On Wed, 7 Apr 2010 13:51:18 -0700 (PDT), Bil
wrote:

I am starting to think of replacing the standing rigging of my cutter-
rigger monohull. The current rigging includes an insulated length of
the backstay (insulators top and bottom) which I use as the antenna of
my SSB transceiver (an ICOM M710 RT with an ICOM ATU).

A dock idler reckons that I could get a superior antenna by only using
a single insulator on the backstay - just the bottom insulator. That
would mean that the upper portion of the backstay, the mast, the
shrouds, and the forestays would all be parts of the antenna.

That dock idler reckons the ATU would tune the whole rig. And that
more metal in the antenna is effectively better.

Is this madness? Heresy? Or makes sense?

Cheers

Bil


Probably Larry will respond in detail but in the interim:

If you want to use the entire rig as an insulated antenna then all
points need to be insulated - forestay, shrouds, masts, etc. So you
will need a bunch of insulators. If the masts are keel steeped then
that has to be attended to. "Thinking out the box" seems to be all the
style but sometimes the "old fellas" were right.

Now having said that, there a type of antennas in which one end is
grounded and the antenna is shunt fed part way up one leg. I believe
that many AM stations use this type antenna. So it is possible, and I
have seen at least one boat who did it this way, by connecting the rig
normally and adding a shunt connector to either a back stay or one of
the shrouds. The bloke that used this system was, I believe a US Navy
radio type in a pervious life, and said it worked great albeit a bit
frequency sensitive.

So the bloke on the dock wasn't totally wrong, but neither was he
totally right :-)
Cheers,

Bruce
(bruceinbangkokatgmaildotcom)