[amsat-bb] Re: 70cm Yagi and AO-51

Edward Cole kl7uw at acsalaska.net
Tue Jan 1 10:41:54 PST 2008

3-dB down each way.  For satellite reception this is not too 
bad.  However, some satellite's circular pol (CP) signals are 
elliptical (have some linear component) if they have a squint angle 
with the ground station.  Thus the use of the linear-pol Arrow and 
the "Arrow Wave" works quite well.

In the past being able to switch sense in CP helps because satellite 
squint can result in a reverse of polarity sense.  Then you have 
AO-51 that utilizes opposite sense CP on different frequencies to 
improve isolation in the onboard receivers.

HNY & 73,
Ed - KL7UW

At 06:54 AM 1/1/2008, Andrew Rich wrote:
>If I have this correct.
>1. LHCP recieved on a RHCP can knock your signal down by some 20dB
>2. LHCP matched with LHCP will result in a good signal.
>So how does a linear antenna equate when receiving a circular signal ?
>And the other way around, a circular receiving a linear signal ?
>Andrew Rich VK4TEC
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Ed - KL7UW
  BP40IQ   50-MHz - 10-GHz   www.kl7uw.com
144-EME: FT-847, mgf-1801, 4x-xpol-20, 185w
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