Topband: Cone of Silence

[K9AY]

Sloping the ends of a Beverage is one of many antenna ideas that seem
plausible, but do not hold up under further analysis.

I know Tom W8JI has explained this before, but I'll try again...

It doesn't matter whether you slope the last 50 feet of the Beverage or
continue 40 feet of it horizontal and run 10 feet straight down. Either way,
you have 10 feet of vertical distance.  A vertically-polarized wavefront
arriving from the side will 'see' only the 10 foot high vertical component
of the sloped end -- the same as with a straight vertical wire.

73, Gary
K9AY


> Don and Tom,
>
> My understanding of the operational characteristics of the Beverage
antenna
> is that the use of sloping terminations eliminates the requirement of
> special efforts to cancel the reception of vertically polarized signals in
> ALL directions that would be picked up by a few feet of vertical
termination
> wire off a pole.
>
> I understand that the vertically polarized signals from the "front" of the
> antenna will be received equally well by the sloping termination of the
> antenna or a vertical termination wire.  BUT, the sloping termination
> continues the characteristic of the Beverage antenna, in that it
> predominantly responds to signals in the plane of the axis of the antenna.
>
> The vertical termination wire allows vertically polarized signals from ALL
> directions to degrade the performance of the Beverage antenna.  I disagree
> that the quantity of signal induced in this manner is not detrimental to
> performance.  All you have to do is insert a short piece of wire into the
> antenna jack of your receiver to know how much signal that short piece can
> deliver.
>
> I believe that small amount of signal from unwanted directions can, in
many
> instances, totally obsure a weak signal from the desired direction.
>
> Comments?
>
> Milt, N5IA