Linear vs Circular Polarization
Hi Everyone,
I'm working on building a pair of crossed yagis for 2m and 70cm, and I have some questions. I apologize if this has been discussed before, but I couldn't find answers online so I was hoping you all could help me out.
First, it seems easiest to me to build an antenna system that can either switch between vertical and horizontal linear polarizations, or between right hand and left hand circular polarization. Which would be more useful? And is it worth the extra effort to build an antenna system that can switch between all four polarizations?
Also, I've been looking at the different ways of achieving circular polarization. I like the idea of using mechanical 1/4 wave separation between the two yagis so I don't have to cut phasing lines. Would it be possible to switch polarizations by putting a relay at the feedpoint of one of the yagis and switching which side of the driven element the center conductor and shield of the coax goes to? I've never seen this done before, but it seems to me it would work. Any thoughts?
Thanks and 73, Brady AC0XR
Brady,
I found a good discussion on this topic at:
https://forums.qrz.com/index.php?threads/vertical-or-angle-for-2m-70cm-circu...
And here's a link for a discussion on CP antennas:
http://www.qsl.net/sv1bsx/antenna-pol/polarization.html
BTW, I have linear antennas, 2M Horiz & 70 cm Vert, and experience deep fades. This requires me to time my calls to when I'm fairly sure I'll be able to hear responses.
GL/73, Bob K8BL
P.S. Don't Google RHCP unless you are a fan of the Red Hot Chili Peppers! :o)
________________________________ From: Brady Gordon ac0xr@lowswr.com To: amsat-bb@amsat.org Sent: Wednesday, April 12, 2017 5:17 PM Subject: [amsat-bb] Linear vs Circular Polarization
Hi Everyone,
I'm working on building a pair of crossed yagis for 2m and 70cm, and I have
some questions. I apologize if this has been discussed before, but I
couldn't find answers online so I was hoping you all could help me out.
First, it seems easiest to me to build an antenna system that can either
switch between vertical and horizontal linear polarizations, or between
right hand and left hand circular polarization. Which would be more
useful? And is it worth the extra effort to build an antenna system that
can switch between all four polarizations?
Also, I've been looking at the different ways of achieving circular
polarization. I like the idea of using mechanical 1/4 wave separation
between the two yagis so I don't have to cut phasing lines. Would it be
possible to switch polarizations by putting a relay at the feedpoint of one
of the yagis and switching which side of the driven element the center
conductor and shield of the coax goes to? I've never seen this done
before, but it seems to me it would work. Any thoughts?
Thanks and 73,
Brady AC0XR
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