X-GM-THRID: 1236142525855550516 X-Gmail-Labels: rsgb lf Delivered-To: daveyxm@gmail.com Received: by 10.78.172.1 with SMTP id u1cs307672hue; Fri, 11 May 2007 02:56:18 -0700 (PDT) Received: by 10.67.10.18 with SMTP id n18mr2732860ugi.1178877378459; Fri, 11 May 2007 02:56:18 -0700 (PDT) Return-Path: Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mx.google.com with ESMTP id u1si6244730uge.2007.05.11.02.56.16; Fri, 11 May 2007 02:56:18 -0700 (PDT) Received-SPF: neutral (google.com: 193.82.116.20 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1HmRlY-0004UR-VQ for rs_out_1@blacksheep.org; Fri, 11 May 2007 10:50:24 +0100 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1HmRlY-0004UI-Hy for rsgb_lf_group@blacksheep.org; Fri, 11 May 2007 10:50:24 +0100 Received: from rusty.kulnet.kuleuven.ac.be ([134.58.240.42]) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1HmRlX-0006Gf-Pi for rsgb_lf_group@blacksheep.org; Fri, 11 May 2007 10:50:24 +0100 Received: from localhost (localhost [127.0.0.1]) by rusty.kulnet.kuleuven.ac.be (Postfix) with ESMTP id 776A31D78F0 for ; Fri, 11 May 2007 11:50:18 +0200 (CEST) Received: from smtps01 (octavianus.kulnet.kuleuven.ac.be [134.58.240.71]) by rusty.kulnet.kuleuven.ac.be (Postfix) with ESMTP id 212411D7884 for ; Fri, 11 May 2007 11:50:17 +0200 (CEST) Received: from smtps01 (localhost [127.0.0.1]) by smtps01 (Postfix) with ESMTP id A62872E68FC; Fri, 11 May 2007 11:50:15 +0200 (CEST) Received: from dell-rik.fys.kuleuven.be (pc-10-33-165-177.fys.kuleuven.ac.be [10.33.165.177]) by smtps01 (Postfix) with ESMTP id 6B25E2E68F3 for ; Fri, 11 May 2007 11:50:15 +0200 (CEST) X-Mailer: QUALCOMM Windows Eudora Version 7.1.0.9 Date: Fri, 11 May 2007 11:52:24 +0200 To: rsgb_lf_group@blacksheep.org From: Rik Strobbe In-Reply-To: <20070511090338.CDF26559A@mta-fe.casema.nl> References: <001e01c7933b$4ae4a340$fe79a8c0@PCVONWALTER> <20070511090338.CDF26559A@mta-fe.casema.nl> Mime-Version: 1.0 Message-Id: <20070511095015.6B25E2E68F3@smtps01> X-Virus-Scanned: by KULeuven Antivirus Cluster X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: LF: 500 kHz loop antenna ? Content-Type: text/plain; charset="us-ascii"; format=flowed X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=none autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false Status: O X-Status: X-Keywords: X-UID: 2746 Dear all, did anyone try a loop antenna (for transmitting) on 500 kHz ? As the radiation resistance of a small loop increases with the 4th power of the frequency a loop should be about 22 dB more efficient on 500 kHz compared to 136 kHz. A rather modest 100 m^2 loop should have a radiation resistance of about 0.0024 Ohm and thus require only 6.5 A antennacurrent to get 0.1 W ERP. For a vertical the gain is "only" about 11 dB (plus whatever is gained from lower losses). 73, Rik ON7YD Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm