RadioBanter - View Single Post

[email protected] · July 19th 06, 03:59 PM posted to rec.radio.amateur.antenna

wrote:
96 radials, 7MHz, antenna height 10.72m. Soil 500ohm*m, permittivity
13\

Radials and antenna 1.024mm (18AWG), radials 3mm deep(surface)
Radial Length, %Efficiency

2m, 93.19%
3m, 93.83%
4m, 92.47%
5m, 86.01%
6m, 80.39%
7m, 85.92%
8m, 89.06%
9m, 89.59%
10m, 88.22%
11m, 85.99%
12m, 85.51%
13m, 86.67%

I sure wouldn't fully trust a NEC based program for buried wires, let
alone a program someone just threw together without any verification at
all. This is especially true when the answer looks so weird. Standing
waves on a wire in contact with soil making efficiency go down as the
wire length is increased? Give me a break!

I seriously doubt any vertical antenna would be even close to 93%
efficient with 7 foot long buried radials.

A precise looking answer that gives us a warm fuzzy feeling makes the
answer a good one, no matter how wrong the answer is.

73 Tom