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Re: [TenTec] Rhombics

To: Rick - NJ0IP / DJ0IP <Rick@DJ0IP.de>
Subject: Re: [TenTec] Rhombics
From: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Reply-to: geraldj@weather.net, Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Sun, 05 Dec 2010 19:58:54 -0600
List-post: <tentec@contesting.com">mailto:tentec@contesting.com>
Its a receiving antenna. According to its paragraphs in the "Antenna 
Engineering Handbook" by Johnson and Jasik (not me), page 11-17, 
"Reception depends on the tilt of the arriving vertically polarized 
wavefront caused by local ground losses. The electric vector of the 
equiphase front, tilted forward, produces a component of electric force 
parallel to the wire, inducing a current in the wire This flows toward 
the receiver and is reinforced throughout the length of the antenna." It 
goes on to say, "Wave tilt increases with frequency and with ground 
resistivity. The length of antenna depends on the available land, up to 
the limit at which induced currents tend to be out of phase with the 
advancing wavefront. Directivity increases with length up to the above 

The Beverage receives in the direction of the wire. A long wire 
transmitting antenna has a null in the direction of the wire whether 
that wire has a traveling wave or a standing wave and the longer that 
transmitting wire, the more the lobes and the closer the strongest lobes 
approach the direction of the wire, but there's always that null. The 
truth is that the lobes seen in azimuth and elevation around a long wire 
are really cones with varying polarization but cones at that angle to 
the wire. When the wire is close to the ground much energy gets coupled 
to the lossy earth. But the Beverage only works when low to the ground 
for receiving.

Since the Beverage depends on a tilt of the advancing wavefront, that's 
something the wire can't create as a transmitting wire.

73, Jerry, K0CQ

On 12/5/2010 6:46 PM, Rick - NJ0IP / DJ0IP wrote:
> Jerry, can it be that there are too much ground losses due to its close
> proximity to ground?
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