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Old October 1st 06, 09:25 PM posted to rec.radio.amateur.antenna
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Default Rhombics

On Sun, 1 Oct 2006 14:50:33 -0500, "Richard Fry"
wrote:

The purposes of my post were to state that (1) many NEC evaluations show a
combination of the radiation from the antenna PLUS the propagation effects
for the chosen earth parameters and antenna elevation, and (2) even when
such an approach shows zero field in the horizontal plane for a ground
mounted vertical monopole up to 5/8-wave high, that h-plane field in reality
is NOT zero _as it is radiated_ by the antenna.


This is simply an example of misusing a tool, not the evidence that it
lacks the capacity to show characteristics as they exist. Anyone can
conspire to fail.

In fact for distances just into the far-field region for the radiator
defined in (2) above (far field usually being defined as further than
2H^2/lambda from the antenna), h-plane relative field is virtually 100%,
regardless of ground conditions.


As I pointed out once before, NEC (EZNEC in particular) will exhibit
fields from any antenna that are consistent with Brown, Lewis, and
Epstein's field data to within 1dB. I would further note that their
data all exhibited values that lay below 100% (if by 100% that is
meant to be theoretical).

73's
Richard Clark, KB7QHC
 
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