On Sun, 3 Oct 2010 18:40:58 -0700 (PDT), Professor
wrote:

Is a Screw Driver antenna nothing more than an antenna tuner you mount
to a vehicle with a piece of wire attached to it?

Sort of.

After you accept that as the objective the clean up involves:
Physical details ... rugged beyond belief, small enough to be
acceptable... maintainable...weatherproof... under daily hurricane
conditions... affordable materials

install issues... different vehicles require a lot of flexibility in
mounting.

I have a project underway where I expect to have a Homebrew T-Match
tuner at the base of a vertical antenna at my QTH. I plan to drive
the mechanics with three $10 electric screwdrivers. Locating the
tuner at the antenna will allow the feed line to operate at a low SWR
which will keep feed line losses to a minimum and rf out of the shack.
Since the contraption will be in the garden shed most of the difficult
aspects of a vehicle mounted screwdriver antenna will be out flanked.

If you sit down and plan it through I expect you will conclude that
the only reasons that you might have to homebrew a vehicle mounted
Home brew Screwdriver antenna is that you have excess time and
materials or you think you can improve on the commercial offerings.

Sometimes my only real motivation is that I have to homebrew an item
before I can fully appreciate the commercial offerings!

BTW, an SGC-237 tuner and a 28 foot whip will tune all of the HF ham
bands automatically and fast! That set up will cost a lot more than a
commercial screwdriver but you can consider that as an ideal
arrangement and compromise your way back from there.

Good Luck,

John Ferrell W8CCW