Topband: Another DXpedition 160 Vertical Idea

Tom Rauch w8ji at contesting.com
Fri Jan 28 19:43:21 EST 2005


Up to half of the far field signal strength is derived from
the ground reflected wave.>>

It seems to me if you are talking only about reflection gain
it's roughly 6dB, not 3dB. That's a 4:1 power ratio. What
would normally be lost or absorbed could be reflected and
added to the desired radiation. You lose the addition to
radiation above the earth's surface when it all is absorbed
in the earth.

It can be more than 6dB when we consider additional things
like nearfield losses.

It could vary widely with soil conditions and the antenna
style.

If ground independent half-waves with no radial systems are
so good, why have they not become standards in broadcasting?
Fact is it is cheaper and less work to just use a good
ground system and a much shorter antenna, and it works just
as well or better.

73 Tom



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