Topband: NVIS Antenna

[John Kaufmann]

Inverted vee dipoles do produce some vertically polarized radiation off the
ends.  However, that vertical component has maximum gain at zenith, i.e.
straight overhead.  It does not contribute to any significant low-angle
radiation.  You can see this by doing an antenna model.

73, John W1FV

-----Original Message-----
From: Topband
[mailto:topband-bounces+john.kaufmann=verizon.net at contesting.com] On Behalf
Of Jim Brown
Sent: Sunday, March 15, 2020 2:36 PM
To: topband at contesting.com
Subject: Re: Topband: NVIS Antenna

Hi Ed,

I've studied this extensively for horizontally polarized antennas, but 
only for flat ones; I thin that inverted Vees have some vertical 
components.

For horizontally polarized antennas, maximum gain at high angles occurs 
at a mounting height of about 75 electrical degrees, and falls by only 
about 1 dB if raised to 120 electrical degrees. By "high," I'm talking 
70 degrees elevation.

Also, RX is different from TX, in that with RX we don't care about loss, 
only signal to noise. Ground loss is a contributor to those variations 
based on mounting height. N6RO, an old hand on topband with a great 
antenna farm, rearranges his M/6 station for topband contests to bring 
LOTS of his antennas to the station he uses single-op.

That study is here.  http://k9yc.com/AntennaPlanning.pdf

73, Jim K9YC