Thanks for reading this. I've just been through a very confusing antenna
trial, and I'd really appreciate some info from hams who know more about
them then I.

My brother, W3TDH, called me up yesterday and asked me to help test some
80 and 40 meter antennas that his club is preparing for field day. He
told me that the club is going to serve their target coverage area by
using two dipoles, spaced 1/2 wave apart and fed in phase, so as to
maximize NVIS (Near-Vertical Incidence Skywave)radiation.

I'm not arguing with the design: antennas spaced 1/2 wave apart and fed
in phase always have maximum radiation at right angles to a line
bisecting both antennas. Ergo, two dipoles, horizontally mounted, etc.,
will indeed produce their maximum radiation straight up and down.

My question is: why would that be the best design? I thought that NVIS
radiation was a byproduct of having a radiator less than 1/2 wave above
the ground, and that it wasn't to be sought after, but rather avoided.
Leaving aside the losses due to 1/2 the power pointing straight down,
why would an antenna on 80 or 40 meters be most effective by radiating
almost straight up? Wouldn't the coverage be improved by phasing the
antennas so as to maximize radiation toward the horizon?

73,

W1AC

--
Bill Horne, W1AC

(Remove QRM from my address for direct replies.)