Return-Path: Received: (qmail 95498 invoked from network); 21 Jan 2005 06:47:00 -0000 Received: from unknown (HELO ptb-spamcore01.plus.net) (192.168.71.1) by ptb-mailstore01.plus.net with SMTP; 21 Jan 2005 06:47:00 -0000 Received: from mailnull by ptb-spamcore01.plus.net with spamcore-l-b (Exim 4.32; FreeBSD) id 1CrsXs-000KWd-A6 for dave@picks.force9.co.uk; Fri, 21 Jan 2005 06:45:27 +0000 Received: from [192.168.67.1] (helo=ptb-mxcore01.plus.net) by ptb-spamcore01.plus.net with esmtp (Exim 4.32; FreeBSD) id 1CrsXr-000KWT-WD for dave@picks.force9.co.uk; Fri, 21 Jan 2005 06:45:24 +0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore01.plus.net with esmtp (Exim) id 1CrsZY-0007bD-Iu for dave@picks.force9.co.uk; Fri, 21 Jan 2005 06:47:09 +0000 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1CrsVR-00049D-T0 for rs_out_1@blacksheep.org; Fri, 21 Jan 2005 06:42:53 +0000 Received: from [193.82.116.30] (helo=relay.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1CrsVR-000494-Gq for rsgb_lf_group@blacksheep.org; Fri, 21 Jan 2005 06:42:53 +0000 Received: from relay.sotline.ru ([80.89.139.226]) by relay.thorcom.net with esmtp (Exim 4.43) id 1CrsVO-0007ds-N1 for rsgb_lf_group@blacksheep.org; Fri, 21 Jan 2005 06:42:53 +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 j0L6gO1B070585 for ; Fri, 21 Jan 2005 12:42:24 +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 j0L6gKIG025140 for ; Fri, 21 Jan 2005 12:42:21 +0600 (OS) Received: from localhost (fitec@localhost) by noname.nodomain.nowhere (8.8.5/8.8.5) with SMTP id MAA00243 for ; Fri, 21 Jan 2005 12:59:44 GMT X-Authentication-Warning: noname.nodomain.nowhere: fitec owned process doing -bs Date: Fri, 21 Jan 2005 12:59:44 +0000 (GMT) From: "Alexander S. Yurkov" To: rsgb_lf_group@blacksheep.org In-Reply-To: <005c01c4ff30$ea189850$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: Coil Winding2, de VY1JA 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 Thu, 20 Jan 2005, J. Allen wrote: > Alex's calculation of my antenna system indicates that a base loading coil > of 700 Ohms is needed. > > I was thinking of reducing the solenoid loss by paralleling two or more #17 > wires and close-winding them. If I parallel wind three #17 wires will it be > worth the effort in reducing coil loss or does a simple coil with only one > #17 conductor make any sense here? If You paralleling two or more wires then coil loss will NOT decrease too much. Moreover in some case loss can increase not decrease. It depend on coil shape (D/l ratio). It is not too dificult to understand. If You use two or more wires then coil length increase. This yeld more turns to achive inductance needed. More turns - more wire length - more loss in one wire. But certanly two wires in parallel have less resistance. Then Q-factor will be APROXIMATLY the same. Use two or more wires in parallel is resonable to optimaze former_diameter/winding_length ratio of a solenoid ONLY. Winding with space equal to wire diameter yelds Q-factor beter. But not too much. Dependence is not strong. Thus You can wind Your coil close. Moreover Q-factor depend ONLY on wire-diameter/winding-space ratio, coil-diameter/winding-length ratio, former diameter and DO NOT depend on wire diameter itself (if wire radius is more then pentation depth). This conclusion looks very strange of cose. I was very suprised when I derive such a conclusion theoreticaly few years ago. But few experiments with some coils ensure me this is true:-) This strange behaviour of Q-factor is a result of proximity effect. What is diameter of wire #17 in millimeters? I'll do aproximate estimation coil with Your formers. Though wire is coper... 73 de RA9MB/Alex http://www.qsl.net/ra9mb