[TowerTalk] Verticals

[Jim Lux]

At 09:49 AM 12/24/2006, D. Scott MacKenzie wrote:
>I use MMANA quite a bit - it also has an implementation of NEC-2.  It works
>well, fast, and gets me in the ballpark.  I use it to see whether an idea
>works, or to see what sort of changes I need to make.
>
>The best part of it - is that it is free.
>
>I would love to do a comparison between several different pieces of software
>and see which one models the best, or gets accurate results....anyone have
>any simple and more complicated models that they would like to compare?  It
>might make a good article for QST or QEX.....


There is already such a comparison. It's in one of the antenna compendiums.

Basically, all programs that do method of moments work about the same 
(many of them actually use the identical NEC engine underneath).  The 
differences are in convenience of user interface, and in some "addons".

NEC4 does produce better results than NEC2. It has better arithmetic 
codes, and, uses a slightly different way of representing the current 
distribution in each segment which has better numerical conditioning 
(i.e. roundoff doesn't bite quite so hard).

  NEC4 also does much better at modeling wires close to ground.

You definitely want to use the Sommerfield-Norton ground for either.


>Scott, aka KBOFHP
>
>-----Original Message-----
>From: towertalk-bounces at contesting.com
>[mailto:towertalk-bounces at contesting.com]On Behalf Of Bill Turner
>Sent: Sunday, December 24, 2006 12:34 PM
>To: Towertalk
>Subject: Re: [TowerTalk] Verticals
>
>
>ORIGINAL MESSAGE:
>
>On Sun, 24 Dec 2006 11:32:05 -0500, "D. Scott MacKenzie"
>  <kb0fhp at comcast.net> wrote:
>
> >THere is also a free - not limited in any fashion modeling program called
> >MMANA.  Very good, effective and accurate.
> >
> >Found at http://mmhamsoft.amateur-radio.ca/
>
>------------ REPLY FOLLOWS ------------
>
>Hadn't heard of that one but I'll give it a try. If it's as good as
>his MMTTY program for RTTY, it will soon take over the known universe.
>:-)
>
>73, Bill W6WRT
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