Hi Jerry,
I'll make one more post on this fantasy....I mean topic.
> With all the discussion of the CFA, it might be worthwhile to consider it
> from the point of view of the reciprocity theorem. It is apparent that
> its capture area as a receiving antenna must be miniscule, so reciprocity
> says that as a transmitting antenna it should .........! In other words,
> don't waste your money or your time.
Capture area, or effective aperture, is often misapplied. Contrary to
popular ham-lore, capture area is totally independent of an
antenna's physical size. Capture area, or more correctly effective
aperture, relates only to antenna gain. You can find that clearly
defined in engineering textbooks, like Antennas by John Kraus.
But you are correct, the effective aperture of an antenna like the
CFA is very small. That's because it is impossible to make the
antenna efficient and/or directive enough to have gain.
There is one capture area effect of this antenna that amazes me.
I'm amazed so much attention is captured by a fantasy.
By the way, the CFA article author in Antenna X claimed....
1.) He invented the MFJ loop antenna. He had absolutely nothing to
do with it.
2.) He invented part of the MFJ analyzer. He had absolutely nothing
to do with it.
3.) He invented the small "magnetic" loop. Hertz used one in the
1800's, and it was described in detail in engineering text in the very
early 1900's.
Think about that.
73, Tom W8JI
w8ji@contesting.com
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