Topband: Two Wire Beverage Question
Herb Schoenbohm
herbs at vitelcom.net
Thu Dec 25 12:01:13 EST 2003
Tracey,
As I understand the principles of the Beverage both conductors should be
parallel to the ground to work properly. The good operation of a
Beverage depends on a process known as wave tilt.
"When a vertically polarized signal travels over the surface of an
imperfect conductor such as the earth, the wave front leans forward in
the direction of the propagation. this is caused by the slower
propagation of the earth. the amount of forward tilt depends on the
frequency of the rf wave and the characteristics of the surface over
which the wave is traveling. At the low frequencies at which the
Beverage is used the wave tilt is approximately proportional to the
square root of the product of the frequency and coil resistively. As
the resistance of the surface is increased, the wave travel along the
surface is reduced and a greater wave tilt results." T.O. 31-1-141-15
U.S. Army Publication
They also add that..... "the wave antenna operates in conjunction with
ground to produce a vertically polarized radio wave. However, because
of the forward tilt, there is horizontal component of the electrical
field, and it is not exactly in phase with the vertical component.
Therefore, the resultant polarization of the radiated wave is elliptical."
73
Herb Schoenbohm, KV4FZ
Tracey Gardner wrote:
>Just a quick question on the two wire Beverage as per Jeff Parker, KA1GJ
>
>http://members.cox.net/kb1gw/KA1GJ-Beverage.htm
>
>Am I correct in thinking that using two wires vertically spaced rather than
>horizontally, wouldn't work, due to cancellation?
>
>73s Tracey
>
>
>
>
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