sctvguy1 wrote:
I have an old boatanchor, a Lafayette HE-10, that takes a single wire
antenna and a ground. I would like to make a simple trimmer to optimize
the 75 feet of random coated wire. The wire is copper, Radio Shack.
Thank you,
Bob Grimes

If you mean a simple means of shortening the wire to a resonant
length, simply roll the end of the wire into a ball, no special
winding or anything, just like a ball of twine. This method is
often used as a counterpoise on some of the multiband whips
where a ground is not handy. B&W make one, and so does
MFJ. You can download their manuals and read what I have
just described. I have used a homebrew look-alike
to the B&W AP-10 which uses the same method for the counterpoise
and it worked well. And you don't have to cut the wire. As well,
you can roll or unroll the ball to adjust the length for different
frequencies. In an emergency you just take it off the ground
end and connect it to the antenna -- it works! Simplest and
cheapest antenna system you can imagine!

The ball of extra wire acts like a choke and has no real effect
on anything other than to effectively shorten the wire.

Hope this helps!

Irv VE6BP