[TenTec] Ashing for advise please!

[Joel R. Hallas]

Tony et al,

Unfortunately that "advice" mixes the two vertical antenna ground issues.
They say a vertical must operate against ground, which is patently untrue. A
vertical dipole, for example needs no connection to ground to operate very
efficiently, nor do properly designed electrical half wave vertical
antennas.

A quarter wave monopole, on the other hand does need a good ground to
efficiently accept energy. A single pole in the earth at its base is a very
poor ground connection and, while it will have a nice wideband SWR curve,
much if the power from the coax will heat the ground. A quarter wave
monopole with a few elevated resonant ungrounded radials will work very well
BTW. 

The other ground effect is the ground reflection. This can be considered, to
a first order, as if it were an optical problem. The Bencher site talks
about the radials as being "the mirror," but for any reasonable length
radials the reflection from the radial ground is only at high angles - where
the antenna doesn't radiate anyway. The low angle reflection occurs at a
large distance from the antenna, the lower the angle the further away. (BTW,
Tony and I were involved together on a USAF HF program almost 40 years ago
that had a large vertical array and our taxpayer $ paid for a ground screen
in front of it that was hundreds of feet long). This explains why verticals
work great next to the ocean if communicating seaward.

Best not to mix the two completely independent ground effects -- and I would
be very suspicious of either the motives or the expertise or both, of anyone
who does!

End of soapbox! 

Regards, Joel
Joel R. Hallas, W1ZR

-----Original Message-----
From: tentec-bounces at contesting.com [mailto:tentec-bounces at contesting.com]
On Behalf Of Tony Berg
Sent: Tuesday, September 23, 2008 11:32 AM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] Ashing for advise please!

Paul,

I suggest that you click on and read "Choosing a Vertical" in the
"Advice" box on the web page at www.bencher.com/ham/ .

73, Tony  W1OT
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