Carl:
NM7M has steadfastly maintained that skews, while demonstrable, are
rather small (just a few degrees, far too small to be readily measured
by most of us), but many have noted apparent arrival directions widely
different from great circle bearings. For example, VK0IR was noted on
the west coast as coming in from the west or even more northerly, on
both 80 and 160, although its SP direction was SSW. The sidelobe
response of a Beverage to horizontal polarization may well explain why
received signals here have often appeared to be coming from widely
skewed directions.
Garry, NI6T
Carl and Vicky wrote:
>
> Carl KM1H (you certainly have a great first name),
>
> I?m sure a Beverage does have at least 20dB of rejection to horizontal
> polarization on the forward vertically polarized lobe.
>
> But I wasn?t talking about that. I was talking about the horizontally
> polarized side lobes that don?t seem to be that far down in amplitude
> from the forward lobe - my cursory modeling shows the horizontally
> polarized side lobes to be only 10-15dB or so down from the vertically
> polarized forward lobe (seems to depend on Beverage length).
>
> Suppose you have two Beverages - one is pointed to the NE and one is
> pointed to the SE. If a signal is coming in from the SE but is
> predominantly horizontally polarized, it just may be strongert on the NE
> Beverage than on the SE Beverage.
>
> How about some modeling from others on this? If I?m off base here, let?s
> hear about it. Does anyone have any polarization measurements on
> Beverages?
>
> Carl K9LA
>
> --
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--
Garry Shapiro, NI6T
Visit the Northern California DX Club home page:
http://www.ncdxc.org
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