Return-Path: Received: from mtain-mj12.r1000.mx.aol.com (mtain-mj12.r1000.mail.aol.com [172.21.164.96]) by air-mb02.mail.aol.com (v128.2) with ESMTP id MAILINMB023-a1914bc773ecab; Thu, 15 Apr 2010 16:15:40 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-mj12.r1000.mx.aol.com (Internet Inbound) with ESMTP id 9BE08380000AD; Thu, 15 Apr 2010 16:15:38 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1O2VSS-0005Z0-SP for rs_out_1@blacksheep.org; Thu, 15 Apr 2010 21:14:40 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1O2VSS-0005Yr-ET for rsgb_lf_group@blacksheep.org; Thu, 15 Apr 2010 21:14:40 +0100 Received: from mailout01.t-online.de ([194.25.134.80]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1O2VSP-0006va-Tw for rsgb_lf_group@blacksheep.org; Thu, 15 Apr 2010 21:14:40 +0100 Received: from fwd05.aul.t-online.de (fwd05.aul.t-online.de ) by mailout01.t-online.de with smtp id 1O2VSO-00038u-PD; Thu, 15 Apr 2010 22:14:36 +0200 Received: from e7010 (rfYshUZlgh6UpJv-WeQ+h2lhOrkqe+2-NGiTZXjme-Z6x6N-r5BRLxAFqhhw5FKZVG@[84.147.200.51]) by fwd05.aul.t-online.de with smtp id 1O2VSN-2AU0y80; Thu, 15 Apr 2010 22:14:35 +0200 Message-ID: <000501cadcd8$53ef5180$6402a8c0@e7010> From: "Walter und Marianne Staubach" To: References: <4D95FB39404AA04CA998E7F63B1A2E5F0432C756@esealmw110.eemea.ericsson.se> <4BC71C8D.1000508@iup.uni-heidelberg.de> <4D95FB39404AA04CA998E7F63B1A2E5F0432C7CF@esealmw110.eemea.ericsson.se> <4BC74643.1030802@iup.uni-heidelberg.de> Date: Thu, 15 Apr 2010 22:15:00 +0200 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4927.1200 X-MimeOLE: Produced By Microsoft MimeOLE V5.50.4927.1200 X-ID: rfYshUZlgh6UpJv-WeQ+h2lhOrkqe+2-NGiTZXjme-Z6x6N-r5BRLxAFqhhw5FKZVG X-TOI-MSGID: 80c3e2f1-1ae7-4196-af02-c705fb92d8e8 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,UNPARSEABLE_RELAY=0.001 Subject: LF: Re: 8,97kHz / dreamers band grabber, another one... Content-Type: text/plain; charset="iso-8859-1" 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: 3039400c89b84bc773ea555f X-AOL-IP: 193.82.116.20 Content-Transfer-Encoding: quoted-printable Lieber Stefan, woher kommt die recht starke Linie auf 8971,5 auf Deinem Gra= bber? Ich dachte schon, Du w=FCrdest mit Deinem Grabber QRSS machen. Vorn sieht das aus wie "DE". 73 Walter DJ2LF / DI2AG ----- Original Message ----- From: "Stefan Sch=E4fer" To: Sent: Thursday, April 15, 2010 7:00 PM Subject: VLF: 8,97kHz / dreamers band grabber, another one... > Der VLF dreamers, LF, > > I am glad to present you my new (and first) grabber for the dreamers > band! It is running (in the web) not even one hour! > > Take a look at: > http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber.html > > Next, i will add a ALPHA beacon window as well. > > The grabber accuracy is that of the soundcard (one time calibrated= with > SpecLab to the ALPHA stns). > > Many thanks to Markus/DF6NM and Wolfgang/DL4YHF for the support to > become QRV. Also tnx to my professor who allowed me to host the page > directly on our institutes server (makes it easy and secure to uploa= d > the pictures). > > The grabber works with an active E-field antenna (Daniele, i can giv= e > you the circuit if you want) using 2x BF862 and a 500Hz band filter > arround 9 kHz. > > BTW: The input had a 1 MOhm Resistor to prevent static overvoltages= to > the gate. Therefore the highpass edge frequency of the input C (abt= 3pF) > and R=3D 1MOhm was about 55kHz. This afternoon i changed this resist= or to > 22MOhm, giving a edge frequency of abt 2,4 kHz. The difference can= be > seen now on the upper picture. In the left side you can see the sign= al > of yesterday, in the middle i shut down the preamp to charge the bat= tery > and in the right part you see the signal with the 22MOhm resistor.= I > have not changed the volume level or QTH, just the supply voltage by > <1V. So, using a high R resistor, well above 1MOhm makes sense on VL= F! > On LF(137), 1MOhm is fine! > > The preamp is fed by a 3,4 Ah battery. This has to be charged each= 2 > days. So, i will take a solar cell ( i have many 21V/55Wp) to keep= the > supply decoupled from the local earth. I use RG174 and a AF decoupli= ng > transformer. Now, the antenna is placed temporarely in the 2nd floor= . > Since everything seems to be OK i will place it on the roof of the > building, in the 7th floor. Then, i will probably use the fiber opti= cal > cable to further reduce the local noise and prevent HV problems due= to > lightnings! > > Distance to my /p QTH is abt 37km, so i think i can write a message= in > DFCW60 without any problems. > > BTW: This weekend i wanted to do the next experiment but the wind > forecast is not very promising! But we will see... The 600W PA is re= ady > to use! So, 1000km could be cracked? :-) > > Wish you fun and motivation to improve everything in the LF/VLF worl= d :-) > > 73, Stefan/DK7FC > > > >