Return-Path: <owner-rsgb_lf_group@blacksheep.org> Received: from rly-df08.mx.aol.com (rly-df08.mail.aol.com [172.19.156.21]) by air-df06.mail.aol.com (v124.15) with ESMTP id MAILINDF063-56e4a6873ff14f; Thu, 23 Jul 2009 10:30:40 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-df08.mx.aol.com (v124.15) with ESMTP id MAILRELAYINDF085-56e4a6873ff14f; Thu, 23 Jul 2009 10:30:24 -0400 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1MTzHm-0004gy-Rr for rs_out_1@blacksheep.org; Thu, 23 Jul 2009 15:28:42 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1MTzHm-0004gp-7E for rsgb_lf_group@blacksheep.org; Thu, 23 Jul 2009 15:28:42 +0100 Received: from cmsout01.mbox.net ([165.212.64.31]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from <dibene@usa.net>) id 1MTzHR-0001qQ-EY for rsgb_lf_group@blacksheep.org; Thu, 23 Jul 2009 15:28:24 +0100 Received: from cmsout01.mbox.net (cmsout01-lo [127.0.0.1]) by cmsout01.mbox.net (Postfix) with ESMTP id E4E852ACD18 for <rsgb_lf_group@blacksheep.org>; Thu, 23 Jul 2009 14:28:29 +0000 (GMT) Received: from cmsapps04.cms.usa.net [165.212.11.133] by cmsout01.mbox.net via smtad (C8.MAIN.3.53L) with ESMTP id XID470NgwoCE9709X01; Thu, 23 Jul 2009 14:28:30 -0000 X-USANET-Source: 165.212.11.133 IN dibene@usa.net cmsapps04.cms.usa.net X-USANET-MsgId: XID470NgwoCE9709X01 Received: from [127.0.0.1] [151.47.218.242] by cmsapps04.cms.usa.net (ESMTPA/dibene@usa.net) via mtad (C8.MAIN.3.53P) with ESMTPA id 905NgwoCb2064M40; Thu, 23 Jul 2009 14:28:27 -0000 X-USANET-Auth: 151.47.218.242 AUTH dibene@usa.net [127.0.0.1] Message-ID: <4A687388.4050801@usa.net> Date: Thu, 23 Jul 2009 16:28:24 +0200 From: Alberto di Bene <dibene@usa.net> User-Agent: Thunderbird 2.0.0.22 (Windows/20090605) MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <1MTixd-0cGXyK0@fwd00.t-online.de> In-Reply-To: <1MTixd-0cGXyK0@fwd00.t-online.de> X-Enigmail-Version: 0.96.0 X-Antivirus: avast! (VPS 090722-0, 07/22/2009), Outbound message X-Antivirus-Status: Clean Z-USANET-MsgId: XID905NgwoCC2064X40 X-Karma: unknown: X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: Loop discussion Content-Type: text/plain; charset=ISO-8859-1; format=flowed 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-IP: 193.82.116.20 X-Mailer: Unknown (No Version) James and Ha-Jo, thanks for your answers and considerations about using the loop itself as the primary of the transformer. I thought that it could be a good idea, based on this consideration : If I make a single turn loop using copper tubing, it will have a very low resistance, guesstimated between one thousandth and one hundredth of a ohm. A regular primary winding on a transformer will have a resistance at least an order of magnitude greater. IMHO, this affect negatively the Q of the loop... if I use the loop as primary, closing the single turn on itself with a good soldering, the Q would be unaffected, also because the secondary is not loaded... In fact, my intention was to have a high number of turns on the secondary, let's say at least 20, directly connected to the gate of a FET used as a source follower. This, again IMHO, would have the benefit to leave the Q of the loop at its unloaded value, and to have a great voltage gain, given by the high turn ratio of the transformer... Naturally, this will imply that the loop cannot be tuned, but there are applications for untuned loops. Is this line of thinking completely wrong ? Thanks for any considerations. 73 Alberto I2PHD