Why does "the tuner need to be as close to the antenna as possible"?
The antenna lead is always part of the antenna. If the tuner is far
away from the ground the ground is part of the antenna which is
unwanted.

It doesn't matter how long the lead from the tuner to the antenna is
but it does matter how long the ground lead is.

By the way, most AM broadcast stations use 120 radials not 36. And
they are DIRECTLY under the antenna tuner! Very short ground lead.
Hint, Hint.

Trailing a 120 foot wire behind the boat is like soldering a 120 foot
long piece of wire to a sheet of copper a mile or so square, to try
and make a lower resistance connection to the copper.

A small plate a few inches into the sea water will provide as low an
impedance as you are going to get. Sea water is a much better
conductor providing a much lower inductance than a long piece of wire
ever will.

The important thing is to have the lead between your water connection
as short and as large as possible to keep its inductance down.

Regards
Gary



On Sat, 15 Nov 2003 14:29:18 GMT, (Larry W4CSC) wrote:

DO NOT MOVE THE TUNER away from the antenna! I don't know where he
got this nonsense, but the tuner needs to be as close to the antenna
as possible. The more ground connections to the ground terminal on
the tuner, the better. Broadcast AM stations with similar antennas
use 36 ground radials laid out around 360 degrees, 1/4 wavelength
long, to get a great ground. On a boat, of course, this isn't
possible. What IS possible and works really great is to use a
trailing ground radial, about 100' long is great. Use insulated wire
sealed at the trailing end to keep the seawater out and as big a guage
as you can. I'm using 120' of #12 bright orange wire with a little
plastic cup on the end as a sort of sea anchor to pull on it as the
boat moves through the water. That holds it out flat very nicely.
The effect is you have created a huge L antenna with the vertical your
insulated backstay (or whip or whatever) and the horizontal part
trailing 120' out behind the boat, with the tuner at the feedpoint.
My ham radio signal reports increase nearly 10 dB with the trailing
ground deployed. Of course, don't forget to reel it in before you
back down or drag it over those obstructions. It works great, also,
at anchor. Ground the tuner to your anchor chain rode with a jumper
cable. The trailing wire will wrap up the anchor in the tide. At the
dock, if you like to play as I do, simply drop a ground wire over the
side and let it lay on the bottom with a sinker to hold it.
Otherwise, Lionheart's tuner is hooked to the engine block below it
with a piece of painted copper flashing from the hardware store.



Larry W4CSC

"Very funny, Scotty! Now, BEAM ME MY CLOTHES! KIRK OUT!"