Return-Path: Received: (qmail 7574 invoked from network); 14 Jul 2001 08:22:14 -0000 Received: from unknown (HELO warrior-inbound.servers.plus.net) (212.159.14.227) by excalibur.plus.net with SMTP; 14 Jul 2001 08:22:14 -0000 Received: (qmail 3096 invoked from network); 14 Jul 2001 08:20:53 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by warrior with SMTP; 14 Jul 2001 08:20:53 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: from majordom by post.thorcom.com with local (Exim 3.16 #2) id 15LKSd-0003Lr-00 for rsgb_lf_group-outgoing@blacksheep.org; Sat, 14 Jul 2001 09:07:35 +0100 Received: from [204.202.140.199] (helo=webmailmta.go.com) by post.thorcom.com with esmtp (Exim 3.16 #2) id 15LKSZ-0003Lm-00 for rsgb_lf_group@blacksheep.org; Sat, 14 Jul 2001 09:07:32 +0100 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from gomailjtp01 ([10.212.0.161]) by mta07.seamail.go.com (Sun Internet Mail Server sims.4.0.2000.10.12.16.25.p8) with ESMTP id <0GGG0076KEDORJ@mta07.seamail.go.com> for rsgb_lf_group@blacksheep.org; Sat, 14 Jul 2001 01:03:24 -0700 (PDT) Date: Sat, 14 Jul 2001 01:03:26 -0700 (PDT) From: "John Sexton" Subject: LF: Re: 9kHz and the Induction field To: rsgb_lf_group@blacksheep.org Message-ID: <2615421.995097806209.JavaMail.computernetworks@gomailjtp01> MIME-Version: 1.0 X-Mailer: GoMail 3.0.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Hi All, When Andy queried the formulae yesterday, I later recalled the article in the first edition of the LF Experimenters Source Book, by Lloyd Butler, VK5BR, where he states: 1. The electric component of the induction field decreases with the cube of the distance and dB = 60log(d2/d1), where d2 and d1 are the relative distances. 2. The magnetic component of the induction field decreases with the square of the distance and dB = 40log(d2/d1). 3. Both the electric and magnetic components of the radiation field decrease directly with distance and dB = 20log(d2/d1). A graph is included in the article, showing the magnetic component of the induction field to be greater than the electric at distances of 0.1 of a wavelength. So for distances from about 3 to 5 kilometres the electric component of the induction field can be ignored but the magnetic component of the induction field is still significant. So it seems likely that a loop receive antenna should enable the unofficial record to be increased. 73, John, G4CNN email: computernetworks@go.com web page: http://www.g4cnn.f2s.com Question to Andy: Would it help or hinder your case if others were also to apply for an NOV for 9kHz? ___________________________________________________ GO.com Mail Get Your Free, Private E-mail at http://mail.go.com