Return-Path: Received: (qmail 19859 invoked from network); 11 Mar 2002 08:54:02 -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; 11 Mar 2002 08:54:02 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: (qmail 20903 invoked from network); 11 Mar 2002 08:54:00 -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; 11 Mar 2002 08:54:00 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 16kMsR-0001os-00 for rsgb_lf_group-outgoing@blacksheep.org; Mon, 11 Mar 2002 10:17:59 +0000 Received: from mail2.cc.kuleuven.ac.be ([134.58.10.50]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 16kMsQ-0001on-00 for rsgb_lf_group@blacksheep.org; Mon, 11 Mar 2002 10:17:58 +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 g2B8dOvY121160 for ; Mon, 11 Mar 2002 09:39:25 +0100 Message-ID: <3.0.1.16.20020311093458.2d17e36a@pb623250.kuleuven.be> X-Sender: pb623250@pb623250.kuleuven.be X-Mailer: Windows Eudora Pro Version 3.0.1 (16) Date: Mon, 11 Mar 2002 09:34:58 To: rsgb_lf_group@blacksheep.org From: "Rik Strobbe" Subject: RE: LF: RE: Re: loops In-reply-to: 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 Bill, >>So based on that a 10m high and 100m long loop should perform as well 32m >>high square loop. Doubling the length of a long&low loop should increase >>the radiation resistance by 4 and the loss resistance by 2, resulting in an >>overal gain of 2 (= 3dB). Does the above fit with your math ? > >I'm with you except that a gain of 2 would translate to a 6db increase. Quadrupling the radiation resistance will give a 6dB gain. But at the same time the loss resistance is also doubled, what will inflict a 3dB loss. So overall gain is 'only' 3dB. Eg : Assume you gave a loop with a radiation resistance of 1 milli-Ohm and a loss of 5 Ohm. Putting 400 W into this loop will result in 8.94 A loop current, the radiated power will be 80 mW (ignoring loop gain for simplicity). Doublong the loop length will increase the radiation resistance to 4 milli-Ohm and the loss resistance to 10 Ohm. With 400 W th loop current will now be 6.32 A and the radiated power will be 160mW. This is a 3dB increase. The above assumes (simplifies) that the only losses will be 'copper loss'. 73, Rik ON7YD