"Roy Lewallen" wrote in message
...
This can easily be done with the free EZNEC demo program available from
http://eznec.com. Here's a step-by-step for the demo or any other EZNEC v.
4.0 program:

1. Open example file Vert1.EZ. (Click the Open button, enter Vert1, then
.........

.........Objects, then check the 2D Pattern box. This will superimpose a
correctly oriented 2D pattern on the drawing of the antenna.

I did the experiment using a 30 degree tilt, and found a difference of
1.31 dB at an indicated elevation angle of 30 degrees. That would be at
the horizon, taking into account the ground tilt. At an indicated
elevation angle of 40 degrees (10 degrees above the horizon when ground
tilt is considered), the difference is 1.77 dB. You can modify the ground
conductivity and permittivity and repeat the experiment to see how this
changes with different ground types.

Roy Lewallen, W7EL

Frank wrote:

Since NEC cannot model a sloping ground, just try modeling a leaning
vertical, and see how it effects the pattern. I seriously doubt there
would be much difference. Certainly nothing you would notice.

Frank

Thanks for the info, but I already have the EZNEC demo. It does seem to be
an excellent program, providing a low cost antenna modeling tool. I have
been using another version of NEC for quite a few years and, to be honest, I
prefer to work directly with the NEC cards. I feel lost if I cannot get in
and edit the lines of code. I must admit I often use some of the
additional program features to check if I have the correct card sequence,
and also for tag rotation. I can also use any card listed in the NEC User's
Guide.

Fact is I was not that interested in actually modeling a leaning vertical,
although the problem is trivial. Now that you have done it, I may give it a
try to see if I get the same results. Assume you used a slightly elevated
radial ground plane with the S/N ground model applied.

Regards,

Frank