elevatrad.nec

zip contains tool for Antenna Modelling with examples

CM This illustrates a vertical antenna with elevated radial
CM system. At 0.0001 wavelength, the height is about as low
CM as NEC can model accurately. 
CM Calculated performance does largely depend on the position
CM of the excitation source related to the radiator lenght,
CM the distance from the radial wires connection and their 
CM lengths.
CE

SY freq=1.832
sy WL=299.8/freq, M=WL/1000	' Minimal NEC segment length

sy len=35.56			' Length
sy radh=0.01778, radl=39.624	' Radial height, length

GW 1 3  0.0 0.0 radh	 0.0   0.0   radh+3*M 0.0012941	' Short wire for excitation source
GW 2 70 0.0 0.0 radh+3*M 0.0   0.0   len      0.0012941	' Rest of radiatior.

GW 0 55 0.0 0.0 radh     radl  0.0   radh     0.0012941	' Radial wires
GW 0 55 0.0 0.0 radh     0.0   radl  radh     0.0012941
GW 0 55 0.0 0.0 radh     -radl 0.0   radh     0.0012941
GW 0 55 0.0 0.0 radh     0.0   -radl radh     0.0012941
GE 0

EX 0	1	2	0	1	0
GN 2	0	0	0	13	5.e-3
FR 0	1	0	0	freq
EN