[amsat-bb] Polarity

Steve Kristoff skristof at etczone.net
Sat Jan 9 17:20:57 UTC 2016


Well, the cosine of 45 degrees is actually 0.707. I suspect that the article 
is implying that the loss is linear. Since 45 degrees is half of 90 degrees, 
then you lose half the power, or -3dB.
Following that logic, at 22.5 degrees you'd half one-fourth the power 
or -6dB, etc.

I have no idea if the article is correct, but the cosine of 45 degrees is 
0.707

Steve AI9IN

----- Original Message ----- 
From: "Robert Bruninga" <bruninga at usna.edu>
To: "amsat bb" <amsat-bb at amsat.org>
Sent: Saturday, January 09, 2016 12:05 PM
Subject: Re: [amsat-bb] Polarity


>> We all know that [matched polarity] = Zero db loss from cross
> polarization.
>> And then in theory, the "Infinite loss"  when cross polarized...
>> [Pracically],it's more like 30 to 40 db or so [ or much less in the
> presence of reflections]
>> Now does anyone know of a chart ... for every degree of something really
> is?
>> Like 45 deg is 3 db down,  50 deg =? 55 deg =?  etc.
>
> The cosine table works for all angles..  The cosine of 45 degrees is 1/2
> which is -3 dB etc...
>
> Bob, Wb4APR
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Steve Kristoff
skristof at etczone.com

"A few chords strummed on a ukulele, enough to please a few others beside 
yourself, does more good in this world than the combined efforts of all the 
financiers and politicians that ever lived." - Frank Littig, Littig's New 
Harmony Self Instructor Chords for Ukulele, Banjuke or Taro Patch Fiddle, 
Chart Music Publishing House, Chicago, Illinois, 1924 



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