Return-Path: Received: (qmail 21251 invoked from network); 9 Jan 2005 05:54:05 -0000 Received: from unknown (HELO ptb-spamcore01.plus.net) (192.168.71.1) by ptb-mailstore02.plus.net with SMTP; 9 Jan 2005 05:54:05 -0000 Received: from mailnull by ptb-spamcore01.plus.net with spamcore-l-b (Exim 4.32; FreeBSD) id 1CnW1D-000KB2-LV for dave@picks.force9.co.uk; Sun, 09 Jan 2005 05:53:40 +0000 Received: from [192.168.67.2] (helo=ptb-mxcore02.plus.net) by ptb-spamcore01.plus.net with esmtp (Exim 4.32; FreeBSD) id 1CnW1D-000KAz-Io for dave@picks.force9.co.uk; Sun, 09 Jan 2005 05:53:39 +0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore02.plus.net with esmtp (Exim) id 1CnW1c-000ALd-Jc for dave@picks.force9.co.uk; Sun, 09 Jan 2005 05:54:04 +0000 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1CnW0o-0002lu-Rd for rs_out_1@blacksheep.org; Sun, 09 Jan 2005 05:53:14 +0000 Received: from [193.82.116.30] (helo=relay.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1CnW0o-0002ll-8U for rsgb_lf_group@blacksheep.org; Sun, 09 Jan 2005 05:53:14 +0000 Received: from relay.sotline.ru ([80.89.139.226]) by relay.thorcom.net with esmtp (Exim 4.43) id 1CnW0l-00085x-KE for rsgb_lf_group@blacksheep.org; Sun, 09 Jan 2005 05:53:14 +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 j095r95n040308 for ; Sun, 9 Jan 2005 11:53:09 +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 j095r76k026711 for ; Sun, 9 Jan 2005 11:53:08 +0600 (OS) Received: from localhost (fitec@localhost) by noname.nodomain.nowhere (8.8.5/8.8.5) with SMTP id MAA00272 for ; Sun, 9 Jan 2005 12:09:11 GMT X-Authentication-Warning: noname.nodomain.nowhere: fitec owned process doing -bs Date: Sun, 9 Jan 2005 12:09:10 +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: 0.1 (/) X-Spam-Report: autolearn=failed,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-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-Spam-Filtered: by PlusNet SpamCORE (v3.00) Content-transfer-encoding: 8bit On Fri, 7 Jan 2005, J. Allen wrote: > tuner loss, the antenna impedance with the resistance of wire and loss > resistance, the antenna connection impedance estimates at 7.6 Ohms. 7.6 Ohm of coil resistence is reasonable. But it can be decreased if increase a diameter of a coil. Very aproximative coil Q-factor is about coil diameter in milimeters if step of wireing is optimal (step is twice of wire diameter). This is for solid wire, not for litz. More exactly Q-factor can be estimated also. But usialy coil loss is not the main loss if Q-factor is large! Main loss is a ground and enviroment loss! If conterpoise is elevated then ground loss can be estimated by NEC-2. If it is burred then one need NEC-4. Or one can use very aproximative formulas derived by me (look to archive of this list). Unfortunely all of this is true only if an antenna is out of trees, buildings e.t.c. Othervice this enviroment yelds losses wich are much grater then ground loss itself :-( I do not know how to estimate enviroment losses theoreticaly :-( May be by elnec modeling of trees? But it is a hard work! It is not simple to estimate real LF antenna effectivity theoreticaly! 73 de RA9MB/Alex http://www.qsl.net/ra9mb