Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-0.7 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_MED,SPF_PASS,SUBJ_ALL_CAPS autolearn=ham autolearn_force=no version=3.4.0 X-Spam-DCC: : mailn 1480; Body=3 Fuz1=3 Fuz2=3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by lipkowski.org (8.14.4/8.14.4/Debian-8+deb8u1) with ESMTP id v1FLuc61002157 for ; Wed, 15 Feb 2017 22:56:39 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ce7Ut-0001OY-So for rs_out_1@blacksheep.org; Wed, 15 Feb 2017 21:52:23 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ce7Ut-0001OP-2N for rsgb_lf_group@blacksheep.org; Wed, 15 Feb 2017 21:52:23 +0000 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 1ce7Uq-0003NT-2u for rsgb_lf_group@blacksheep.org; Wed, 15 Feb 2017 21:52:21 +0000 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 v1FLqAKX031758 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 15 Feb 2017 18:22:15 -0330 Date: Wed, 15 Feb 2017 18:22:10 -0330 (NST) From: jcraig@mun.ca X-X-Sender: jcraig@plato.ucs.mun.ca To: rsgb_lf_group@blacksheep.org In-Reply-To: <58A4B3C9.4030007@posteo.de> Message-ID: References: <15a42e15605-3718-97d8@webprd-a49.mail.aol.com> <58A4A5FB.7040000@posteo.de> <58A4B3C9.4030007@posteo.de> MIME-Version: 1.0 X-Scan-Signature: 33d261536bb1467bb13d5764461d5ec4 Subject: Re: VLF: VO1NA 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 2.75 Status: RO X-Status: X-Keywords: X-UID: 10605 Hi Stefan, I'm not sure how much voltage the coil will take. So far, there is no smell of ozone or burnt insulation. Coils wound with 6 strands would arc and short with more than 20 ma. So far the 12 strand coils are fine with 20 ma. The 0.08mm wire is very long and very inexpensive and available, unlike 0.4 mm. It isn't really litz as it's only twisted together and not cabled of bundles of 3. Perhaps its AC losses are lower than a single conductor of equivalent cross section. The DC resistance is about twice that of 0.4 mm. I think the skin depth at 8 kHz is 0.7 mm so 0.4 mm is an ideal diam if a 2 km length is available! 73 and congrats again on your inspiring VLF/ULF transmissions. Joe On Wed, 15 Feb 2017, DK7FC wrote: > Hi Joe, > > How much current or voltage will the coils hold? > Why did you choose RF litz wire for a VLF TX coil? > Good luck! > > 73, Stefan > > Am 15.02.2017 20:45, schrieb jcraig@mun.ca: >> Hi VLF, >> >> Thank-you for the interesting reading and congrats on your latest >> milestones. >> >> There have been some very modest steps taken on this side of the >> pond. New coils were wound with 12 strands of 0.08mm insulated >> copper: 2 pies 170 and 110 mH, combined 487 mH, 234 ohms DC. >> The 100m wire at H=15m was just tuned and I'm happy to be QRV again >> on VLF a month after the licence was renewed. >> >> 73 >> Joe VO1NA > >