Return-Path: Received: (qmail 2171 invoked from network); 2 Aug 2001 15:36:53 -0000 Received: from unknown (HELO murphys-inbound.services.quay.plus.net) (212.159.14.225) by excalibur.plus.net with SMTP; 2 Aug 2001 15:36:53 -0000 Received: (qmail 1615 invoked from network); 2 Aug 2001 15:36:18 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys with SMTP; 2 Aug 2001 15:36:18 -0000 X-Priority: 3 Received: from majordom by post.thorcom.com with local (Exim 3.16 #2) id 15SKO1-0005ng-00 for rsgb_lf_group-outgoing@blacksheep.org; Thu, 02 Aug 2001 16:27:45 +0100 X-MSMail-Priority: Normal Received: from imo-r01.mx.aol.com ([152.163.225.97]) by post.thorcom.com with esmtp (Exim 3.16 #2) id 15SKO0-0005nP-00 for rsgb_lf_group@blacksheep.org; Thu, 02 Aug 2001 16:27:44 +0100 Received: from WarmSpgs@aol.com by imo-r01.mx.aol.com (mail_out_v31.9.) id l.e2.186fc5d4 (16790) for ; Thu, 2 Aug 2001 11:24:15 -0400 (EDT) X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 From: WarmSpgs@aol.com Message-ID: Date: Thu, 2 Aug 2001 11:24:15 EDT Subject: Re: LF: The CFA Antenna (again...) To: rsgb_lf_group@blacksheep.org MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 8bit X-Mailer: AOL 4.0 for Windows 95 sub 120 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: In a message dated 8/1/01 12:28:48 PM Eastern Daylight Time, j.r.moritz@herts.ac.uk 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