Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-df02.r1000.mx.aol.com (Internet Inbound) with ESMTP id 7FAC038000092; Sun, 13 Jan 2013 10:21:12 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1TuPM7-00009s-C3 for rs_out_1@blacksheep.org; Sun, 13 Jan 2013 15:20:15 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1TuPM6-00009j-VL for rsgb_lf_group@blacksheep.org; Sun, 13 Jan 2013 15:20:14 +0000 Received: from relay2.uni-heidelberg.de ([129.206.210.211]) by relay1.thorcom.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.77) (envelope-from ) id 1TuPM4-0001HO-6Q for rsgb_lf_group@blacksheep.org; Sun, 13 Jan 2013 15:20:13 +0000 Received: from freitag.iup.uni-heidelberg.de (freitag.iup.uni-heidelberg.de [129.206.29.204]) by relay2.uni-heidelberg.de (8.13.8/8.13.8) with ESMTP id r0DFKBHm005384 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Sun, 13 Jan 2013 16:20:11 +0100 Received: from [129.206.22.206] (pc206.iup.uni-heidelberg.de [129.206.22.206]) by freitag.iup.uni-heidelberg.de (8.12.11.20060308/8.11.2) with ESMTP id r0DFKB6V018706 for ; Sun, 13 Jan 2013 16:20:11 +0100 Message-ID: <50F2D0A5.4070806@iup.uni-heidelberg.de> Date: Sun, 13 Jan 2013 16:20:05 +0100 From: =?ISO-8859-15?Q?Stefan_Sch=E4fer?= User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <50F1BC6E.9090405@iup.uni-heidelberg.de> <427C8E7C302341129739C903AAC04464@GaryAsus> <50F28C3F.3060405@xs4all.nl> In-Reply-To: <50F28C3F.3060405@xs4all.nl> X-Spam-Score: -2.3 (--) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Hi Albert and Gary, Yes, here it is the same. The detuning due to wet soil is higher than on LF. Also the relative rise of the resistive losses are higher than on LF. It can make up to 3 dB here. Now i think about a switch that allows to switch from LF to MF remotely. The idea is that the LF coil remains connected to the antenna (i.e. is not switched), only the MF coil would be switched in parallel. There will be some reactive current through the LF coil when operating on MF but it can be compensated and the losses will be low. I still did no calculations. At least the MF voltages and currents are quite low compared to LF... [...] Content analysis details: (-2.3 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at http://www.dnswl.org/, medium trust [129.206.210.211 listed in list.dnswl.org] -0.0 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain X-Scan-Signature: f62c7cf8eeb8e5a327b71719e9bffff1 Subject: Re: LF: Re: MF variometer Content-Type: text/plain; charset=ISO-8859-15; 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-global-disposition: G x-aol-sid: 3039ac1d40d650f2d0e73aef X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Hi Albert and Gary, Yes, here it is the same. The detuning due to wet soil is higher than on LF. Also the relative rise of the resistive losses are higher than on LF. It can make up to 3 dB here. Now i think about a switch that allows to switch from LF to MF remotely. The idea is that the LF coil remains connected to the antenna (i.e. is not switched), only the MF coil would be switched in parallel. There will be some reactive current through the LF coil when operating on MF but it can be compensated and the losses will be low. I still did no calculations. At least the MF voltages and currents are quite low compared to LF... 73, Stefan/DK7FC Am 13.01.2013 11:28, schrieb Albert W: > Hello Stefan es Gary, > > The same here depending on weather conditions and of course frequency > change, using a relative small variometer (DC-motor adjustable from > the shack) in series with the fixed L. > > 73, Albert PA0A > > > > >