On Sat, 11 Jun 2005 06:39:12 GMT, William Taylor
wrote:

http://www.hamuniverse.com/supernvis.html

The claim is that a dipole 7 feet off the ground has
a 10db gain over a G5RV at 50 feet.

Is that possible, or hype?


I'll take a stab at it. First of all, its objective is to create
nulls at low-take-off angles so shortwave broadcast stations will not
have so much noise. The antenna is a 300 ohm folded dipole that is
fed with 50 ohms but then the antenna has a reflector on the ground.
It is effectively a 2-element yagi pointed strait up (give or take a
few degrees at the user's choosing.)

I don't think a two element beam has a 10 db gain, but I don't know
the gain of a G5RV on the same frequency. Presumably, the signal
strength of local signals will improve and DX or broadcast stations
will drop.

This is known as a Near Vertical Incidence (I forget the 's') antenna.
Great for operating local districts on 160-30 meters. If the dipole
is raised high enough, it will be just a dipole, but then it will be
mis-matched to the feedline and have considerable loss.

This is my theory, correct me if I am wrong

--
73 for now
Buck
N4PGW