Return-Path: Received: from rly-da05.mx.aol.com (rly-da05.mail.aol.com [172.19.129.79]) by air-da07.mail.aol.com (v121_r2.12) with ESMTP id MAILINDA074-a6a48bea03d15e; Wed, 03 Sep 2008 10:33:52 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-da05.mx.aol.com (v121_r2.11) with ESMTP id MAILRELAYINDA052-a6a48bea03d15e; Wed, 03 Sep 2008 10:33:38 -0400 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1KatQ1-0002ff-Uc for rs_out_1@blacksheep.org; Wed, 03 Sep 2008 15:33:13 +0100 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1KatQ1-0002fW-Fj for rsgb_lf_group@blacksheep.org; Wed, 03 Sep 2008 15:33:13 +0100 Received: from smtp2a.orange.fr ([80.12.242.140]) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1KatPy-0003c8-RW for rsgb_lf_group@blacksheep.org; Wed, 03 Sep 2008 15:33:13 +0100 Received: from me-wanadoo.net (localhost [127.0.0.1]) by mwinf2a22.orange.fr (SMTP Server) with ESMTP id 4D9D1700008E for ; Wed, 3 Sep 2008 16:33:01 +0200 (CEST) Received: from JR (Mix-Nancy-110-3-86.w193-248.abo.wanadoo.fr [193.248.196.86]) by mwinf2a22.orange.fr (SMTP Server) with ESMTP id DF8BB7000096 for ; Wed, 3 Sep 2008 16:32:59 +0200 (CEST) X-ME-UUID: 20080903143259915.DF8BB7000096@mwinf2a22.orange.fr Message-ID: <200809031633020046.00D00115@smtp.wanadoo.fr> In-Reply-To: <003001c906e2$a904a800$0900a8c0@AM> References: <200808251715030768.082E674C@smtp.wanadoo.fr> <003001c906e2$a904a800$0900a8c0@AM> X-Mailer: Courier 3.50.00.09.1098 (http://www.rosecitysoftware.com) (P) Date: Wed, 03 Sep 2008 16:33:02 +0200 From: "John RABSON" To: rsgb_lf_group@blacksheep.org Mime-Version: 1.0 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: Re: Sensing loop Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: quoted-printable 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-AOL-SCOLL-AUTHENTICATION: domain : post.thorcom.com ; SPF_helo = n X-AOL-SCOLL-AUTHENTICATION: domain : wanadoo.fr ; SPF_822_from = n Many thanks to all those who provided advice on this. I will pursue the mat= ter when the weather is better. At present it is raining and the static is=20= peaking 15 to 20 dB above DCF so I am not surprised that I can't identify an= y amateur signals. =20 John F5VLF *********** REPLY SEPARATOR *********** On 25/08/2008 at 19:40 Alan Melia wrote: >Hi John. It depends what you are trying to do ?? It sounds like you are >trying to calibrate the loop effective height. Jim, Christos, and Dick >Rollema have done some work on this Dick recommends a toroidal transformwe >slipper onto an outer wire. I believe this will induce an accuarately known >current in the main loop and so facilitate a calibration. I am not sure I >have the get available in the mail archive but you may find that Rink >Strobbe has archived it in his tech papers (or maybe aerials) sections. > >Best Wishes to You and Rosie >Alan G3NYK > > > >----- Original Message ----- >From: "John RABSON" >To: >Sent: Monday, August 25, 2008 4:15 PM >Subject: LF: Sensing loop > > >I have a 2 metre square 8 turn loop which is series resonant on 138kHz. To >calibrate this I am thinking of adding a single turn loop which can be fed >with a known current and therefore produce a known magnetic field. Should >this turn be within the main winding or should it be a much smaller loop at >the centre? > >John >F5VLF