"Reg Edwards" wrote in message
...

"Frank's" wrote
W7EL tells us that EZNEC doesn't display the surface
wave which obviously contains power. Would that affect
the efficiency using the integration technique?
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The surface or ground wave is the most important fraction of total
radiated power. The correct radiation pattern of a vertical antenna
shows maximum radiation along the ground. Angle of maximum radiation =
0 degrees.

When deducing efficiency, to omit power radiated along the ground from
the hemispherical integration will result in serious error.

( Efficiency by NEC4 ) / ( Efficiency by formula ) = 0.38

I can imagine other losses in addition to loss in the radials but to
have the other losses several times greater is a bit much. Where are
these large losses? Are they in the soil surface - the only other
candidate?
----
Reg.

Correct Reg, I had thought the modified RP card
considered ground wave, but it does not. I am working
on a combined integration including the surface wave,
which should provide a more accurate indication of
the overall efficiency. I will also attempt the
analysis of various lengths of radial wires.

Frank