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Old August 3rd 06, 02:40 AM posted to rec.radio.amateur.antenna
Frank's Frank's is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 56
Default Radiating Efficiency

Frank,

Thank you for the above.

Can you do 36 radials from 0.6 to 8.0 metres in increments of 0.2
metres?

Must be the same input data as before :- F = 8.07 MHz, Ground =
150,16 Radial diameter = 1.64mm, Depth = 25mm.


Reg,

Here are the results from the analysis of a 26 radial system.
All dimensions and parameters are the same as for the single
radial antenna as you defined above:

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