Return-Path: Received: from mtain-di04.r1000.mx.aol.com (mtain-di04.r1000.mx.aol.com [172.29.64.8]) by air-db05.mail.aol.com (v129.4) with ESMTP id MAILINDB054-86994c7f74b58c; Thu, 02 Sep 2010 05:56:05 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-di04.r1000.mx.aol.com (Internet Inbound) with ESMTP id 1F40838000091; Thu, 2 Sep 2010 05:56:03 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Or6VB-0000dK-BV for rs_out_1@blacksheep.org; Thu, 02 Sep 2010 10:54:37 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Or6VA-0000dB-QM for rsgb_lf_group@blacksheep.org; Thu, 02 Sep 2010 10:54:36 +0100 Received: from relay.uni-heidelberg.de ([129.206.100.212]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Or6V4-0006Ml-JS for rsgb_lf_group@blacksheep.org; Thu, 02 Sep 2010 10:54:36 +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 o829s1Rt028174 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Thu, 2 Sep 2010 11:54:01 +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 o829sTVd027211 for ; Thu, 2 Sep 2010 11:54:29 +0200 Message-ID: <4C7F73EC.6030405@iup.uni-heidelberg.de> Date: Thu, 02 Sep 2010 11:52:44 +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: <000a01cb493d$fb8f3410$0401a8c0@xphd97xgq27nyf> <4C7E2046.536.2C4F91@v.d.heide.on-line.de> <002501cb49f0$acabccb0$0401a8c0@xphd97xgq27nyf> <4C7E8D66.2030806@gmx.com> <004701cb49fd$25f18590$0401a8c0@xphd97xgq27nyf> <4C7F639F.1040501@iup.uni-heidelberg.de> In-Reply-To: X-Spam-Score: 1.4 (+) X-Spam-Report: autolearn=disabled,HTML_MESSAGE=0.001,RATWARE_GECKO_BUILD=1.426 Subject: Re: ELF: ELF! Content-Type: multipart/alternative; boundary="------------040802070803000108020603" 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=HTML_MESSAGE 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: 3039ac1d40084c7f74b34bb5 X-AOL-IP: 193.82.116.20 X-AOL-SPF: domain : blacksheep.org SPF : none X-Mailer: Unknown (No Version) --------------040802070803000108020603 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable X-MIME-Autoconverted: from 8bit to quoted-printable by relay.uni-heidelberg.de id o829s1Rt028174 Tnx Roger, Yes, my earth antenna is near field. Thus i am optimistic to see my=20 signal there which might give first impressions about the performance of= =20 the antenna and so. Since i am > 30 dB above noise in 40,0 km distance=20 (/p kite QTH to my VLF grabber) at 8,97 kHz and at 6,47 kHz and we are=20 going to the winther period i am optimistic to see the trace at least=20 there. Maybe some more km can be reached. This can be estimated after=20 knowing the S/N on my grabber, which is in the far field :-) Hopefully=20 the RX density in Germany increases soon :-) 73, Stefan Am 02.09.2010 11:02, schrieb Roger Lapthorn: > Good luck Stefan. > > It will be most interesting to see how far you can get without the=20 > assistance of "utilities conduction" as was the case with my own small= =20 > tests in the summer. If my understanding is right you have to get=20 > beyond about 25km to be in the far field at this sort of frequency, so= =20 > reception at 40km is a good target. I wonder if the effective loop=20 > size (in the ground) increases because of the increasing skin depth=20 > and signal penetration? If so, the results might be better than expected= . > > I can look at these frequencies with the kit I've already used, but=20 > doubt I'd see anything. > > 73s > Roger G3XBM > > > 2010/9/2 Stefan Sch=E4fer > > > Dear LF/VLF, > > Am 01.09.2010 19:43, schrieb mal hamilton: > > Miracles are possible but impossibilities take a little longer. > > > Yes. Thus is just want to announce some tests on ELF, probably > arround 2 kHz. First i set up a grabber window for ELF, still with > the VLF active antenna. I will built an ELF active antenna soon > (some weeks). First tests will be done with the earth antenna (5 > km), later i plan to reach 40 km with the 200m or 300m antenna > (using some parallel Cs or even a mains HV transformer?). Maybe > some interesting effects will come up... Distances will most > probably not reach to UK or so but who knows (before some weeks, > no one belived that it is possible to reach almost 50 km with an > earth antenna at moderate TX power). > > Will there be any interested OMs for that project? > > > 73, Stefan/DK7FC > > > > > --=20 > http://g3xbm-qrp.blogspot.com/ > http://www.g3xbm.co.uk > http://www.youtube.com/user/g3xbm > G3XBM GQRP 1678 ISWL G11088 --------------040802070803000108020603 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Tnx Roger,

Yes, my earth antenna is near field. Thus i am optimistic to see my signal there which might give first impressions about the performance of the antenna and so. Since i am > 30 dB above noise in 40,0 km distance (/p kite QTH to my VLF grabber) at 8,97 kHz and at 6,47 kHz and we are going to the winther period i am optimistic to see the trace at least there. Maybe some more km can be reached. This can be estimated after knowing the S/N on my grabber, which is in the far field :-) Hopefully the RX density in Germany increases soon :-)

73, Stefan



Am 02.09.2010 11:02, schrieb Roger Lapthorn:
Good luck Stefan.

It will be most interesting to see how far you can get without the assistance of "utilities conduction" as was the case with my own small tests in the summer.  If my understanding is right you have to get beyond about 25km to be in the far field at this sort of frequency, so reception at 40km is a good target. I wonder if the effective loop size (in the ground) increases because of the increasing skin depth and signal penetration? If so, the results might be better than expected.

I can look at these frequencies with the kit I've already used, but doubt I'd see anything.

73s
Roger G3XBM
 

2010/9/2 Stefan Schäfer <Stefan.Schaefer@iup.uni-heidelberg.de>
Dear LF/VLF,

Am 01.09.2010 19:43, schrieb mal hamilton:
Miracles are possible but impossibilities take a little longer.

Yes. Thus is just want to announce some tests on ELF, probably arround 2 kHz. First i set up a grabber window for ELF, still with the VLF active antenna. I will built an ELF active antenna soon (some weeks). First tests will be done with the earth antenna (5 km), later i plan to reach 40 km with the 200m or 300m antenna (using some parallel Cs or even a mains HV transformer?). Maybe some interesting effects will come up... Distances will most probably not reach to UK or so but who knows (before some weeks, no one belived that it is possible to reach almost 50 km with an earth antenna at moderate TX power).

Will there be any interested OMs for that project?


73, Stefan/DK7FC




--
http://g3xbm-qrp.blogspot.com/
http://www.g3xbm.co.uk
http://www.youtube.com/user/g3xbm
G3XBM   GQRP 1678    ISWL G11088
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