G8JNJ
432 MHz Mixed Mode Helical Antenna NEC Model


G8JNJ 432 MHz Mixed Mode Antenna ModelCM Helix over perfect groundCM Illustrates use of GH (helix) input CM Illustrates use of GM (move wires) input CE SY f=432 'Input Frequency MHz SY k=308.756 'Input Velocity constant ~300 Mm/s SY w=k/f 'Calculate Wavelength in space SY hw=0.5*w 'Calculate Half wavelength in space SY t=3 'Input Number of helix turns SY ts=18 'Input Segments per helix turn SY n=t*ts 'Calculate Segments total SY wl=0.5 'Input Antenna height in wavelengths SY l=wl*w 'Calculate Antenna height in meters SY s=l/t 'Calculate Turn spacing in meters SY r=sqr(hw*hws*s)/2/PI 'Calculate Helix radius in meters SY d=.0025 'Input Wire radius in meters SY h=2 'Input Height above ground in meters GH 1 n s l r r r r d GM 0 0 0 0 0 0 0 h 0 GE 1 LD 5 0 0 0 58000000 'copper GN 1 EK EX 0 1 n/2 0 1. 0 0 FR 0 0 0 0 f 0 EN REFERENCES
