bolt the tuner to, e.g., a piece of starboard and, in turn, bolt the starboard to the hull or bulkhead or wherever.

Drip loops on the wires are always a good idea, despite the fact that wire entries to the tuners are waterproof if properly fitted. It is a good idea as well to leave a "service loop", i.e., a short length of additional wire in case the ends need replacing/servicing.

Bill

[btrayfors]

Dog,

Yeah, that's the stuff. Damned expensive, but it does the trick when there are no other good alternatives.

Thanks.

Bill