Return-Path: Received: from mtain-mh09.r1000.mx.aol.com (mtain-mh09.r1000.mx.aol.com [172.29.96.221]) by air-da06.mail.aol.com (v129.4) with ESMTP id MAILINDA063-863e4be862c630; Mon, 10 May 2010 15:47:19 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-mh09.r1000.mx.aol.com (Internet Inbound) with ESMTP id 938CD380000BD; Mon, 10 May 2010 15:47:16 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1OBYvB-0000xV-H6 for rs_out_1@blacksheep.org; Mon, 10 May 2010 20:45:45 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1OBYvA-0000xM-VW for rsgb_lf_group@blacksheep.org; Mon, 10 May 2010 20:45:44 +0100 Received: from smtp03.online.nl ([194.134.41.33]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1OBYv8-0001tg-Id for rsgb_lf_group@blacksheep.org; Mon, 10 May 2010 20:45:44 +0100 Received: from smtp03.online.nl (localhost [127.0.0.1]) by smtp03.online.nl (Postfix) with ESMTP id BB5C668278 for ; Mon, 10 May 2010 21:45:36 +0200 (CEST) Received: from pa3fnytrqxpddu (s5593e077.adsl.wanadoo.nl [85.147.224.119]) by smtp03.online.nl (Postfix) with SMTP for ; Mon, 10 May 2010 21:45:36 +0200 (CEST) From: To: Date: Mon, 10 May 2010 21:45:36 +0200 Message-ID: MIME-Version: 1.0 X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2911.0) In-Reply-To: <4BE855F1.9050909@iup.uni-heidelberg.de> Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-Online-Scanned: by Cloudmark authority (on smtp03.online.nl) X-Spam-Score: 0.8 (/) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001,MAILTO_TO_SPAM_ADDR=0.276,NO_REAL_NAME=0.55 Subject: RE: LF: RE: 8,97 kHz active antenna circuit and pictures Content-Type: multipart/alternative; boundary="----=_NextPart_000_0004_01CAF08A.20014E30" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: *** X-Spam-Status: No, hits=3.7 required=5.0 tests=FROM_ENDS_IN_NUMS,HTML_30_40, HTML_FONTCOLOR_BLUE,HTML_MESSAGE,HTML_TITLE_EMPTY,MAILTO_TO_SPAM_ADDR, NO_REAL_NAME 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: 3039ac1d60dd4be862c464e3 X-AOL-IP: 193.82.116.20 ------=_NextPart_000_0004_01CAF08A.20014E30 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hello Stefan,lf glad to hear you solved the problem and your grabber is now much more sensitive,maby some manmade signals will pop up... I had the same problem here with 675 KHz (7Km away) together with 1008= and 747 KHz,this gave products at 333 and 72 KHz.. 73 Victor PS building a new ocxo controlled rx for lf,mf and topband,single conv= ersion with 1.4MHz if. -----Oorspronkelijk bericht----- Van: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org]Namens Stefan Sch=E4fer Verzonden: maandag 10 mei 2010 20:53 Aan: rsgb_lf_group@blacksheep.org Onderwerp: Re: LF: RE: 8,97 kHz active antenna circuit and pictures Hello Victor, LF, It took a little bit to reply to your answer. You have been absolute= ly right! DLF(153kHz) is here just some 10km away and the strong french= LF broadcast station on 162kHz has caused the nonlinear working of my fir= st stage i assume. Yesterday i talked with Markus/DF6NM and he gave me th= e very useful hint to add a C between drain and gnd of the first stage (what= forms a low pass with the drain R). Before some minutes i added a 100nF capa= citor, so the edge frequency should be about 15kHz. Before that, i have looke= d on a second experimental active E field antenna how it influences the gain= on the dreamers band (almost no difference). But see the S/N improvement NOW= on my grabber (http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber.html)= ! What a big difference!!! :-))))) So happy about that! :-) Tnx to Markus and you, Victor! 73, Stefan/DK7FC PS: I have built a small TX antenna at my new home QTH in Heidelberg= . With a TV transformer and my 300W PA (running at 15W DC input) i apply abou= t 2kV rms on a 10m horizontal wire, about 3m above gnd. The distance to the grabber here is 1,1km. Hopefully i can see something, at least in DFCW-600... Am 28.04.2010 15:51, schrieb victor13@online.nl: Hi Stefan, looks nice but I suspect you have some im problem in your first= stage because off the strong line at 9 KHz,Maby it's better to use a filter= at the input.... 73 Victor -----Oorspronkelijk bericht----- Van: Stefan Sch=E4fer [mailto:owner-rsgb_lf_group@blacksheep.org= ]Namens Stefan Sch=E4fer Verzonden: woensdag 28 april 2010 12:50 Aan: rsgb_lf_group@blacksheep.org Onderwerp: VLF: 8,97 kHz active antenna circuit and pictures Dear LF, Daniele and others asked for the circuit of my active E field an= tenna that i am using for my grabber. Now i have created a pdf file where yo= u can find the circuit and a picture of the arrangement and a spectrogram of= the currently working circuit. http://www.iup.uni-heidelberg.de/schaefer_vlf/8,97kHz%20active%2= 0E%20f ield%20antenna%20by%20DK7FC.pdf So, if you are interested or want to get some ideas for your own circuit, take a look on it. I hope the link works. So, best 73 and maybe cu this evening there, dreamers. Stefan/DK7FC ------=_NextPart_000_0004_01CAF08A.20014E30 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hello=20 Stefan,lf
 
glad=20 to hear you solved the problem and your grabber is now much more sensi= tive,maby=20 some manmade signals will pop up...
I had=20 the same problem here with 675 KHz (7Km away) together with 1008 and= 747=20 KHz,this gave products at 333 and 72 KHz..
 
73
Victor
 
PS=20 building a new ocxo controlled rx for lf,mf and topband,single convers= ion with=20 1.4MHz if.
-----Oorspronkelijk bericht-----
Van:= =20 owner-rsgb_lf_group@blacksheep.org=20 [mailto:owner-rsgb_lf_group@blacksheep.org]Namens Stefan=20 Sch=E4fer
Verzonden: maandag 10 mei 2010 20:53
Aan:<= /B>=20 rsgb_lf_group@blacksheep.org
Onderwerp: Re: LF: RE: 8,97= kHz active=20 antenna circuit and pictures

Hello Victor, LF,
It=20 took a little bit to reply to your answer. You have been absolutely= right!=20 DLF(153kHz) is here just some 10km away and the strong french LF bro= adcast=20 station on 162kHz has caused the nonlinear working of my first stage= i assume.=20 Yesterday i talked with Markus/DF6NM and he gave me the very useful= hint to=20 add a C between drain and gnd of the first stage (what forms a low= pass with=20 the drain R). Before some minutes i added a 100nF capacitor, so the= edge=20 frequency should be about 15kHz. Before that, i have looked on a sec= ond=20 experimental active E field antenna how it influences the gain on th= e dreamers=20 band (almost no difference). But see the S/N improvement NOW on my= grabber (http://www.= iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber.html)!=20 What a big difference!!! :-)))))
So happy about that! :-)
Tnx= to Markus=20 and you, Victor!

73, Stefan/DK7FC

PS: I have built a= small TX=20 antenna at my new home QTH in Heidelberg. With a TV transformer and= my 300W PA=20 (running at 15W DC input) i apply about 2kV rms on a 10m horizontal= wire,=20 about 3m above gnd. The distance to the grabber here is 1,1km. Hopef= ully i can=20 see something, at least in DFCW-600...




Am 28.04.2= 010 15:51,=20 schrieb victor13@online.nl:=20
Hi=20 Stefan,
 
looks nice but I suspect you  have some im= problem in your first=20 stage because off the strong line at 9 KHz,Maby it's better to use= a filter=20 at the input....
 
73
 
Victor
-----Oorspronkelijk bericht-----
Van: Stefan Sch=E4fer [mailto:own= er-rsgb_lf_group@blacksheep.org]Namens=20 Stefan Sch=E4fer
Verzonden: woensdag 28 april 2010= =20 12:50
Aan: rsgb_lf_group@blackshe= ep.org
Onderwerp:=20 VLF: 8,97 kHz active antenna circuit and pictures

=

Dear LF,

Daniele and others asked for the circuit of= my active=20 E field antenna that i am using for my grabber. Now i have creat= ed a pdf=20 file where you can find the circuit and a picture of the arrange= ment and a=20 spectrogram of the currently working circuit.

http://www.iup.uni-heidelberg.de/schaefer_vlf/8,97kHz%20act= ive%20E%20field%20antenna%20by%20DK7FC.pdf

So,=20 if you are interested or want to get some ideas for your own cir= cuit, take=20 a look on it. I hope the link works.

So, best 73 and mayb= e cu this=20 evening there,=20 dreamers.

Stefan/DK7FC

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