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Re: Topband: Best Height Above Ground for a Beverage RX Antenna

To: "Peter Koehler" <KJ7WY@arrl.net>, <Topband@contesting.com>
Subject: Re: Topband: Best Height Above Ground for a Beverage RX Antenna
From: "Tom Rauch" <w8ji@contesting.com>
Reply-to: Tom Rauch <w8ji@contesting.com>
Date: Thu, 11 Jan 2007 17:59:08 -0500
List-post: <mailto:topband@contesting.com>
> New to beverage antennas, I've been reading your posts 
> with interest. It
> seems all agree that lower is better. My problem is that I 
> have to have
> a 10-12 ft high beverage (people and Elk). I was wondering 
> if anyone has
> tried to put a grounded wire 2-3 ft below their entire 
> beverage. As Milt
> did over his arroyo runs. Would this change the apparent 
> height above
> ground?

Pete,

A conductor below an antenna will always oppose the 
radiation (and reception) of a wire above it. It does not 
really establish "height" in a Beverage, because a single 
wire or a few wires would be tightly coupled to earth and 
very lossy. A Beverage depends on high earth losses to work, 
and it depends on a reasonably wide lossy area to establish 
effective height and performance. It just isn't what is 
immediately under the wire, but what is also off to the 
sides a good distance.

That's actually what started this whole thread. The Beverage 
Handbook incorrectly suggests installing a "return wire" 
below a Beverage. That clearly is a terrible idea. If the 
wire worked with low loss and really "returned signals" from 
the far end (which is also a false concept) the wire would 
cancel all Beverage-mode reception.

The only reason it doesn't stop the antenna from working is 
because a wire closer to earth has significantly more loss 
than the wire placed higher. We all know (or should know) a 
Beverage stops working over very good ground, so why would 
someone go out of their way to make the ground below the 
antenna move in that direction?

Unfortunately when something bad makes it into print it just 
never dies.

73 Tom 


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