Return-Path: Received: (qmail 16552 invoked from network); 18 Mar 2002 09:39:27 -0000 Content-Transfer-Encoding: 8bit Received: from unknown (HELO murphys-inbound.services.quay.plus.net) (212.159.14.225) by excalibur.plus.net with SMTP; 18 Mar 2002 09:39:27 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: (qmail 27452 invoked from network); 18 Mar 2002 09:39:25 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys.services.quay.plus.net with SMTP; 18 Mar 2002 09:39:25 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 16muyT-000603-00 for rsgb_lf_group-outgoing@blacksheep.org; Mon, 18 Mar 2002 11:06:45 +0000 Received: from mail2.cc.kuleuven.ac.be ([134.58.10.50]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 16muyL-0005zw-00 for rsgb_lf_group@blacksheep.org; Mon, 18 Mar 2002 11:06:43 +0000 Received: from LCBD15.fys.kuleuven.ac.be (LCBD15.fys.kuleuven.ac.be [134.58.80.15]) by mail2.cc.kuleuven.ac.be (8.12.1/8.12.1) with SMTP id g2I9RUuN028680 for ; Mon, 18 Mar 2002 10:27:31 +0100 Message-ID: <3.0.1.16.20020318102251.095f5cda@pb623250.kuleuven.be> X-Sender: pb623250@pb623250.kuleuven.be X-Mailer: Windows Eudora Pro Version 3.0.1 (16) Date: Mon, 18 Mar 2002 10:22:51 To: rsgb_lf_group@blacksheep.org From: "Rik Strobbe" Subject: Re: LF: Loop and inverted L aerials In-reply-to: <000101c1cc74$fa9620e0$9721073e@default> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Hello Alan, >Using Dave G3YMCs figures for dynamic resistance and and assuming it increases >linearly with increasing loop periphery, I worked out the efficency of several >loop sizes. Assuming that dynamic resistance = radiation resistance and periphery = circumreference : The radiation resistance of a loop is proportional to the square of the loop area. So doubling the circumreference (keeping the shape unchanged) will quadruple the loop area and thus it will increase the radiation resistance by a factor of 16. But at the same time it will double the 'copper-loss' so the efficiency of the loop will increase 8 times (assuming the 'copper-loss' is dominant). 73, Rik ON7YD