Re: NEC-LIST: NEC4WIN95 antenna simulation software - experience?

Ulf Lange wrote:
>
> Anyone that has tried/evaluated the new NEC4WIN95 antenna simulation
> software for Win95? It now comes with an optimizer (like K6STI's AO) and
> a demo is available at
>
> http://WWW.CAM.ORG/~mboukri/
>
> 73 de SM6FYQ/Ulf

        I purchased NEC4WIN almost a year ago, and just upgraded to
NEC4WIN95. NEC4WIN95 runs faster than NEC4WIN, and has some new
features which make it easier to build an antenna model, and display
its radiation pattern.

        I used NEC4WIN to design two yagi antennas for the 70 cm band.
One is a six-element array, and the other is a twelve-element array.
Both have a 50 Ohm input impedance. I recently built the six-element
array, and it seems to work as predicted. Its SWR curve indicates
that the antenna is resonant throughout the entire 70 cm band (as
designed), although the minimum SWR is about 1.3, which is higher than
the value of 1.12 as predicted by NEC4WIN. This is forgivable, since
SWR is a sensitive function of the antenna impedance. (No software
model is perfect.) I'm currently building the twelve-element array.

        NEC4WIN requires you to build a segmented `wire frame' antenna
description by entering the x-y coordinates for the ends of each
segment. This can be tedious; however, many (if not all) NEC based
products require you to do this. NEC4WI95 also limits you to 50
segments, but according the vendor, this limitation will be eliminated
in the future. (I'm currently modeling helical antennas, and need a
lot of segments. Hopefully this limitation will be lifted soon.)

        I'm happy with my purchase of NEC4WIN. It's worth the $30 I
paid for a supported version. It's perfectly good for modeling yagis,
verticals, dipoles or any other common antenna used by hams that can
be modeled as a wire frame. So for my needs (price range), I got what
I expected (paid for).

        I must qualify my assessment: I have not used any other
software packages -- and there a lots of them out there. If I were
doing antenna design for a living, I would shop around more.

-Dave, KA3QBQ

-- 
David Drumheller
Washington, DC