> However the elevation pattern and gain using real ground
> shows virtually no difference with 0,2,4, and 8 radials.
> The source impedance jumps from highly reactive with no
> radials to 50 ohms mostly resistive using two radials and
> lowers a bit using 4 and 8 radials.
> The pattern and gain being nearly identical no matter how
> many radials are use (including none) has me wondering if
> I have something wrong in my model?
Models don't do as well as people imagine for horizontal
wires near ground. The model treats the earth like a big
homogeneous mass with uniform characteristics.
Now if the radials are high enough, say 1/4 to 1/2 wave
above ground, things are OK. But when we put a wire very
close to earth things fall apart. If your model is showing
no difference between zero and four radials or showing four
radials no different than 30 or 60 radials something is
You'll certainly make contacts with only two or four radials
elevated radials, but more than half the power will be lost
in the fields concentrated in the lossy earth near each
radial. You'll also have a hard time decoupling the feedline
from the antenna, so you'll have significant common mode
currents on the feeder to deal with.
None of this means the antenna won't work, and some people
with vivid imaginations manage to convince themselves some
very poor systems work well, but the fact is it won't be a
good system unless you have ten or twenty radials minimum.
And when you get the ten or twenty radials, they might as
well be on the ground as elevated.
The sole exception to this is ground that is a near- perfect
insulator or a near-perfect conductor, or if the radials are
a large distance in fractions of a wavelength above the
lossy media. But even in those cases the feedline really
needs decoupled because the antenna is neither perfectly
balanced or perfectly unbalanced.
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