[antennaware] vertical modelling

[Gerald Schmitt]

Arie,

I have access to NEC4 and it indeed does handle the buried and elevated
radials properly. I also have an interest in shortened verticals. If you
would like
to send me a NEC input file or even better an EZnec input file I will be
happy
to model it for you. The NEC4 code cannot be shared but I am willing to
run
the problem. 

Incidentally the results you cite seem reasonable based upon my
experience
with inverted L designs.

				73 Jerry

On Mon, 18 Jun 2001 12:19:39 +0200 Arie.Voors@ict.nl writes:
> 
> 
> 
> For a periode of time now I am trying to modell a vertical with a 
> two spoke top
> hat (80 m dipole) and a radial ground screen.
> 
> The actual (burried) ground screen consists of about 20-30 copper 
> wires with
> lengths between 1/8 and 1/4 wavelengt;
> some without, but mostly with one or two copper ground stake pipes 
> (5 meters
> long).
> 
> The measured impedance is about 45 + j 400 ohms.
> 
> The modelled antenna, using a 20 radial ground screen elevated 20 cm 
> above
> ground, gives me an impedance of 22 +j 150 ohms
> 
> I can not beleave that my ground (screen) has such a 'big' impedance 
> of about 23
> ohms.
> 
> My modelling of antenna systems, not using a ground screen, works 
> very well.
> 
> The question is, is it possible with nec-2 to model such a vertical 
> antenna
> system
> by using a ground plane elevated above ground, or do I have to use 
> nec-4 ?
> 
> Is it possible for 'normal' people, not connected to any official 
> company or so,
> to get a PC based nec-4 executable ?
> 
> Another question is, if there are people who have succecfully 
> modelled a
> vertikal antenna with
> a burried ground screen using nec-2 ?
> 
> If so, is it possible for me to recieve a copy of this model ?
> 
> Thanks in advance,
> 
> Arie.
> 
> 
> 
> --
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> Administrative requests:  antennaware-REQUEST@contesting.com
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> 

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