Return-Path: Received: from mtain-da10.r1000.mx.aol.com (mtain-da10.r1000.mx.aol.com [172.29.64.82]) by air-md05.mail.aol.com (v129.4) with ESMTP id MAILINMD054-8b874bf3b65283; Wed, 19 May 2010 05:58:42 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-da10.r1000.mx.aol.com (Internet Inbound) with ESMTP id 05D1738000085; Wed, 19 May 2010 05:58:40 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1OEg22-0003LA-Ch for rs_out_1@blacksheep.org; Wed, 19 May 2010 10:57:42 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1OEg22-0003L1-0X for rsgb_lf_group@blacksheep.org; Wed, 19 May 2010 10:57:42 +0100 Received: from relay2.uni-heidelberg.de ([129.206.210.211]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1OEg1z-000292-TH for rsgb_lf_group@blacksheep.org; Wed, 19 May 2010 10:57:41 +0100 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 o4J9vPbW008725 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 19 May 2010 11:57:25 +0200 Received: from [129.206.29.99] (pc99.iup.uni-heidelberg.de [129.206.29.99]) by freitag.iup.uni-heidelberg.de (8.12.11.20060308/8.11.2) with ESMTP id o4J9vc5p017557 for ; Wed, 19 May 2010 11:57:39 +0200 Message-ID: <4BF3B602.9090104@iup.uni-heidelberg.de> Date: Wed, 19 May 2010 11:57:22 +0200 From: =?ISO-8859-1?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: <002701caf394$44cbd980$0401a8c0@xphd97xgq27nyf> <4BEE8B1B.502@iup.uni-heidelberg.de> <4BEE92AD.7090909@iup.uni-heidelberg.de> <38A51B74B884D74083D7950AD0DD85E82A1BF2@File-Server-HST.hst.e-technik.tu-darmstadt.de> <38A51B74B884D74083D7950AD0DD85E82A1BF3@File-Server-HST.hst.e-technik.tu-darmstadt.de> <584F52DF3AAC487DBCD36E94942FDA22@JimPC> <4BF27269.2020603@iup.uni-heidelberg.de> <46148C4AA5164D30B4E3186D6C534215@JimPC> <4BF3AD47.4030404@iup.uni-heidelberg.de> In-Reply-To: <4BF3AD47.4030404@iup.uni-heidelberg.de> X-Spam-Score: 1.4 (+) X-Spam-Report: autolearn=disabled,RATWARE_GECKO_BUILD=1.426 Subject: VLF: 2nd test grabber 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: 3039ac1d40524bf3b6503802 X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) VLF, Just for the small group of VLF grabber interested OMs: To check the new location for my grabber i have set up a second grabber page that displays the signals of the test setup antenna with fiber optic cables. The page will be active just for some weeks. It is to compare differnt antenna (filter, input stage...) designs and earthing methods, also the QRM/QRN situation at this location. Further, one can compare the daily QRM/QRN minima and maxima there. It seems there is still a problem with IM in the first stage although i have added a band pass filter in the first stage (replaced the 100 Ohm resistor by a 3,3mH inductance (RDC=50 Ohm)). This suppresses the 50 Hz components and allows even 6 dB voltage gain for 9 kHz but it seems i need a low pass on the gate side, as DJ1ZB suggested. The levels of the BCD stns in the LF sector is extreme there, abt 20dB higher than at the current grabber(1) RX... Link of the 2nd temporarely grabber2: http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber2.html 73, Stefan/DK7FC PS: I have also added a wide band window, just as Markus has done it (still different scroll times but i will change that today).