Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id x37AvVpp030143 for ; Sun, 7 Apr 2019 12:57:32 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1hD5Pt-0001Dx-E0 for rs_out_1@blacksheep.org; Sun, 07 Apr 2019 11:52:49 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1hD5Ps-0001Do-Jr for rsgb_lf_group@blacksheep.org; Sun, 07 Apr 2019 11:52:48 +0100 Received: from lethe.lipkowski.org ([151.80.54.59] helo=lipkowski.org) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.92) (envelope-from ) id 1hD5Pq-00027E-QQ for rsgb_lf_group@blacksheep.org; Sun, 07 Apr 2019 11:52:47 +0100 Received: from mailn.lipkowski.org (localhost [127.0.0.1]) by lipkowski.org (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id x37AnGJM027147 for ; Sun, 7 Apr 2019 12:49:16 +0200 Received: from localhost (sq5bpf@localhost) by mailn.lipkowski.org (8.14.4/8.14.4/Submit) with ESMTP id x37AnFAK027143 for ; Sun, 7 Apr 2019 12:49:16 +0200 X-Authentication-Warning: mailn.lipkowski.org: sq5bpf owned process doing -bs Date: Sun, 7 Apr 2019 12:49:15 +0200 (CEST) From: Jacek Lipkowski To: rsgb_lf_group@blacksheep.org In-Reply-To: <5CA9BD98.2030002@posteo.de> Message-ID: References: <1652663722.1033558.1554575549616.ref@mail.yahoo.com> <1652663722.1033558.1554575549616@mail.yahoo.com> <5CA90E98.2070707@posteo.de> <8c46744b-f60a-ca91-f60f-97a2f5f7b11f@abelian.org> <5CA931D4.6050908@posteo.de> <83eece37-ae11-b2fd-917c-ad29c350695b@abelian.org> <5CA9BD98.2030002@posteo.de> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 X-Spam-Score-sq5bpf: -2.9 () ALL_TRUSTED,BAYES_00 X-Scanned-By: MIMEDefang 2.75 on 10.1.3.10 X-Spam-Score: -0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: On Sun, 7 Apr 2019, DK7FC wrote: > An OM (OT!) of my radio club told stories of his early radio experiments. He > had a friend in some 100m distance and they lay out a small hidden wire into > they ground between their QTHs, using th [...] Content analysis details: (-0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_PASS SPF: sender matches SPF record -0.0 SPF_HELO_PASS SPF: HELO matches SPF record X-Scan-Signature: 0a4643e586472c13187d293ec5d096c2 Subject: Re: ULF: EbNaut message transmitted from ground loop Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed 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 On Sun, 7 Apr 2019, DK7FC wrote: > An OM (OT!) of my radio club told stories of his early radio experiments. He > had a friend in some 100m distance and they lay out a small hidden wire into > they ground between their QTHs, using the earth as the back 'wire'. Some electricity (i think they didn't call it electronics back then) hobby books for boys in the USA has descriptions of using ground dipoles for telegraphy. The transmitter was a buzzer-like circuit with step-up transformer, and the receiver was just high impedance headphones. Unfortunately i don't have the book, but i remember it also showed how to make a rhumkorff generator from a ford t ignition coil, so it must have been very old. I also remember reading somewhere that during the war (not sure it was WW II) using amateur radio equipment was prohibited, and the ARRL advised using similar equipment, so that people don't loose their operating skills. No doubt some people used much larger ground dipoles than advised in the books :) VY 73 Jacek / SQ5BPF