Antenna Software Options

Modelling Software

Windows

On Windows there are 3 good choices of Free (!) antenna modellers.

My order of preference of these products is

• 4nec2
• MMANA-GAL
• EzNECPro

'Solve'

You have a design... say a 1/4 wave verticle, which is nearly resonant... then 4nec2 and MMANA-GAL can automatically 'adjust' some elements so the SWR/Gain/Front-to-Back etc is met.

Sadly this functionality is not available free for EzNecPro. Instead you need to buy AutoEZ.

Tranformers/Baluns

These are tricky to modle in 4Nec2, and MMANA-GAL; But easy in EzNecPro.

Linux

NEC2 is available - and I do see some rather old looking Nec visualisation software.

Mac

There is a nice Cocoa program called cocoaNEC It has two mechanisms to operate - the 'spreadsheet' look like 4nec2/mmana/ezNecPro and a programming model style.

Tips/Hints

I usually built the same antenna using two different Software packages. If they both yield similar results then I will proceed.

Why use two packages ?? 4Nec2 has some strange 'Ground' issues - MMAMA-GAL seems a little strange when using Load/Phasing. EZnecPro has no 'optimize' so best use another package to get very close, and then use that package.

4Nec2

Variables

Try as much as you can to use Variables.

SY X=6         'Length - Optimiser/Evolve can change this
SY SIDE2=3.5  'Side2 - This can not be changed in Optimiser/Evolve

When you hard code a value - you are unable to vary that value in the Optimizer/Evolve process.

Optimize or Solve ?

If you have a model, and you want to find the best SWR ... then use the Calculate/Start Optimizer. I however prefer to use Evolve - it may take a little longer but you can see the various steps the algorithm went through to get to the final result.