[Antennas] Antenna Modeling

[Chris Trask]

>
> From time to time I do some analysis with a NEC engine based antenna
> modeling program.  I'll not mention specifically which one.  The results I
> get with it are satisfactory.  I do have some problems with input.  I find
> the input system to be awkward.  That may be because I am used to CAD.
>
> One of the input systems works by graphically creating lines with a mouse
in
> a window.  Invariably they then need a lot of tweaking through adjusting
> geometric coordinates in data input mode.  The other method is more
strictly
> geometric coordinate input.  I have not yet advanced to using tables of
> data.
>
> I am looking for other, free or low cost programs with a different
> input/data creation system.  I do not know what all may be available.  It
> might be good to be able to import models from CAD... .dwg, .dxf, etc.
>
> A graphical interface suits me better than data input.  I'm more visually
> oriented than mathematically.  I can handle the data input, but it is a
bit
> tedious for me.
>
> My use is typically for wire antennas.  One thought is that I could more
> easily input via CAD and import into a modeling program.  Are there other
> thoughts to be shared on various modeling programs?
>

    I was one of the very first users of the NEC algorithm when it first
became available in the form of a programme called AMP.  It ran on an IBM
360/370 mainframe and would use as many as six full tape drives to store the
intermediate results of the matrix decomposition.  Input was by way of
punched cards.  At that point in time, input terminals with keyboards were
still in the development stage using a package called APL.  AMP was provided
to Penn State by way of the Rome Air Devlopment Center, or so I understood
at the time.

    I got used to using the tabulated form of geometry input using AMP, and
I still use the DOS version of EZNEC as it's in the format that I'm used to.
There's a Windows version of EZNEC, but I have yet to have the opportunity
to see it first-hand, so I can't tell you if it's a graphic or tabulated
data input.


Chris

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