[ Reply | Next | Previous | Up ]
From: John Matz KB9II
Date: 18 Jun 1999
Time: 11:48:03
Remote Name: 129.188.33.200
Hi all I've been reading the forum notes/history and juat would like to mention a few things.
I work at Motorola Cellular Infrastructure, and we have been aware of the CTHA - Contrawound Toroidal Helix Antenna-for some time. Yes, it may radiate, but the sellers are really good at peddling snake oil. We decided not to touch it. ... waves penetrating mountains, etc.... magic!!
The GAP SuperC looks like a cross between a CFA and a short monopole. No magic claims here, just traditional radiation.
The CFA should work well. Yes, the size is not linked directly to frequency, but neither is a traditional monopole. One neat thing they have done is if radiation comes from E and H, then ANY way to generate H is OK. We don't have to put current through some lossy base-loading coil and put up with high losses. One can use a displacement current through a capacitor (D-plate) that is almost lossless. That really allows size shrinkage!
By the way, I'm building one for 2 m FM that's 2 inches tall. I figure comparisons would be easier to make to a quarter wave there.
TNX fer the BW.
John Matz KB9II - 160m thru light.