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Re: [TenTec] New and Improved Terminology (NVIS origins)

To: tentec@contesting.com
Subject: Re: [TenTec] New and Improved Terminology (NVIS origins)
From: Stuart Rohre <rohre@arlut.utexas.edu>
Reply-to: Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Thu, 06 Jan 2011 15:53:14 -0600
List-post: <tentec@contesting.com">mailto:tentec@contesting.com>
Severns, Cebik, and others have shown that even with elevated radials, 
it is hard to get equal currents in each radial, due to interaction with 
the type of ground below the radial.  While the elevated radial vertical 
quarter wave might approach the greater than 90 per cent efficiency of a 
dipole, a vertical dipole elevated enough to not detune the lower 
element should look more and more like an ideal dipole the higher you 
place it above effective RF ground.

For some locations, it might be splitting dB's to say which gives the 
greater signal.  And you must consider what is in the near field of each 
as well as the far field behond 2 to 5 wavelengths.  (Is there a ridge 
or hill out there, that blocks a certain direction?)

-Stuart Rohre

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