piramid.nec

zip contains tool for Antenna Modelling with examples

CM Piramid.nec 
CE

SY Lx=6.92	' To resonate this structure

GW 1 7 0.0 0.0  18.0 -Lx -6.6  8.0  .0008
GW 2 7  Lx -6.6  8.0  .2 0.0  18.0  .0008
GW 3 7 -Lx -6.6  8.0  Lx -6.6  8.0  .0008
GW 4 7 0.0 0.0  18.0  Lx  6.6  8.0  .0008
GW 5 7  .1  .5  18.0 -Lx  6.6  8.0  .0008
GW 6 7 -Lx  6.6  8.0  Lx  6.6  8.0  .0008
GW 7 1  .2 0.0  18.0  .1  .5  18.0  .0008
GE 1

GN 2 0 0 0 13  0.005
EX 0 7  1  0  1.0 0.0
FR 0 1 0 0 3.75 1
EN