On Thu, 20 May 2004 19:49:28 -0700, Roy Lewallen
wrote:

Be careful about making generalizations about this. The position of the
peak current depends on frequency and the ground characteristics. I
believe it's also a function of the height of the vertical. In some
cases there's no real peak at all, but an exponential-looking decay of
current from the base of the vertical outward. This, incidentally, was
experimentally measured and documented by Brown, Lewis, and Epstein in 1937.

Roy Lewallen, W7EL


Interesting. I went back to the model and took a look at the current
in the radials.

My model was a 1/2-wave monopole using 120 1/2-wavelength buried
radials. The frequency was 3.6 MHz.

EZNEC (Version 4) reported the peak radial current at about
0.41-wavelength from the base of the antenna. I made two runs. One
using poor ground and one using average ground. The peak current
location was the same in both.

This still leads me to believe that the difference in gain reported
between what Richard had modeled and I found (0.1 dB vs 1.0 dB) is due
to the length of the radials.

In ether case adding that much wire (15,840 feet) for so little gain
sure doesn't seem worthwhile.

73
Danny, K6MHE