I once built a open wire fed antenna to do just what
you propose.
It was 132ft flat top at 70ft. Hanging down from each
end was a 33ft piece of wire to form an inverted |_|
shape. 33ft out along the flat top on each side was
another 33ft piece of wire hanging down. So the
picture you draw is 132ft flat top fed in the middle
with 2 33 ft pieces of wire hanging down on each leg,
one at the end and one in the middle of each leg.
Imagine an inverted |_|__|_| fed at the center.
I made the open wire line out of parallel #12 magnet
wire, spaced 5" and it was fed to a custom made
transformer style tuner with custom wound plug in
coils for the tuner.
The antenna was a screamer. It was easy to match. It
was easy to build and still required only 2 supports.
Since you are in the planning stage, I would go with
the Johnson Matchbox KW style if you want to buy
something. Or build something. Bring in the feed
line, and don't use a balun setup. You will only have
to buy your Matchbox once, and it will not loose any
value. You will be able to get the majority of what
you have in it if not all or more when you decide to
sell it. It's like land, they ain't making anymore so
it holds its value. I have one now that I use to feed
a 138ft flat top. I have made a simple mod to the
matchbox to improve the range at the lower end, but it
does require adding a good quality switch. I figured
I'm going to die with mine so I really don't care
about the resale value. They go for about $300-$400.
If you don't run more than a few hundred watts, the
250W version of the Johnson matchbox is good for about
600-700W. They go for about $100
73 W9OY
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