I have tried entering the model shown in EZNEC 4

The "View" of the antenna looks fine but when I try to run the
simulation it reports that it cannot because the gain is negative.

I then changed from azimuth to elevation simulation but this time it
reported the maxim 500 segments were exceeded.

I then reduce the segments slightly but now the program reports Runtime
error M6201: Math Sqrt Domain error.

ie. Cannot get the model to work using EZNEC. I'll see if it will run in
MNANA.

Richard Clark wrote:
On Mon, 10 Oct 2005 16:05:16 GMT, "Frank"
wrote:


My model is only valid providing the coax has no current on the exterior of
the shield. All I did was extend one leg of the dipole by the length
specified, but not actually connected to it; with a 1.2" gap. As per the
following sketch.

----------o---------- ----------
dipole extension

Do you think it makes sense? It is the only way I could think of modeling
it with NEC.


Hi Frank,

No. The extension lies in the null of the dipole. As such, it would
be no mystery that it has so little influence.

To model it correctly requires some form of cage or skirt of wires as
Wes has provided in this thread.

73's
Richard Clark, KB7QHC