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
K5KVH
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