Return-Path: Received: from mtain-mj01.r1000.mx.aol.com (mtain-mj01.r1000.mail.aol.com [172.21.164.85]) by air-df08.mail.aol.com (v129.4) with ESMTP id MAILINDF082-5eff4bd84b1f39e; Wed, 28 Apr 2010 10:50:07 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-mj01.r1000.mx.aol.com (Internet Inbound) with ESMTP id BBB7A380000D4; Wed, 28 Apr 2010 10:50:03 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1O78ZU-0003kb-Mc for rs_out_1@blacksheep.org; Wed, 28 Apr 2010 15:49:04 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1O78ZU-0003kS-A9 for rsgb_lf_group@blacksheep.org; Wed, 28 Apr 2010 15:49:04 +0100 Received: from smtp824.mail.ird.yahoo.com ([217.146.188.234]) by relay1.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1O78ZS-0002dI-6o for rsgb_lf_group@blacksheep.org; Wed, 28 Apr 2010 15:49:04 +0100 Received: (qmail 30236 invoked from network); 28 Apr 2010 14:48:56 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=btinternet.com; h=DKIM-Signature:Received:X-Yahoo-SMTP:X-YMail-OSG:X-Yahoo-Newman-Property:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:Content-Transfer-Encoding:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE:X-Antivirus:X-Antivirus-Status; b=q8gH8moEwjUBT477w/A8+nvWbDfZO6cJplhCiPyQnQNSfUWDgb0osKuXI/91UeGhX5keY0SPOUBZY8TlfhXF8lfO4r1PsbDstUPI+Hryt8GMmsWQDeJ+9PWeMKqLwyfJNMsEbhbhz1NkURohIVI2QEXfxKCJGbocUxqwhbF1L98= ; DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=btinternet.com; s=s1024; t=1272466136; bh=HXxJ/LSbTGpE89X5QTzZE3IOy2R+fvB1AMv2zXsi6HI=; h=Received:X-Yahoo-SMTP:X-YMail-OSG:X-Yahoo-Newman-Property:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:Content-Transfer-Encoding:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE:X-Antivirus:X-Antivirus-Status; b=nOaEP2R4mFDP6jGh5345L4r6BvmjG+4WrdBnDxcDFfzV9jaGDeh9jGy/neWlhgVFxfdOH5IBaQ1MFPax7VKa9qbRMBUUzwWLVBubNLYNfEK4UY+nbXKke4TanJ6H2fBUDE4AWl4KK8tQkeUNBTtpPBEKKECwSSryJ1T2KTZCTw0= Received: from lark (alan.melia@81.153.0.246 with login) by smtp824.mail.ird.yahoo.com with SMTP; 28 Apr 2010 07:48:56 -0700 PDT X-Yahoo-SMTP: fpz.2VeswBBs59bVshRPmMN51lcO2lgFRIvE4XTqE8dRwOxd70E- X-YMail-OSG: apvsUF4VM1n6L_eYAATPYMDTyOzFhhZJ2i88c2XcUsnsYBP_1myk1aoe_tSr.n8azgFyzzx6Rg8BmTd0pDPUy6zcUCxCFxfY.20_mvOmKm0hzDl.faTYyV3AMG2o5L3iRY4tHsoK1d45JkLXJPwFqU8qEfiYCzzo46sI7Dx02IepT6Qx36mhNtXWDwR9O1FfqFQnR7juz0QHL6N325TTXlz5Ld7aaB5ALrAfR4vquT_ymCa.tPhZB5aHTLXVnEtFOlV.lRWOZI.ea_7pN9HbPTz0aZe9r1YVaOaI_lg- X-Yahoo-Newman-Property: ymail-3 Message-ID: <005b01cae6e1$ea912010$4001a8c0@lark> From: "Alan Melia" To: References: Date: Wed, 28 Apr 2010 15:48:47 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1983 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1983 X-Antivirus: avast! (VPS 100428-0, 28/04/2010), Outbound message X-Antivirus-Status: Clean DomainKey-Status: good (testing) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,UNPARSEABLE_RELAY=0.001 Subject: LF: Re: Antenna Article 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 x-aol-global-disposition: G X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d273.1 ; domain : btinternet.com DKIM : fail x-aol-sid: 3039400c89a24bd84b1b64c8 X-AOL-IP: 193.82.116.20 Hi JB there is something similar to this I believe in Rick's ON7YD's web tutorial on LF antennas. http://www.strobbe.eu/on7yd/136ant/ look at section 2.12 Is this a case of feeding at an elevated tapping point to get a better impedance.....very short antennas are very low in impedance at 160........you may find this doesnt work at LF (136 - 180) due to the much higher ground losses.....interesting experiment though. Alan G3NYK ----- Original Message ----- From: "John Bruce McCreath" To: "& UK) and MedFer bands Discussion of the Lowfer (US European" Cc: Sent: Wednesday, April 28, 2010 1:35 PM Subject: LF: Antenna Article Hello LFers & Lowfers, Volume 7 of the ARRL Antenna Compendium has an interesting article by John, VE2CV, on an electrically small antenna for 160 meters. He mentions how a virtual inductance can be created at the top of a tower by means of "insulating a suitable conductor inside the tower and shorting it to the tower at some judicious length away from the end." The top loading wires are attached to the top of this conductor which extends above the top of the tower by some distance. Has anyone here tried this very interesting approach? I don't recall hearing or reading of this method of putting an inductor at the top of a vertical section of a top loaded LF antenna. Being more of a mechanical nature rather than the usual elevated coil, its losses may be less. I might give it a try myself just to check it out. 73, J.B., VE3EAR LowFER Beacon "EAR" 188.830 kHz. QRSS30