Thread: Rhombics
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Old October 2nd 06, 12:02 AM posted to rec.radio.amateur.antenna
Roy Lewallen Roy Lewallen is offline
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First recorded activity by RadioBanter: Jun 2006
Posts: 1,374
Default Rhombics

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