Topband: beverages

Tom Rauch w8ji at contesting.com
Mon May 24 06:00:14 EDT 2004


> Would you not consider a circular polarized antenna
capable of diversity
> reception?

No.

Actually it will increase fading if it does anything at all.
You want a sharply and correctly focused antenna for minimum
fading, both for tranmsmitting and receiving. That is why BC
staions got away from using 5/8th wl verticals. The second
high angle lobe caused increased fading. When they shortened
the antenna enough to make that lobe disappear, the actually
called the antenna a "non-fading vertical".

V and H polarization, if you REALLY had circular
polarization, would do the same thing. Most antennas people
think or claim are circular are not.

> given even though you loose about 3 db in the process.
You buy it back
> in signal stability especially with multipath and
vehicular circumstances.

Direct wave is different than something arriving via the
ionosphere. The two are not remotely similar. Via the
ionosphere, the receiver would have to "vote". Transmitting,
multiple angles or rotating polarization would only add
fading.

73 Tom




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