"Roy Lewallen" wrote:
EZNEC pro program types (EZNEC-M and EZNEC/4) allow direct inclusion of
the surface wave in the far field analysis, mostly for the use of AM
broadcast consultant customers. It provides tabular and graphical outputs
in the form of an azimuth plot at any desired horizontal distance from the
antenna and height above ground. Like NEC, the output is the total field,
or in other words the sum of surface and sky wave, and the results should
be virtually identical to those from NEC.
______________

This is as may be, and can be useful when properly understood and applied.

But is it not true that for the ground-mounted monopoles defined in my
previous posts, no form of NEC and its Windows shells will show in a
_single_ evaluation whether in tabular or graphical form, the net values of
the surfacewave+spacewave elevation pattern at a user-specified distance
over real earth, for all elevation angles in a given azimuth slice?

RF

Richard Fry wrote:
______________

This is as may be, and can be useful when properly understood and applied.

But is it not true that for the ground-mounted monopoles defined in my
previous posts, no form of NEC and its Windows shells will show in a
_single_ evaluation whether in tabular or graphical form, the net values
of the surfacewave+spacewave elevation pattern at a user-specified
distance over real earth, for all elevation angles in a given azimuth
slice?

NEC can do that in a single run. You'll need an RP "card" for each point
on the curve, each specifying the horizontal distance and zenith angle
of the observation point. The reason that so many "cards" are necessary
is that to maintain a fixed distance from the antenna, the horizontal
distance must decrease as the elevation angle increases. And
specification of distance in NEC (and EZNEC pro) is done as horizontal
distance, not radial distance. See the NEC-2 manual for detailed
information.

In the more than ten years EZNEC pro has had ground wave analysis, I
believe your recent request is the only one I've ever gotten for such a
display. Apparently EZNEC pro users, like me, don't see any practical
use for one.

Roy Lewallen, W7EL

On Sun, 1 Oct 2006 17:50:47 -0500, "Richard Fry"
wrote:

no form of NEC and its Windows shells will show in a
_single_ evaluation whether in tabular or graphical form, the net values of
the surfacewave+spacewave elevation pattern at a user-specified distance
over real earth, for all elevation angles in a given azimuth slice?

I'm surprised that Roy didn't take credit for this where credit is
due.

The near-field table (which complete conforms to your constraints) can
be expressed in a spherical coordinate system. I've used this feature
often.

73's
Richard Clark, KB7QHC