Return-Path: Received: (qmail 7706 invoked from network); 18 Aug 2001 09:38:14 -0000 Received: from unknown (HELO murphys-inbound.services.quay.plus.net) (212.159.14.225) by excalibur.plus.net with SMTP; 18 Aug 2001 09:38:14 -0000 Received: (qmail 25943 invoked from network); 18 Aug 2001 09:37:38 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys with SMTP; 18 Aug 2001 09:37:38 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.16 #2) id 15Y2U0-0005KQ-00 for rsgb_lf_group-outgoing@blacksheep.org; Sat, 18 Aug 2001 10:33:32 +0100 Received: from tvout.mail.uk.easynet.net ([194.6.96.5]) by post.thorcom.com with esmtp (Exim 3.16 #2) id 15Y2Tz-0005KL-00 for rsgb_lf_group@blacksheep.org; Sat, 18 Aug 2001 10:33:31 +0100 Received: from ericadodd (tnt-3-4.easynet.co.uk [195.40.202.4]) by tvout.mail.uk.easynet.net (Postfix) with SMTP id E4ADA62D53 for ; Sat, 18 Aug 2001 10:32:50 +0100 (BST) Message-ID: <000801c127ca$053ac820$04ca28c3@ericadodd> From: "g3ldo" To: rsgb_lf_group@blacksheep.org References: <005501c125c6$89d255e0$a684fc3e@ian> Subject: LF: Re: CFA Date: Sat, 18 Aug 2001 10:40:53 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4522.1200 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Hi Ian Your e-mail regarding the CFA antenna got through the reflector OK. > Maybe a bit "old hat" - no pun intended - but I see GM3HAT has a bit on the > CFA in the July issue of RSARS mag, "Mercury".( Actually while I was > presidenting he sent me a copy of the paper presented at the IEE conference > in 1997. I can't follow either of them.) As regards the CFA papers I don't think you are intended to follow them.What we have with these papers is obfuscation rather than clarification and mathematics rather than simple testable models. Any antenna design, which invokes Maxwell's equations as support, without a considerable amount of comparative test measurements with known antennas, is suspect. While theoretical analysis is fine you must build and test the model - in other words experiment. Every CFA test that I have ever heard of has either been followed by silence or an unfavourable result. The only detailed test I have seen documented is described in 'CFA - RIP?', Electronics World + Wireless World, May 1993. (e-mail me for a copy if you want one). If anyone has other well documented comparative test results of the CFA I should be pleased to see them. Considering how long the CFA antenna has been around you would expect, considering the amateur radio need for compact antennas, that this antenna would be real success story. It has not. Regards, Peter, G3LDO e-mail Web