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Old 26-03-2011, 20:14   #1
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SSB antenna for Catamaran

We are just about to set off on a cruise, and I just realized that my rope antenna is broken. So I need a new antenna in a hurry -- but it still needs to be good .

I was thinking of running about 55 ft of regular marine 12guage insulated tinned copper wire (not naked wire) up in place of the core in some line.

Would this work well? I'm looking for something that would work well.

Any particular length from tuner to end of antenna? Any wire better than others?

I can actually feed the bottom end of the line through a deck gland that is amid ships on the port side and connect it directly to the tuner right below the gland. And thereby skip a 'feed line'.

I know there is a lot of info on the site, and I have read through most of it, and it seems like this would work. But I'm hoping one of the guys with lots of knowledge, could opine on whether this is just a make shift solution or whether this could be a good permanent solution.

Some more info on my setup: I just installed my M710 and AT130 tuner in my port hull. the tuner is about two feet below the deck, and about 5 feet above the ground plate. RF Ground iss connected with solid copper strap, and my ground plate is set off from the hull about half and inch below the hull.

I have no backstay as this is a cat. And the swept back shrouds do not have insulators, and my mast is carbon, so i didn't really want to mess with that.

Any thoughts would be appreciated!!

Thanks,
Arthur
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Old 27-03-2011, 05:12   #2
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Re: SSB antenna for Catamaran

Seal the end of the 12-gauge wire so that no moisture can get in; connect the other end to the tuner and hoist it up or tie-wrap it to a line or put it inside a single-braid line etc.

The alternative is a fiberglass whip antenna on the stern. I have both and both work equally well. ( we have no backstays either).

ciao!
Nick.
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Old 27-03-2011, 05:49   #3
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Re: SSB antenna for Catamaran

If you want a really robust seagoing "alternate backstay" antenna, use insulated s/s lifeline. Mine has lasted over 20 years, and I've installed a bunch of them on client's boats.

Here's one way to attach the GTO-15 feedline to the alternate backstay antenna: DSC_0343ps

One good solution on a cat, also, is to insulate one of the shrouds at the top only, and feed it from belowdecks at the chainplate. This works very well IF you have only one shroud on a chainplate...unfortunately, many cats use the same chainplate for multiple shrouds.

Plain old copper wire won't last very long in a real seagoing environment.

Bill
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Old 27-03-2011, 07:33   #4
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Re: SSB antenna for Catamaran

Thanks for the input guys.
Insulating the shroud won't work the way the rig is set up.
And as to the whip, I had a whip, but I found my rope antenna (the one that broke) worked much better than the whip. That may be because of length, or because the whip had to be at a fairly significant angle off the stern (It couldn't be straight up and down due to the boom.

Bill, is your concern about the insulated copper wire just about durability? If we set durability aside for the moment, will it transmit and receive well?

Anyone have thoughts on length?

unless I hear other suggestions I think I'll try sealing up the top end of the copper wire.
The bottom end will be below decks.
I'm hoping a rope sheath will take the hoisting load, and that the wire will just float in middle as the core (like the rope antenna). and I can always carry a spool or two of copper wire.

thanks again,
arthur
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Old 27-03-2011, 07:47   #5
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Re: SSB antenna for Catamaran

Quote:
Originally Posted by hoaga View Post
....

Bill, is your concern about the insulated copper wire just about durability? If we set durability aside for the moment, will it transmit and receive well?

Anyone have thoughts on length?...
arthur
Yes. Durability. Any copper wire will work well, until it corrodes/breaks.

A length of about 40' will work well.

Bill
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Old 27-03-2011, 08:46   #6
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Re: SSB antenna for Catamaran

I have the same system as you and a similar installation but I have the Gam antenna system. Pricey but works great and very easy to install. Bosuns chair and zip ties!
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Old 27-03-2011, 15:52   #7
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Re: SSB antenna for Catamaran

Quote:
Originally Posted by hoaga View Post
That may be because of length, or because the whip had to be at a fairly significant angle off the stern (It couldn't be straight up and down due to the boom.

Bill, is your concern about the insulated copper wire just about durability? If we set durability aside for the moment, will it transmit and receive well?

Anyone have thoughts on length?
Yes, the fiberglass whip must be vertical.

I'm sure it won't last as long as steel wire as used for lifelines but my 10-gauge black tinned wire is more than 5 years old now and still doing good... and it isn't inside anything, I just raise it with a halyard.

40' - 55' is what I see used by most. Don't forget that any wire/cable connecting a stay or something to the tuner is also part of the antenna and thus the total length.

ciao!
Nick.
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Old 27-03-2011, 19:03   #8
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Re: SSB antenna for Catamaran

Thanks again everyone.
I think I'll try the copper wire I have as a short term solution.
And when I get a chance I'll try the coated stainless lifeline solution Bill suggested.

Thanks again,
Arthur
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Old 27-03-2011, 20:20   #9
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Re: SSB antenna for Catamaran

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Originally Posted by Loco Gato View Post
I have the same system as you and a similar installation but I have the Gam antenna system. Pricey but works great and very easy to install. Bosuns chair and zip ties!
I second this solution... Works well.. and quick install...
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