Return-Path: X-Spam-DCC: paranoid 1169; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-0.4 required=5.0 tests=BAYES_00,HTML_40_50, HTML_MESSAGE,RATWARE_GECKO_BUILD autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id s95MFHk1005289 for ; Mon, 6 Oct 2014 00:15:18 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Xau0M-0003XZ-By for rs_out_1@blacksheep.org; Sun, 05 Oct 2014 23:10:14 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Xau0M-0003XQ-0v for rsgb_lf_group@blacksheep.org; Sun, 05 Oct 2014 23:10:14 +0100 Received: from mail-la0-f45.google.com ([209.85.215.45]) by relay1.thorcom.net with esmtps (TLSv1:RC4-SHA:128) (Exim 4.82) (envelope-from <73dk7fc@googlemail.com>) id 1Xau0G-0002cI-6B for rsgb_lf_group@blacksheep.org; Sun, 05 Oct 2014 23:10:12 +0100 Received: by mail-la0-f45.google.com with SMTP id q1so3440450lam.18 for ; Sun, 05 Oct 2014 15:10:06 -0700 (PDT) X-DKIM-Result: Domain=googlemail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlemail.com; s=20120113; h=from:message-id:date:user-agent:mime-version:to:subject:references :in-reply-to:content-type; bh=EsbUXDS+vSYHXcT+hN9R6jlHQdIfZiFZ3gLxJk46KhI=; b=sdNLqVXprDIOYlAm/FJL0xEExFK4uELLx49K7S9omPB7bDin3LhaNMfGJZ/y3Lc7+G CDy89VAqcTriQj6R2BRA99NBc7eeggVo12b11IiWvOMawtmU2/nsn0kHGiPb5gU2dJxW eEqs+h7a0Zt72DNvU4VNTwNneLwKqW29J867a65sB7v4HekNpIWhnkik3Ll1878SLCto 3H9MEFN/zm4SN97qlw4KjD4jzKzw5GNINNsAe/mhUCOiygRaWKxOGA6mt4c0vTIlSdFM pWW5J2S+SwO9swkmo76YeBvyvQmHwg08aZaLHOeOjTcB+reYGrYE1CSHqqi4p192POOU ejgA== X-Received: by 10.112.185.68 with SMTP id fa4mr19413314lbc.77.1412547006737; Sun, 05 Oct 2014 15:10:06 -0700 (PDT) Received: from [129.206.22.206] (pc206.iup.uni-heidelberg.de. [129.206.22.206]) by mx.google.com with ESMTPSA id je9sm5100008lbc.3.2014.10.05.15.10.05 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sun, 05 Oct 2014 15:10:05 -0700 (PDT) From: DK7FC <73dk7fc@googlemail.com> X-Google-Original-From: DK7FC <73dk7fc@gmail.com> Message-ID: <5431C1BC.3050208@gmail.com> Date: Mon, 06 Oct 2014 00:10:04 +0200 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: <621ECFC5FFD44C5989A1DA8C7DE6D149@AGB> <542DB6ED.1050101@psk31.plus.com> <0ED8E8831B5B4AF7B303B9D722D436B0@AGB> <542ED037.5020506@psk31.plus.com> <5431727C.3040406@psk31.plus.com> <54317AAA.90402@psk31.plus.com> <5431A0DB.80403@psk31.plus.com> <5431C102.6070007@gmail.com> In-Reply-To: <5431C102.6070007@gmail.com> X-Scan-Signature: 3efbf4053c1a70bbeb6c0a0cc657f05e Subject: LF: Re: Schumann in my garden Content-Type: multipart/alternative; boundary="------------050909090805030501030100" 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-Scanned-By: MIMEDefang 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 674 This is a multi-part message in MIME format. --------------050909090805030501030100 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit PS: Another link :-) The file https://dl.dropboxusercontent.com/u/19882028/VLF/VLF%20Garten%20in%20T%20Antenne%2005102014_2nd.WAV (576 MB) You can test your sound system by listening to the 16 2/3 Hz stuff and ELF sferics :-) Am 06.10.2014 00:06, schrieb DK7FC: > Hi ELF und sub-ELF fans, > > I have to report about very good success on reception in the ELF and > sub-ELF range. This evening arround 16 UTC i successfully received *5 > Schumann resonances * > with my T antenna in the garden in 8m above ground, 400m outside the city. > > I significantly improved the circuit: > > Higher input resistance, now 100 MOhm > Lower cut off frequency using a 3 stage LPF arround 3 kHz > also a lower cuf off frequency of the high pass now below 10 Hz > Removed the electronic parts from the breadboard and re-soldered them > on a copper board. This was essential! because there were undefined > conducting layers on the breadboard which affected the working point > of the JFET. > > New preamp: > https://dl.dropboxusercontent.com/u/19882028/VLF/20141005_162621.jpg > New schematic: > https://dl.dropboxusercontent.com/u/19882028/VLF/DK7FC%20ELF%20preamp%20V2.jpg > > Results (shown without sferic blanking) > wideband 0...24 kHz: > https://dl.dropboxusercontent.com/u/19882028/VLF/NewELF_wide_10s_1.46HzFFT.png > also showing the frequency response of the circuit > 0...1 kHz: > https://dl.dropboxusercontent.com/u/19882028/VLF/NewELF_0to1kHz_10s_1.46HzFFT.png > 0...55 Hz: > https://dl.dropboxusercontent.com/u/19882028/VLF/0...55Hz_5sperdiv_45mHzFFT_garden3rd.png > ZEVS:https://dl.dropboxusercontent.com/u/19882028/VLF/ZEVS_garden3rd.png > (not so strong this time. QRN?) > > What about these sferics below 2 kHz? Is it normal that they are so > strong? Or is it a technical problem? Can i improve the situation by > harder attenuating the spectrum above 2 kHz? At least this is what i > want to try. > > > Next ideas for improving the SNR of ZEVS and Schumann: > Increasing the R of the LPF to 2.2...3.3 MOhm > Maybe trying 1 GOhm for biasing the JFETs gate to 6V > Improving the insulation of the antenna feeds (simple cord now, > without ceramic between). > Trying to rise the antenna 1 meter > Fixing the feed point by a ceramic insulator > > 73, Stefan/DK7FC > > --------------050909090805030501030100 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit PS: Another link :-)  The file https://dl.dropboxusercontent.com/u/19882028/VLF/VLF%20Garten%20in%20T%20Antenne%2005102014_2nd.WAV (576 MB) You can test your sound system by listening to the 16 2/3 Hz stuff and ELF sferics :-)

Am 06.10.2014 00:06, schrieb DK7FC:
Hi ELF und sub-ELF fans,

I have to report about very good success on reception in the ELF  and sub-ELF range. This evening arround 16 UTC i successfully received 5 Schumann resonances with my T antenna in the garden in 8m above ground, 400m outside the city.

I significantly improved the circuit:

Higher input resistance, now 100 MOhm
Lower cut off frequency using a 3 stage LPF arround 3 kHz
also a lower cuf off frequency of the high pass now below 10 Hz
Removed the electronic parts from the breadboard and re-soldered them on a copper board. This was essential! because there were undefined conducting layers on the breadboard which affected the working point of the JFET.

New preamp: https://dl.dropboxusercontent.com/u/19882028/VLF/20141005_162621.jpg
New schematic: https://dl.dropboxusercontent.com/u/19882028/VLF/DK7FC%20ELF%20preamp%20V2.jpg

Results (shown without sferic blanking)
wideband 0...24 kHz: https://dl.dropboxusercontent.com/u/19882028/VLF/NewELF_wide_10s_1.46HzFFT.png  also showing the frequency response of the circuit
0...1 kHz: https://dl.dropboxusercontent.com/u/19882028/VLF/NewELF_0to1kHz_10s_1.46HzFFT.png
0...55 Hz: https://dl.dropboxusercontent.com/u/19882028/VLF/0...55Hz_5sperdiv_45mHzFFT_garden3rd.png
ZEVS:https://dl.dropboxusercontent.com/u/19882028/VLF/ZEVS_garden3rd.png  (not so strong this time. QRN?)

What about these sferics below 2 kHz? Is it normal that they are so strong? Or is it a technical problem? Can i improve the situation by harder attenuating the spectrum above 2 kHz? At least this is what i want to try.


Next ideas for improving the SNR of ZEVS and Schumann:
Increasing the R of the LPF to 2.2...3.3 MOhm
Maybe trying 1 GOhm for biasing the JFETs gate to 6V
Improving the insulation of the antenna feeds (simple cord now, without ceramic between).
Trying to rise the antenna 1 meter
Fixing the feed point by a ceramic insulator

73, Stefan/DK7FC


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