Topband: beverage antennas

[Milt Jensen, N5IA]

At 08:01 PM 8/22/1999 PDT, BARRY THOMPSON KG6O wrote:

>Does anyone have any experience or advice on Beverages that go up and down
hills,
>perhaps several times over their length?

Barry,
        My experience over the last 5 years is that in most cases you want
to follow the lay of the terrain.  The important part is to keep the
conductor an even distance above ground, whatever the spacing is that you
decide to use.
        However, if your terrain is very sharp, with steep narrow gullies,
I have found that the best way to install the antennas is go directly over
the gully as if it were normal terrain.  
        But, if the gully is more than a 1/4 wavelength wide and the depth
the same, that portion of the antenna will start acting like a normal
aerial high above ground.  To mitigate this effect, I install a
counterpoise ground wire, at normal ground level, underneath the Beverage
conductor.  
        I install ground rods at either end of this counterpoise wire, at
each side of the gully, with the counterpoise wire connected to them.
Galvanized steel wire is good for this application as it has a lower
velocity factor and more closely represents the velocity factor of the earth.
        My experience has been that an antenna which was over fairly wide,
deep gullies (ravines) and was having it's directional properties disturbed
could be made to perform normally by simply adding the counterpoise wire
for that distance.
        I hope this helps you and others.  Good luck with the 22 acres.

73 de Milt, N5IA  



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