Return-Path: Received: from mtain-mj09.r1000.mx.aol.com (mtain-mj09.r1000.mail.aol.com [172.21.164.93]) by air-db10.mail.aol.com (v129.4) with ESMTP id MAILINDB104-869e4ced80291e; Wed, 24 Nov 2010 16:14:17 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mj09.r1000.mx.aol.com (Internet Inbound) with ESMTP id 58BF638000077; Wed, 24 Nov 2010 16:14:16 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1PLMeF-0001Vg-CV for rs_out_1@blacksheep.org; Wed, 24 Nov 2010 21:13:03 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1PLMeE-0001VX-T4 for rsgb_lf_group@blacksheep.org; Wed, 24 Nov 2010 21:13:02 +0000 Received: from relay.uni-heidelberg.de ([129.206.100.212]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1PLMeD-00080k-FY for rsgb_lf_group@blacksheep.org; Wed, 24 Nov 2010 21:13:02 +0000 Received: from ix.urz.uni-heidelberg.de (cyrus-portal.urz.uni-heidelberg.de [129.206.100.176]) by relay.uni-heidelberg.de (8.14.1/8.14.1) with ESMTP id oAOLD0A8021909 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 24 Nov 2010 22:13:00 +0100 Received: from extmail.urz.uni-heidelberg.de (extmail.urz.uni-heidelberg.de [129.206.100.140]) by ix.urz.uni-heidelberg.de (8.13.8/8.13.8) with ESMTP id oAOLD0Mr002347 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 24 Nov 2010 22:13:00 +0100 Received: from [129.206.196.238] (vpn238a.rzuser.uni-heidelberg.de [129.206.196.238]) by extmail.urz.uni-heidelberg.de (8.13.4/8.13.1) with ESMTP id oAOLCL9Y028763 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 24 Nov 2010 22:12:22 +0100 Message-ID: <4CED7FE5.50602@iup.uni-heidelberg.de> Date: Wed, 24 Nov 2010 22:13:09 +0100 From: =?ISO-8859-1?Q?Stefan_Sch=E4fer?= User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.11) Gecko/20100711 Thunderbird/3.0.6 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <4CED6CC1.6070302@iup.uni-heidelberg.de> In-Reply-To: X-Spam-Score: 1.4 (+) X-Spam-Report: autolearn=disabled,RATWARE_GECKO_BUILD=1.426 Subject: Re: LF: new VLF antenna at DK7FC 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-global-disposition: G x-aol-sid: 3039400c89b24ced802843f8 X-AOL-IP: 195.171.43.25 X-Mailer: Unknown (No Version) Hi Roger, Am 24.11.2010 21:43, schrieb Roger Lapthorn: > Hi Stefan, > > I am unclear about the connection back to the shack. Are you using > three wires (in the CAT5 cable) then to feed power, ground and signal > back to the shack from the FET? No, i use 2 wires. One is GND and the other one is between drain of the 1st FET and its 390 Ohm resistor. > No isolation transformers etc? In the first attempt, so now, i am using no isolation transformer. Since i do not want to change the "official" grabber system but using the VLF grabber PC for the tests, i am using the internal soundcard of the PC (the official grabber uses a USB soundcard (5 Euro!)). This internal soundcard's GND is the GND of the PC and circuit, so no difference with an isolation transformer, just in this case! > Do you use this also on 136kHz and 500kHz with different filters? Currently just on VLF but i plan to do some tests on 137 kHz as well. Will inform you about the results. 73, Stefan