[BC] NEC Groundwave Calculations

[Richard Fry]

NEC-2 and NEC-4 both can calculate the surface wave field (groundwave) of a 
monopole radiator in fairly close agreement with the FCC's groundwave 
propagation charts.

The link below shows one comparison using NEC-2D for a 1/4-wave monopole 
using an elevated radial system (avoids the limitation that NEC-2 cannot 
model buried conductors).

The biggest issue with calculation vs. reality probably is accurate 
knowledge of earth conductivity along the path.

NEC is very good at calculating radiation patterns for a given set of 
mechanical/electrical conditions, but what happens to that radiation after 
it is "launched" is another matter altogether.

http://i62.photobucket.com/albums/h85/rfry-100/PropChart1700kHz.gif

RF