Return-Path: X-Spam-DCC: paranoid 1290; 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=-1.4 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, NO_REAL_NAME,SPF_PASS 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 u984lPBn006624 for ; Sat, 8 Oct 2016 06:47:25 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1bsjU3-0000LK-Ov for rs_out_1@blacksheep.org; Sat, 08 Oct 2016 05:43:39 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1bsjU3-0000LB-1P for rsgb_lf_group@blacksheep.org; Sat, 08 Oct 2016 05:43:39 +0100 Received: from simone.ucs.mun.ca ([134.153.232.76]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.87) (envelope-from ) id 1bsjU0-0002vi-SQ for rsgb_lf_group@blacksheep.org; Sat, 08 Oct 2016 05:43:37 +0100 Received: from plato.ucs.mun.ca (plato.ucs.mun.ca [134.153.232.153]) by simone.ucs.mun.ca (8.13.8/8.13.8) with ESMTP id u984hR86010585 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Sat, 8 Oct 2016 02:13:31 -0230 Date: Sat, 8 Oct 2016 02:13:28 -0230 (NDT) From: jcraig@mun.ca X-X-Sender: jcraig@plato.ucs.mun.ca To: rsgb_lf_group@blacksheep.org In-Reply-To: <57F83029.8010104@posteo.de> Message-ID: References: <154c32c4dba-373a-24653@webprd-m58.mail.aol.com> <573CAF79.9040701@abelian.org> <573CBBF0.4030701@posteo.de> <573E5907.6020107@posteo.de> <573EA094.3040205@abelian.org> <573EF90F.1080201@posteo.de> <573FC4DA.3080107@abelian.org> <5740842D.3030000@posteo.de> <5744FA27.6010703@posteo.de> <57F56531.3060205@posteo.de> <57F78A3F.5030803@posteo.de> <57F80D22.2020800@posteo.de> <57F83029.8010104@posteo.de> MIME-Version: 1.0 X-Scan-Signature: 046f068074e745d5c60ca47deee9b503 Subject: Re: ULF: A new step on the large ULF coil... Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed 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 10.1.3.11 Status: RO X-Status: X-Keywords: X-UID: 8964 Fascinating indeed Stefan. Keep up the good work! 73 Joe VO1NA On Sat, 8 Oct 2016, DK7FC wrote: > Hi ULF, > > This night i have completed the 4th stack of my large *ULF loading coil*. > An image: > *https://dl.dropboxusercontent.com/u/19882028/ULF/20161008_ULF_TX_coil.jpg* > > The exciting question was, what is the new resonance frequency together with > my antenna. In the lab i put an equivalent C in parallel and found the > resonance peak at *3.67 kHz*. So the L seems to be *3.8 H* now. This is still > not enough. The l/d of the coil dimension becomes larger now, so i need more > and more wire to reach the final resonance frequency of 2.97 kHz at about 500 > pF. > > I will do a next test on the actual resonance frequency in some days, when > the WX permits. I will also check where the resonance can be found when > switching the small coil in series that i use for 6.47 kHz now. It could be > quite close to 2.97 kHz then! So maybe this allows a next QRO step on 2.97 > kHz: 100 mA antenna current must be reached for the planned experiment in 65 > km distance. > > BTW the 4 stack coil is wound out of almost 4 kg of enameled Cu wire with 0.4 > mm diameter. The layers are isolated by Kapton tape. My assumption is that it > will hold 20 kV now. > Ah and the *DC resistance is 445 Ohm* now. When connecting 275 V AC / 50 Hz, > i can measure 269 mA. So the actual inductance is *2.93 H* (beeing farer away > from the self resonance frequency) > > I can tell you it's quite fascinating to operate down on these low > frequencies :-) To be continued... > > 73, Stefan/DK7FC >