Tom W8JI said
>As far as I know the low angle
>signal is affected by things at a pretty good distance, out
>to perhaps 2 WL or more.
>
NCJ ran a feature by Al K3LC in the Sep/Oct 2006 issue showing how the
gain of a vertical antenna at various elevation angles depends on ground
away from the antenna. The results showed that ground at 14 wavelengths
away (7,504ft on 1.835 KHz) is important for a 1 degree elevation angle.
Ground at 2.7 wavelengths away (1,448ft) is important for a 5 degree
elevation angle. Ground at 1.4 wavelengths away (750ft) is important for
a 10 degree elevation angle. Ground at 0.7 wavelengths away (375ft) is
important for a 20 degree elevation angle.
As Tom said, your radials affect your efficiency - not the low angle
gain. The low angle gain is determined by ground a lot farther away than
a typical radial system.
Carl K9LA
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