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 v1FM6vuG002194 for ; Wed, 15 Feb 2017 23:06:58 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ce7fz-0001W7-LI for rs_out_1@blacksheep.org; Wed, 15 Feb 2017 22:03:51 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ce7fz-0001Vy-As for rsgb_lf_group@blacksheep.org; Wed, 15 Feb 2017 22:03:51 +0000 Received: from mout02.posteo.de ([185.67.36.66]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.87) (envelope-from ) id 1ce7fw-0003So-A6 for rsgb_lf_group@blacksheep.org; Wed, 15 Feb 2017 22:03:50 +0000 Received: from submission (posteo.de [89.146.220.130]) by mout02.posteo.de (Postfix) with ESMTPS id 1382E20BB0 for ; Wed, 15 Feb 2017 23:03:46 +0100 (CET) Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 3vNtbQ4FTKz104Z for ; Wed, 15 Feb 2017 23:03:46 +0100 (CET) Message-ID: <58A4D042.8040808@posteo.de> Date: Wed, 15 Feb 2017 23:03:46 +0100 From: DK7FC 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: <15a42e15605-3718-97d8@webprd-a49.mail.aol.com> <58A4A5FB.7040000@posteo.de> <58A4B3C9.4030007@posteo.de> In-Reply-To: X-Scan-Signature: 195b836cb7437e99aa05107459888659 Subject: Re: VLF: VO1NA Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit 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: 10607 Thanks Joe, OK, 20 mA. Guess that's the strongest signal you radiated so far. Probably Paul would like to have a stable carrier for hours! :-) 234 Ohm DC, that's ok! What are the mechanical dimensions? And where are you transmitting now and what type of frequency generation are you using? 73, Stefan Am 15.02.2017 22:52, schrieb jcraig@mun.ca: > 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 >> >> >