I'm planning on installint a 23' whip antenna on my boat with a
antenna tuner. I wondering what wire (size, type and grade) I should
use from the tuner to the antenna (not coax cable)?
#12-14 is fine, but the most important thing is it should be something
that won't corrode like stainless strap with holes drilled for the
tuner's output terminal. Copper is just eaten.....
The other most important thing lots of installations forget is this strap
is part of the ANTENNA and is NOT a transmission line. It should be as
short as possible and MUST NOT BE AGAINST OR NEAR ANYTHING CONDUCTIVE, or
it will make that object part of the antenna solution. I see this wire
neatly tywrapped to metal rigging to make it pretty all the time. Of
course, then the RF couples through the insulation on the wire and gets
sucked off into the rigging, or a metal box or some neat fitting they put
it through, sucking up the RF energy instead of radiating it. The
energy, unlike AC power, flows AROUND the conductor, not through it,
exactly. It radiates from it, as part of the antenna. So, if you get it
near any wiring, say some cables for other electronics because you're
trying to hide it from view, all those cables will be RF "hot", REALLY
hot at some frequencies where the impedance at the bottom of the whip is
quite high, and can destroy the equipment the cables are hooked to or at
least screw up their electronic operation.
One guy said every time he talked on HF/SSB, his radar reset and the
screen went crazy on his digital display. Further investigation found
the tuner hidden away under the flybridge console to keep it pretty with
the tuner to antenna link wire neatly tywrapped to a cable bundle going
that way. The whole cable bundle was RF "hot" when the transmitter was
on. On receive, of course, he heard every data bit that switched in the
cable...on his HF receiver.
Keep this wire far away from anything and screw the "pretty" if you want
to get a good signal on HF/SSB. The tuners are waterproof, mount it
right under the whip and feed the coax and control cables through the
bulkhead.
And NO TYWRAPPING TO THE HANDRAIL, EITHER!