Return-Path: Received: (qmail 29456 invoked from network); 13 May 2001 14:43:46 -0000 Received: from unknown (HELO warrior-inbound.servers.plus.net) (212.159.14.227) by excalibur.plus.net with SMTP; 13 May 2001 14:43:46 -0000 Received: (qmail 3540 invoked from network); 13 May 2001 14:43:12 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by warrior with SMTP; 13 May 2001 14:43:12 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.16 #2) id 14ywzM-0003Kn-00 for rsgb_lf_group-outgoing@blacksheep.org; Sun, 13 May 2001 15:36:52 +0100 Received: from smtp-1.visp.telinco.net ([212.1.130.1]) by post.thorcom.com with esmtp (Exim 3.16 #2) id 14ywzL-0003Ki-00 for rsgb_lf_group@blacksheep.org; Sun, 13 May 2001 15:36:51 +0100 Received: from [212.1.140.26] (helo=g4jnt) by smtp-1.visp.telinco.net with smtp (Exim 3.22 #1) id 14ywsL-0002Ch-00 for rsgb_lf_group@blacksheep.org; Sun, 13 May 2001 15:29:38 +0100 Message-ID: <001701c0dbb9$d035e6c0$1a8c01d4@g4jnt> From: "Andrew Talbot" To: rsgb_lf_group@blacksheep.org Subject: Re: LF: Measurement of antenna current Date: Sun, 13 May 2001 15:34:26 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 4.72.3110.1 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: You've made me think about it a lot more now. The AC/DC resistance argument is certainly valid. It does indeed mean that any capacitive field will be captured with less loss than letting it end up in lossy ground, or it would if the sheet covered the area captured by the E field due to the WHOLE antenna. However, just concentrating on the loading coil, which has a huge H field and very low E component is a different matter. What is the loss due to the H travelling through ground of poor conductivity ? - not too much I would estimate More thought required.............. Andy G4JNT >I thought it means that the current density over the thickness of the foil >is almost uniform with result that AC and DC resistance are almost equal. >But even with the thin foil that resistance will be so much smaller than the >resistance via the real earth that I expect almost all capacitive current >from the coil is captured by the foil. >Am I wrong? > >73, Dick, PA0SE > > > >