At 05:59 PM 7/5/2005, Doug Rehman wrote:
>Bill-W4BSG wrote:
>
> >I'm about to add a
> > vertical for just that reason, but I'll keep my droopy Yagi.
>
>Better make that a horizontal loop. Using a vertical will cost you 20dB of
>cross polarization loss when communicating with others using horizontal
>yagis- at least on local communications.
But for close in communications, the 1/r^2 spreading loss will be much
less, and might make up for the cross polarization. If you could work,
say, ZL from W6 on 100W with a horizontally polarized antenna (a path of
some 10,000 km), then even with a 20dB hit from the antenna, you could work
anything within 1000 km. But that's a gross oversimplification, and I doubt
that polarization of the two ends of the link has a lot to do with HF
propagation.
I'd also not want to bet much on polarization purity of any ham antenna,
horizontal or vertical, and particularly not after it has propagated much
beyond line of sight.
The polarization of "your end" of the link has a fairly strong effect on
the elevation pattern of the antenna.
Anyway, I suspect that there are a lot of other factors that would be much
bigger effects on a HF link (of whatever distance, other than strictly near
field coupling) than the polarization (or lack of same) on the radiated waves.
Now, on 6m... you're getting to where the propagation can be really
weird. You also have things like terrain multipath to worry about.
>Doug
>K4DDR
>
>
>_______________________________________________
>
>See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
>Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with
>any questions and ask for Sherman, W2FLA.
>
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_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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