On Wed, 26 Nov 2008 03:39:41 -0800 (PST), Richard Fry
wrote:

"Roy Lewallen" wrote
Of course the standard far field analysis doesn't accurately depict the
field close to the antenna -- it's a plot of the field at points very
distant from the antenna, as clearly explained in the manual. NEC allows
you to include the surface wave if you want, and it accurately shows the
total field including the surface wave at a distance of your choice.
_________

Not the versions of NEC used by most amateurs.

Those versions show zero or very low gain in/near the horizontal plane
for a
vertical monopole over real earth. This leads to the common (mis)
belief
that those are the gains of the radiation pattern _originally
generated_
by the monopole.

But that belief is untrue.

RF

Roy and others have answered this one in the past too. You employ the
near field table to observe the ground wave. It works approximately
well, even out to the edge of the implicit flat universe. If you
object to flat universes, you are no longer in the realm of ground
wave. If anything, modelers give MORE response in comparison to the
BL&T data.

73's
Richard Clark, KB7QHC