Here are the results from the analysis of a 26 radial system.

0.6 m -- Radial Z = 37.3 - j 28.1 -- Efficiency 15%
0.8 m -- Radial Z = 30.5 - j 21.0
1.0 m -- Radial Z = 26.2 - j 16.9
1.2 m -- Radial Z = 23.2 - j 14.2
1.4 m -- Radial Z = 20.9 - j 12.4
1.6 m -- Radial Z = 19.1 - j 11.1
1.8 m -- Radial Z = 17.6 - j 10.1 -- Efficiency 21.0%
2.0 m -- Radial Z = 16.2 - j 9.4
2.2 m -- Radial Z = 15.1 - j 8.8
2.4 m -- Radial Z = 14.0 - j 8.4
2.6 m -- Radial Z = 13.0 - j 8.0
2.8 m -- Radial Z = 12.1 - j 7.7
3.0 m -- Radial Z = 11.3 - j 7.4
3.2 m -- Radial Z = 10.4 - j 7.1 -- Efficiency 24.5%
3.4 m -- Radial Z = 9.7 - j 6.8
3.6 m -- Radial Z = 8.9 - j 6.5
3.8 m -- Radial Z = 8.2 - j 6.2
4.0 m -- Radial Z = 7.5 - j 5.8
4.2 m -- Radial Z = 6.9 - j 5.5
4.4 m -- Radial Z = 6.4 - j 5.1
4.6 m -- Radial Z = 5.8 - j 4.7
4.8 m -- Radial Z = 5.4 - j 4.3
5.0 m -- Radial Z = 5.0 - j 3.9 -- Efficiency 27.8%
5.2 m -- Radial Z = 4.6 - j 3.5
5.4 m -- Radial Z = 4.3 - j 3.1
5.6 m -- Radial Z = 4.0 - j 2.7
5.8 m -- Radial Z = 3.7 - j 2.3
6.0 m -- Radial Z = 3.5 - j 2.0
6.2 m -- Radial Z = 3.3 - j 1.6
6.4 m -- Radial Z = 3.1 - j 1.3
6.6 m -- Radial Z = 3.0 - j 0.9
6.8 m -- Radial Z = 2.9 - j 0.6
7.0 m -- Radial Z = 2.8 - j 0.3
7.2 m -- Radial Z = 2.7 + j 0.01
7.4 m -- Radial Z = 2.6 + j 0.3
7.6 m -- Radial Z = 2.6 + j 0.6
7.8 m -- Radial Z = 2.6 + j 0.9
8.0 m -- Radial Z = 2.5 + j 1.1 -- Efficiency 31.1%
.
.
10.0 m -- Radial Z = 3.0 + j 3.3 -- Efficiency 32.6%

Where I have shown the efficiency as sky wave power
out. The input impedance is that of all radials, so for
a single radial the input Zr must be Ztr * 26.

===========================================
Frank,

The input impedance of 26 radials is NOT equal to all 26 connected in
parallel. There is a non-linear relationship between the number N and
input impedance because they share the same volume of soil at least
when they are short.

For 26 radials the resonant effects have disappeared which I cannot
explain. Yet attenuation is the same, Zo converges on Zin at
approximately 8 or 10 metres as before.

You appear to have automated the results. Can you do a large number
of radials, say around 100, from 0.4 to 8.0 metres?

And can you do a small number of radials such as 6 or 8, from 0.4 to
8.0 metres?