Ralph Mowery wrote:

"Bruno" wrote in message ...
Hi all,

I've had a planning application for a tower turned down which is a real
pain. My options are now very limited. I'm in a bungalow with a roof apex
height of 18 feet and I'm not allowed to put up anything much above this
roof line it transpires, so inverted vees that need to be mounted high up
at the feed point like G5RVs are not possible for me. My garden
boundaries limit the length of any wire antenna I might wish to put up to
about 120 feet overall. On the plus side, though, the QTH is several
hundred feet ASL close to the top of the hill and am not overshadowed by
any trees or buildings to speak of.
What's my best choice for an HF antenna under these circs? (I mostly do
CW on 20m & 40m, but would like a bit more band choice ideally if poss).
Many thanks.

You will not need a tower, just a pole to support a HEX Beam. It is
basically a 2 element beam and they seem to work very well at heigths of
around 20 feet. Most are from 20 meters up, so a wire dipole for 80 and 40
metes will probably be needed also. A trapped dipole will shorten it up
slightly .

20 feet is just a bit less than a half wave at 20 M, so a HEX beam (or any
horizontal antenna) will work fairly well at that height. For the bands
above 20 M you are above a half wave length.

A dipole for 40 or 80 meters at 20 feet will radiate straight up, which
is OK if you are only interested in local communications. FYI miltary
NVIS communications useually takes place on 2-4 MHz at night and 5-7
MHz during the day.

--
Jim Pennino