Return-Path: Received: (qmail 24902 invoked from network); 8 Jan 2005 19:24:11 -0000 Received: from unknown (HELO ptb-spamcore02.plus.net) (192.168.71.3) by ptb-mailstore01.plus.net with SMTP; 8 Jan 2005 19:24:11 -0000 Received: from mailnull by ptb-spamcore02.plus.net with spamcore-l-b (Exim 4.32; FreeBSD) id 1CnMBK-0000ub-4E for dave@picks.force9.co.uk; Sat, 08 Jan 2005 19:23:27 +0000 Received: from [192.168.67.2] (helo=ptb-mxcore02.plus.net) by ptb-spamcore02.plus.net with esmtp (Exim 4.32; FreeBSD) id 1CnMBK-0000uY-1V for dave@picks.force9.co.uk; Sat, 08 Jan 2005 19:23:26 +0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore02.plus.net with esmtp (Exim) id 1CnMC1-0005sm-Od for dave@picks.force9.co.uk; Sat, 08 Jan 2005 19:24:09 +0000 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1CnM91-0008Ji-92 for rs_out_1@blacksheep.org; Sat, 08 Jan 2005 19:21:03 +0000 Received: from [193.82.116.30] (helo=relay.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1CnM90-0008JZ-US for rsgb_lf_group@blacksheep.org; Sat, 08 Jan 2005 19:21:02 +0000 Received: from relay.sotline.ru ([80.89.139.226]) by relay.thorcom.net with esmtp (Exim 4.43) id 1CnM8v-0000h2-9E for rsgb_lf_group@blacksheep.org; Sat, 08 Jan 2005 19:21:02 +0000 Received: from astral.omskcity.com (mxs.sotline.ru [80.89.139.227]) by relay.sotline.ru (8.12.8p2/8.12.8) with ESMTP id j08JKq5n099731 for ; Sun, 9 Jan 2005 01:20:52 +0600 (OMST) (envelope-from fitec@omskcity.com) Received: from noname.nodomain.nowhere (host196.m02.dial.sotline.ru [81.176.51.196]) by astral.omskcity.com (8.x.x) with ESMTP id j08JKmwJ000763 for ; Sun, 9 Jan 2005 01:20:49 +0600 (OS) Received: from localhost (fitec@localhost) by noname.nodomain.nowhere (8.8.5/8.8.5) with SMTP id BAA00263 for ; Sun, 9 Jan 2005 01:39:23 GMT X-Authentication-Warning: noname.nodomain.nowhere: fitec owned process doing -bs Date: Sun, 9 Jan 2005 01:39:23 +0000 (GMT) From: "Alexander S. Yurkov" To: rsgb_lf_group@blacksheep.org In-Reply-To: <008201c4f48b$725f0d80$6401a8c0@eagles> Message-ID: MIME-Version: 1.0 X-SPF-Result: relay.thorcom.net: domain of omskcity.com designates 80.89.139.226 as permitted sender X-Spam-Score: 1.3 (+) X-Spam-Report: autolearn=no,DATE_IN_FUTURE_06_12=1.202,FORGED_RCVD_HELO=0.05 Subject: Re: LF: Antenna plans de J. 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=1.9 required=5.0 tests=DATE_IN_FUTURE_06_12 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-Spam-Filtered: by PlusNet SpamCORE (v3.00) Content-transfer-encoding: 8bit Dear J, On Fri, 7 Jan 2005, J. Allen wrote: > > Elnec shows the radiation resistance of the antenna with all resistances set > to zero, to be about 0.02053 Ohms. It seems to be very strange. Simple formula for top loaded vertical R=1600(H/lambda)^2 yelds about 0.16 Ohms if H=20m. Though it is more resonable then 0.02 Ohms. Are You sure there is no mistake in elnec modeling? Number of computer experiments with NEC done by me for different antennas on 136 kHz yelds results very close to this simple formula. 73 de RA9MB/Alex http://www.qsl.net/ra9mb