The message m
from Ray Anderson contains these words:

Thomas wrote:


What about free versions of the NEC code?

I am interested in modeling a helically wound antenna and so need a lot
of segments.

Thanks.

Thomas

For free packages, I find the 4nec2 program amongst the most powerful
and easy to use. You can download it from the NEC Archives at
http://www.qsl.net/wb6tpu/swindex.html

It has most, if not all, of the features of many of the commercial
packages plus a few that they don't have. I believe the NEC2 engine
underlying the gui is set up to handle up to 11,000 segments.


-Ray WB6TPU

Can confirm all that Ray says. 4nec2 is an outstanding program that is
constantly having new features added. The 3-D viewer is spectacular and
generates 21 shades of colour denoting gain in dBi superimposed over
antenna structure. Rotates in 3 dimentions.

Has Optimizer for SWR, Gain, F/B, F/R, input resistance and input reactance.

You can specify insulated wire. Arie supplies 25 different coatings.

Has standard .nec input and output file format so unlimited amount of
antenna designs can be studied. Entry level commercial programs have each
their own unique file format so tying you into their system.

Has Geometry Builder so if you wish you can graphically input your new
antenna.

And as Ray said 11,000 segments and patches.

Much, much more.

Download 4nec2X and you will get the realtime 3D viewer.

Arie is to be congratulated on making his program freely available.

Deryck G0KOR