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Re: LF: The CFA Antenna (again...)

To: [email protected]
Subject: Re: LF: The CFA Antenna (again...)
From: [email protected]
Date: Thu, 2 Aug 2001 11:24:15 EDT
Reply-to: [email protected]
Sender: <[email protected]>
In a message dated 8/1/01 12:28:48 PM Eastern Daylight Time, [email protected] writes:
<< Hmmmmm - very interesting - I can't wait to see the legal battle over
patent infringements! >>
You mean, of course, in jurisdictions where neither device has to be
demonstrated to actually work before infringement can exist? :-)
The timing of this thread is interesting. I've been following the EH antenna
since last September, when its co-developers presented a highly promotional
paper at the IEEE Broadcast Technology Symposium in Washington. One of them,
Bob Zimmerman, became disillusioned with the antenna and left the company
last winter or early in the spring. I live only a little more than an hour's
drive from the test site, and have been waiting for them to obtain FCC
experimental authorization, which does not appear to be forthcoming.
For the record, the W5QJR site is by Ted Hart, the other developer. His site
shows the biconical version, but it can also be configured as a plain
inverted cone over groundplane. His contention is that for a "magic" conical
angle and a length that is a particular fraction of a wavelength, resonating
the electrically-short antenna with a single suitable inductor results in a
50-ohm resistive load presented to the transmitter and synthesis of the
Poynting vector in space, etc.
But as to why the timing is notable: In the same batch of e-mail as these
messages from the reflector, I received word of a new online edition of an
antenna experimenter's publication, antenneX, in which it appears the CFA is
falling on its face--or, on its top-hatted cylinder, if you prefer--among us
pesky commercial users, who have the unrealistic notion that anything we
spend hundreds of kilodollars on ought to actually work.
Check: http://www.antennex.com/Stones/ for the publisher's latest editorial.
The whole matter is turning into a big disappointment for him, as the
magazine has been promoting CFAs for amateur use for quite some time.
73,
John


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