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Helmut Wabnig[_2_] · November 16th 14, 08:11 PM posted to rec.radio.amateur.antenna

On Sat, 15 Nov 2014 21:38:10 -0000, wrote:

The following shows the effect on elevation pattern for a 1/2 wave
dipole antenna over ground at various heights for perfect, very good,
average, and extremely ground.

The important value to note is the elevation angle for the main lobe.

Generally for DX an elevation angle at or below 30 degrees is desirable
and for NVIS an angle above 60 degrees.

The elevation angles apply to any dipole type antenna, such as a G5RV,
OCF dipole, etc. but the absolute gain values will be quite different.

Also some types of dipoles have more lobes than the two of the 1/2
wave dipole; those lobes will still be elevated.

Perfect V good Avg Ext poor
Height gain @ elev gain @ elev gain @ elev gain @ elev
0.10 8.6 90 6.3 90 4.4 90 3.1 90
0.15 8.4 90 7.1 90 5.8 90 4.3 90
0.20 8.0 90 7.1 90 6.1 90 4.6 66
0.25 7.4 90 6.7 68 5.9 61 4.8 50
0.30 6.9 56 6.4 51 5.9 48 5.1 41
0.35 6.8 45 6.5 42 6.1 40 5.4 35
0.40 7.1 39 6.9 36 6.5 35 5.8 31
0.45 7.7 33 7.5 32 7.0 31 6.3 28
0.50 8.3 30 8.1 29 7.6 28 6.7 25
0.55 8.9 27 8.5 26 7.9 25 6.9 23
0.60 9.1 25 8.6 24 8.0 23 6.9 21
0.65 8.9 23 8.4 22 7.8 21 6.9 20
0.70 8.5 21 8.0 20 7.6 20 6.8 18
0.75 8.0 19 7.7 19 7.3 18 6.7 17
0.80 7.6 18 7.4 18 7.2 17 6.7 16
0.85 7.5 17 7.4 17 7.2 16 6.7 15
0.90 7.6 16 7.5 16 7.3 15 6.9 15
0.95 7.8 15 7.7 15 7.5 15 7.1 14

Special note:

Most people understand that the results of an antenna analysis program
reflect the material used to construct the antenna and the type of
ground, if any, used for the analysis, are an approximation, and are
not accurate to 27 decimal places.

Further, most people also understand that absent them being a part of
the model used for the analysis, objects in the near field of the antenna,
such as, but not limited to, 20 foot prision walls, blimp hangers,
skyscrapers, a deluge of biblical proportions, giant sequoia trees,
hovering 2 mile wide alien spacecraft, hords of locusts, large gold
deposits under the antenna, battles between Autobots and Decepticons,
beached aircraft carriers, and stadium domes may well effect the
actual antenna perfomance.

Your mileage may vary, void where prohibited.

Any spelling mistakes in this article are all entirly my fault. Any grammer
errors spotted in this article were put there because I could.

I have seen people talking about NVIS antennas for DX.

w.

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