Return-Path: Received: from mtain-mb02.r1000.mx.aol.com (mtain-mb02.r1000.mx.aol.com [172.29.96.22]) by air-da07.mail.aol.com (v129.4) with ESMTP id MAILINDA071-85e94bf533de2fc; Thu, 20 May 2010 09:06:38 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-mb02.r1000.mx.aol.com (Internet Inbound) with ESMTP id A893C380000E7; Thu, 20 May 2010 09:06:32 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1OF5Rb-0006T5-Rx for rs_out_1@blacksheep.org; Thu, 20 May 2010 14:05:47 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1OF5Rb-0006Sv-FZ for rsgb_lf_group@blacksheep.org; Thu, 20 May 2010 14:05:47 +0100 Received: from relay.uni-heidelberg.de ([129.206.100.212]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1OF5Ra-0000P1-5b for rsgb_lf_group@blacksheep.org; Thu, 20 May 2010 14:05:47 +0100 Received: from freitag.iup.uni-heidelberg.de (freitag.iup.uni-heidelberg.de [129.206.29.204]) by relay.uni-heidelberg.de (8.14.1/8.14.1) with ESMTP id o4KD5WOr025731 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Thu, 20 May 2010 15:05:32 +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 o4KD5j58002408 for ; Thu, 20 May 2010 15:05:45 +0200 Message-ID: <4BF53399.4010403@iup.uni-heidelberg.de> Date: Thu, 20 May 2010 15:05:29 +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: <008f01caf784$779a11d0$0301a8c0@your91hoehfy9g> <4BF4FBF4.2020208@iup.uni-heidelberg.de> In-Reply-To: <4BF4FBF4.2020208@iup.uni-heidelberg.de> X-MIME-Autoconverted: from 8bit to quoted-printable by relay.uni-heidelberg.de id o4KD5WOr025731 X-Spam-Score: 1.4 (+) X-Spam-Report: autolearn=disabled,RATWARE_GECKO_BUILD=1.426 Subject: VLF: Clipping or blanking?? 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=0.0 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: 3039ac1d60164bf533d84d68 X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) Dear VLF, In Spectrum Lab there are different methods for noise reduction (e.g. of= =20 lightnings). Those were discussed here in the last weeks. While=20 Jim/M0BMU preferes the clipper (using 0 dB above AVG if i remember=20 correctly), Markus/DF6NM prefers the noise blanker. Since i do a lot of experiments with the second grabber page, checking=20 the optimal software and hardware for this=20 antenna/location/band/mode..., i have now added a 7th window that shows=20 the DFCW-600 window with a noise blanker instead of the clipper (i am=20 also using the clipper so far). So there are 7 windows running now on=20 this site:=20 http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber2.html 1: DFCW-600 with clipper (3dB above AVG) 2: DFCW-600 with noise blanker (ramp 0,002s, trigger 9dB, pulse 0,05s) 3: DFCW-60 (all others with the clipper as well) 4: DFCW-3 5: ALPHA (RSDN-20, F1) in 424=B5Hz (currently OFF) 6: DFCW-6000 7: wide band window 0...24 kHz I still have to reduce the IM in the first stage (2nd order low pass=20 filter at the output of the first stage does not better the situation),=20 either by reducing the wire length or adding a series resistor or...hm,=20 will see (any ideas?). When the IM is reduced, i want agn to transmit=20 DFCW-600 out of 1,1 km using the TV transformer. Then, one will see=20 which noise reduction method makes the best readability :-) 73, Stefan/DK7FC