Topband: antennas close to ground

[Carl Luetzelschwab]

Mike W0BTU commented:

"But I thought that it was a well-established fact that NO antenna modeling
software does well with antennas close to the ground".

Yes, I believe that's true with the NEC-2 computational engine. The NEC-2
engine is readily available to the public.

The NEC-4 computational engine addresses antennas very close to ground,
buried antennas and antennas connected to non-perfect ground. The NEC-4
engine requires a license from Lawrence Livermore National Labs - it is
$300 for US Non-commercial entities. This does *not* include the antenna
analysis software.

N6LF used NEC-4.2 (with EZNEC Pro4 v6) in his article that I recently
cited, and his results were very good for what he simulated and measured
(one buried antenna, one antenna very close to ground and a vertical wire
with a ground rod).

Of course just having the NEC-4 engine doesn't guarantee success, as N6LF
pointed out. You must have an accurate model of your ground conditions, you
must obey the wire rules, you must have accurate dimensions for the
antenna, and if it's wire you should include the insulation, too.

That's my two cents worth.

Carl K9LA