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 NEC-4 on gnd radias
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vk3pa
Deceased

Australia
1714 Posts

Posted - 31 Jan 2009 :  01:28:38 AM  Show Profile  Visit vk3pa's Homepage  Reply with Quote
taken for 160m 1/4 wave vert es radials
above ground =6 inches
NEC-4.

Soil Type Gain TO Angle Source Impedance
dBi degrees R +/- J X Ohms

4-radials: 31 wires; 61 segments
Very Poor........ -1.90..... 27.............. 41.91 + j 18.38
Poor -0.33 25 40.27 + j 22.38
Good 0.66 22 41.28 + j 23.89
Very Good 2.45 17 42.26 + j 21.04

8-radials : 55 wires; 109 segments
Very Poor -1.47 27 37.49 + j 3.69
Poor 0.03 25 36.84 + j 6.82
Good 1.01 22 37.99 + j 8.78
Very Good 2.81 17 38.89 + j 9.56

16-radials: 103 wires; 205 segments
Very Poor -1.34 27 35.91 - j 1.80
Poor 0.09 25 36.08 + j 0.89
Good 1.06 22 37.37 + j 2.61
Very Good 2.92 16 37.91 + j 4.36

32-radials: 199 wires; 397 segments
Very Poor -1.29 27 35.09 - j 3.55
Poor 0.09 25 35.69 - j 1.05
Good 1.04 22 37.24 + j 0.48
Very Good 2.92 16 37.83 + j 2.46

64-radials: 391 wires; 781 segments
Very Poor -1.23 27 34.36 - j 3.63
Poor 0.10 25 35.24 - j 1.36
Good 1.02 22 36.97 - j 0.10
Very Good 2.91 16 37.91 + j 1.99

128-radials: 775 wires; 1549 segments
Very Poor -1.12 27 33.81 - j 3.04
Poor 0.17 25 34.80 - j 0.95
Good 1.03 22 36.51 + j 0.04
Very Good 2.87 16 37.97 + j 1.89

below ground 6 inches..
NEC-4.

Soil Type....... Gain........TO Angle.......Source Impedance
...................... dBi...........degrees........R +/- J X Ohms

4-radials: 32 wires; 62 segments
Very Poor.......... -4.37.......27............... 87.04 + j 25.31
Poor...................-2.49.......25................72.45 + j 19.47
Good...................-0.71.......23...............60.96 + j 20.42
Very Good............2.10.......17................47.34 + j 14.52

8-radials: 56 wires; 110 segments
Very Poor -3.11 28 65.90 + j 18.09
Poor -1.51 25 58.63 + j 15.18
Good -0.04 23 52.43 + j 15.94
Very Good 2.60 17 44.34 + j 12.60

16-radials: 104 wires; 206 segments
Very Poor -1.61 28 52.71 + j 12.43
Poor -0.16 25 49.71 + j 12.18
Good 0.86 23 46.79 + j 12.83
Very Good 2.79 16 42.20 + j 11.18

32-radials............:200 wires;................. 398 segments
Very Poor.............-1.32.......27............... 44.89 + j 7.54
Poor..................... 0.17......25................43.44 + j 9.55
Good....................1.12.......22............... 42.67 + j 10.46
Very Good..............2.94......17................40.48 + j 10.03

64-radials: 392 wires; 782 segments
Very Poor.............-1.19.......27................40.68 + j 4.11
Poor..................... 0.32.......25................39.43 + j 7.08
Good......................1.26...... 22................39.73 + j 8.50
Very Good..............3.05....... 17.................39.06 + j 9.07

128-radials: 776 wires; 1550 segments
Very Poor.............-1.12.......28...............38.60 + j 2.18
Poor..................... 0.17.......25...............37.32 + j 5.29
Good......................1.03.......23...............37.91 + j 6.99
Very Good........... 2.87....... 17................. 37.94 + j 8.27 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
therefore looking at the chart the min is 32 radials under gnd es max is 64 radials.. if we look at 124 we see a decrease in gain..
So as we add radials up to 64, we notice gain increases es rad angle lowers!!
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

vk3pa
Deceased

Australia
1714 Posts

Posted - 31 Jan 2009 :  01:48:40 AM  Show Profile  Visit vk3pa's Homepage  Reply with Quote
We also notice at 124 rad. we have a much lower take off angle (17deg.)..
We have not looked at the secondry take off angle ,possible at 160 deg..this is not a gud angle for DX as local stations will tend to over ride DX stations, off cause this is for a sigal vertical, when we add other verticals 2/3 or 4 as in my case things can improve as we sw verticals around hi angle interferance can be removed even if we have to switch bach for TX'n..
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