Return-Path: Received: from mtain-di06.r1000.mx.aol.com (mtain-di06.r1000.mx.aol.com [172.29.64.10]) by air-da09.mail.aol.com (v127_r1.1) with ESMTP id MAILINDA093-86414b94a04111d; Mon, 08 Mar 2010 01:59:13 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-di06.r1000.mx.aol.com (Internet Inbound) with ESMTP id 7D9FB3800008D; Mon, 8 Mar 2010 01:59:11 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NoWtx-0007zr-Rm for rs_out_1@blacksheep.org; Mon, 08 Mar 2010 06:57:17 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NoWtx-0007zi-7L for rsgb_lf_group@blacksheep.org; Mon, 08 Mar 2010 06:57:17 +0000 Received: from parrot.netcom.co.uk ([217.72.171.49]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NoWtv-0008JP-GN for rsgb_lf_group@blacksheep.org; Mon, 08 Mar 2010 06:57:17 +0000 Received: from abelian.netcom.co.uk (i-194-106-52-83.freedom2surf.net [194.106.52.83]) by parrot.netcom.co.uk (Postfix) with ESMTP id C964C3279B6 for ; Mon, 8 Mar 2010 06:54:45 +0000 (GMT) Received: from [127.0.0.1] (localhost [127.0.0.1]) by abelian.netcom.co.uk (8.13.1/8.13.1) with ESMTP id o286v8Ys012046 for ; Mon, 8 Mar 2010 06:57:09 GMT Message-ID: <4B949FC4.6070301@abelian.org> Date: Mon, 08 Mar 2010 06:57:08 +0000 From: Paul Nicholson User-Agent: Thunderbird 2.0.0.14 (X11/20080421) MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <4B8E8027.3060809@iup.uni-heidelberg.de> <4B8EC9A9.80507@abelian.org> <38A51B74B884D74083D7950AD0DD85E82A1B31@File-Server-HST.hst.e-technik.tu-darmstadt.de> <4B9203FE.3000703@abelian.org> <38A51B74B884D74083D7950AD0DD85E82A1B34@File-Server-HST.hst.e-technik.tu-darmstadt.de> <4B92300A.7090604@freenet.de> <38A51B74B884D74083D7950AD0DD85E82A1B37@File-Server-HST.hst.e-technik.tu-darmstadt.de> <4B923D2C.1030307@freenet.de> <38A51B74B884D74083D7950AD0DD85E82A1B39@File-Server-HST.hst.e-technik.tu-darmstadt.de> In-Reply-To: <38A51B74B884D74083D7950AD0DD85E82A1B39@File-Server-HST.hst.e-technik.tu-darmstadt.de> X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: VLF TX coil ready Content-Type: text/plain; charset=ISO-8859-1; format=flowed 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=0.9 required=5.0 tests=FROM_ENDS_IN_NUMS 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-global-disposition: G x-aol-sid: 3039ac1d400a4b94a03f047b X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) Stefan Sch=E4fer schrieb: > [VLF loading coil] has about 1100 turns. Average diameter is > about 0,55m, hight about 0,5m. I ran this info through a modelling program, with a guess that the wire is 26awg:- Ldc: 482mH Rdc: 258.3 ohms Resonances, unloaded, base grounded, stood vertically 10cm above a good ground with nothing within a few metres:- 1/4 wave : 46.56 kHz 3/4 wave: 121.7 kHz 5/4 wave: 195.5 kHz Adding a 100m kite, 2m diameter, raised vertically (=3D560pF) to the model, I found I needed an extra 70pF of shunt loading to bring the system into tune. The system resonances then become: 1/4 wave: 8.973 kHz 3/4 wave: 116.3 kHz 5/4 wave: 185.4 kHz Hopefully you can seal the coil before the thing warms up and the turns fall out of place! > TX power of 200W. I bet you will need more, eg 500W. Very hard to predict the Q factor obtained in the field, but it is always lower than what you hope it will be! -- Paul Nicholson --