[amsat-bb] nec2

[Apostolos Kefalas]

Hello Roy,

I am a casual user of nec2 but here what I have done:

1. Edit GM card by moving Z to 3 
2. Edit GE card and select "Ground present, Structure reflection"
3. Edit RP card and decrease "points in theta" to 31. Also decrease 
"increment theta" to 3
4. Add a GN card and select "Sommerfeld/Norton"

Hope this helps

Apostolos
SV1LJJ



On Fri, 2019-11-22 at 19:45 -0500, Roy Dean via AMSAT-BB wrote:
> Is anybody on this list a power (or even casual) user of nec2?   I've
> been
> tinkering with xnec2c, and am attempting to model AA4TX's parasitic
> lindy
> antenna (70cm) as a check (Tony provided gain plots in his paper).
> 
> However when I plot gain, all I get is the standard donut pattern
> (vert
> polarization), and sort of modified donut when viewing RHCP.
> 
> .nec file is below  (apologies for formatting).   Thanks in advance
> to
> anybody that can offer insight.   The learning curve for this
> software is
> steep.  (not sure if Steve Conklin is on this list - but the below
> nec data
> was built off of his 2m satellite yagi model)
> 
> --Roy
> K3RLD
> 
> CM AA4TX 70cm parasitic lindy antenna design
> CE End Comments
> GW     1    25   0.00000E+00  0.00000E+00 -1.57000E-01  0.00000E+00
>  0.00000E+00  1.57000E-01  1.90500E-02
> GW     2    25  -1.29000E-01  1.03000E-01  7.50000E-02  1.29000E-01
>  1.03000E-01 -7.50000E-02  3.25000E-03
> GW     3    25   1.03000E-01  1.29000E-01  7.50000E-02  1.03000E-01
> -1.29000E-01 -7.50000E-02  3.25000E-03
> GW     4    25   1.29000E-01 -1.03000E-01  7.50000E-02 -1.29000E-01
> -1.03000E-01 -7.50000E-02  3.25000E-03
> GW     5    25  -1.03000E-01 -1.29000E-01  7.50000E-02 -1.03000E-01
>  1.29000E-01 -7.50000E-02  3.25000E-03
> GM     0     0   0.00000E+00  0.00000E+00  0.00000E+00  0.00000E+00
>  0.00000E+00  0.00000E+00  0.00000E+00
> GE     0     0   0.00000E+00  0.00000E+00  0.00000E+00  0.00000E+00
>  0.00000E+00  0.00000E+00  0.00000E+00
> FR     0    20     0      0  4.36500E+02  1.00000E-01  0.00000E+00
>  0.00000E+00  0.00000E+00  0.00000E+00
> EX     0     1    13      0  1.00000E+00  0.00000E+00  0.00000E+00
>  0.00000E+00  0.00000E+00  0.00000E+00
> RP     0    99    99   1000  0.00000E+00  0.00000E+00  5.00000E+00
>  5.00000E+00  0.00000E+00  0.00000E+00
> EN     0     0     0      0  0.00000E+00  0.00000E+00  0.00000E+00
>  0.00000E+00  0.00000E+00  0.00000E+00
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