Hi Pete,
Take a look at this article on helix ground planes: http://www.alzacomm.com/downloads/Helix_Letter.pdfhttp://www.alzacomm.com/downloads/Helix_Letter.pdf
It is also possible to make a helix with no ground plane. This was a cover article of the IEEE Antennas magazine in 1995. Search for the article
Kraus, J.D. A helical-beam antenna without a ground plane. IEEE Ant. Prop. Mag., 37 (2), 45, 1995.
at
http://ieeexplore.ieee.org/Xplore/guesthome.jsphttp://ieeexplore.ieee.org/Xplore/guesthome.jsp
You have to buy this one from IEEE if you are not an APS member.
Best of luck with your projects!
73, Tony AA2TX ---
At 08:51 PM 6/3/2010, Pete Norris, K1HZU wrote:
Hi All: I am rebuilding a 440 MHZ Helix that I built several years ago . It worked very well, but I would like to reduce the size of the reflector to a more manageable size than I had before. The only reference to reflector size I can find is, "minimum 20" ". I may be looking in the wrong places. I would appreciate it, if someone would steer me in the right direction. Thanks, Pete, K1HZU
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