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Re: mounting crossed yagis



on 8/6/00 6:36 PM, James Farley at j.r.farley@ieee.org wrote:

> I have built a pair of homebrew Yagi's to get onto the sats.  I was
> planning to mount them in the "+" configuration (one beam horizontal, one
> beam vertical) but recently saw an installation where the guy had put them
> in an "X" configuration.
> 
> I was wondering if anyone has any thoughts on the advantages and
> disadvantages of each of these two configurations - the "+" would be easier
> for me to mount, but if the "X" is much better it could be worth doing a
> bit more engineering to get it to work.

As another poster has mentioned, if the antennas are truly circularly
polarized, then it should not matter.  However, if you use a metal mast
(likely),  a metal crossboom (possible, but not recommended), or you have
any other vertical or horizontal metal nearby, potential problems could
occur when mounting them in the + configuration.  Mounting in the X
configuration helps to ensure that you are decoupled from any other nearby
metal objects.

Some folks see a difference, others don't.  Mine are mounted in the X
position as I then have a shorter distance to clear my guy wires on my mast.
If one of your elements is the hypotenuse of a right triangle, then it's the
longest leg.  Make sense?

73,

Jon
NA9D

-------------------------------------
Jon Ogden
NA9D (ex: KE9NA)

Member:  ARRL, AMSAT, DXCC, NRA

http://www.qsl.net/ke9na

"A life lived in fear is a life half lived."

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