X-GM-THRID: 1230276962607312874 X-Gmail-Labels: rsgb lf Delivered-To: daveyxm@gmail.com Received: by 10.115.73.3 with SMTP id a3cs1086881wal; Wed, 7 Mar 2007 08:05:44 -0800 (PST) Received: by 10.67.119.9 with SMTP id w9mr4631730ugm.1173283543593; Wed, 07 Mar 2007 08:05:43 -0800 (PST) Return-Path: Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mx.google.com with ESMTP id w40si1698290ugc.2007.03.07.08.05.40; Wed, 07 Mar 2007 08:05:43 -0800 (PST) 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) DomainKey-Status: bad (test mode) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1HOyYL-0001Ng-Gn for rs_out_1@blacksheep.org; Wed, 07 Mar 2007 15:59:45 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1HOyYI-0001NX-Si for rsgb_lf_group@blacksheep.org; Wed, 07 Mar 2007 15:59:42 +0000 Received: from smtp812.mail.ird.yahoo.com ([217.146.188.72]) by relay1.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1HOyYG-0007v8-Hz for rsgb_lf_group@blacksheep.org; Wed, 07 Mar 2007 15:59:42 +0000 Received: (qmail 75351 invoked from network); 7 Mar 2007 15:59:35 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=btinternet.com; h=Received:X-YMail-OSG:Message-ID:From:To:Subject:Date:MIME-Version:Content-Type:Content-Transfer-Encoding:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE; b=3aUVqQGaSpth/N6J2Fpn8qMMpCTwlZqUAH9KHwSs6WOMt2jPuovSuj2j4PCeTNf2FM6lmb8NcSZ2npq/L41qgnafVT+0ZSrRG/1C0gIFtKg9AbaxoqH+pZuRJKSlQjmy2DlbFlYrSZQVzI/ehl9j+FwvKPlVdAON/eEAajVGi1E= ; Received: from unknown (HELO lark) (alan.melia@btinternet.com@81.131.59.244 with login) by smtp812.mail.ird.yahoo.com with SMTP; 7 Mar 2007 15:59:34 -0000 X-YMail-OSG: .3aevnQVM1lnHXGmMnCXyN5mG3oJl5b5Du6K7AQruzJNNt5VPOGO9VKYsYje5tDjCi31pNyQPKA2fXTqDyyPAn7cap5hyd5IeBB8naYqUyiS6kZug.y4nhdZOXZdrxvu1vfbicqus.FA Message-ID: <002f01c760d1$a133b3e0$0300a8c0@lark> From: "Alan Melia" To: Date: Wed, 7 Mar 2007 15:56:10 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2615.200 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2615.200 DomainKey-Status: good (testing) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: LF: ERP spreadsheet ammended Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit 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: 2393 Hi all Jim has indicated that the formula I used to calcualte the radiation resistance is in error. I claim immunity for ridicule as the formula is quoted in page R-9 of the Admiralty Handbook vol 2 1938 !! :-)) However he also says that I have used the total radiated power rather than the more strictly defined ERP which relates to a mythical dipole. I aver that this is more meaningful for very short amateur LF aerials (and its in our favour !!) My stance is somewhat supported by the measurements made by Jim and Christer SM6PXJ several years ago on 136kHz where they found the measured fireld strength were about 6dB below those expected theoretically. Thus the aerial current calculation may yield a figure that is too high in "ERP" but the field strength generated is expected to be correct in practice. That is my defence, melud !! I am a "reasonable man". An ammended version has been posed to my web site Cheers de Alan G3NYK