I was under the impression that it didn't matter how that antenna was oriented (it circular) and that a conductive mast shouldn't be used.

From the manual for the M2 circular polarized 70cm yagi:

“The 436CP30 is a circular polarized antenna and creates a field in all planes or polarities. Performance DETERIORATES SIGNIFICANTLY if it is mounted on a metal (conductive) mast or cross boom. A mast or cross boom of any NON-CONDUCTIVE material must be used. Fiberglass is the prime choice for its strength and weather resistance. Mount the 436CP30 so that element tips are at least 12” from any conductive material (mast, tower, feed line, etc.).”

Cal - N7AY


On 9/10/2023 4:39 PM, Gary via AMSAT-BB wrote:

It will allow you to use a conductive crossboom, and/or route your feedline back out of the antennas along the crossboom. Antenna guru Kent Britain, wa5vjb studied and tested this. He wrote a paper on it and published it as part of an AMSAT symposium. You can see the paper here:

Using Metal Cross Booms w/ Satellite Antennas (kk0sd.net)

 

73,

Joe kk0sd

 

From: K4IDC via AMSAT-BB <amsat-bb@amsat.org>
Sent: Sunday, September 10, 2023 4:54 PM
To: AMSAT-BB <amsat-bb@amsat.org>
Subject: [AMSAT-BB] Cross Polarized Yagi: X or +

 

I'm new to this mode..

I was advised by someone I think is knowledgeable, and certainly more so than me, to orient my cross polarized 2m Yagi so that the elements resemble an X rather than a +. Easily enough done...what's the advantage? 

It's my understanding that the two sets of elements are out of phase by 90° & combined at the common feed point to emulate circular polarization. How does the rotation along the boom axis make a difference?

Seeking understanding...

 

Thanks,

Robin Midgett K4IDC


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