"Richard Heindel" wrote in message
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A 1/2 wave will "get out" better than a 1/4 wave.

Except, of course, for the little detail that Adrian alludes to. Assuming
your dipole is 19" on each side, then doubling it to 38" on each side will
cause a problem -- the feed point impedance will be wrong. You will need to
do some impedance matching in order to get your RF into the antenna in the
first place. It's fairly tricky to do that without incurring noticeable
loss, but once the RF gets into the antenna, it will work better.

HOWEVER, if you have a dipole whose total length is 19", then doubling it so
it is 19" on either side will make it a whale of a lot better. A doublet
only 19" long in total is not only too short to resonate, but the feedpoint
impedance will prevent most of your RF from ever getting into the antenna in
the first place, so the performance of the system will be dismal.

A half-wave dipole, on 2 meters, one 19" on each leg, is a very good
antenna, providing you can take the feedline away at approximately right
angles to the antenna. Most of the other designs for 2 meters (short of
multi-element designs) are actually a little poorer than a dipole except
they solve that problem of the feedline coming off at an inconvenient place.
Since on FM you want a vertical antenna, a dipole is messy because you
usually want the antenna up high so you want the feedline to come up from
the bottom. In your case, where you can't get very much height, it may not
be much of a problem to bring the feedline out horizontally for a ways.

Now on 2 meters, height is everything. The J-pole Adrian mentions might
give you the opportunity to get a little more height, which will make it
work a lot better. The J-pole has the feedline coming in at the bottom,
just what you want. Although it is mechanically relatively simple to build,
some people report that it is very tricky to build right. Others seems to
make almost any approximation work well. If you can gain a little more
height by building a J-pole, then I would suggest you go ahead and try it.
There are all sorts of designs out there, and they are pretty inexpensive to
build. But if you are stuck with something close to your window, then then
dipole maybe a better deal.

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