Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=5.0 tests=FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_MED,SPF_PASS, T_DKIM_INVALID 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 uBTAXE8a031956 for ; Thu, 29 Dec 2016 11:33:15 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1cMXsw-0002gT-2O for rs_out_1@blacksheep.org; Thu, 29 Dec 2016 10:24:34 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1cMXsv-0002gK-AW for rsgb_lf_group@blacksheep.org; Thu, 29 Dec 2016 10:24:33 +0000 Received: from resqmta-ch2-10v.sys.comcast.net ([2001:558:fe21:29:69:252:207:42]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.87) (envelope-from ) id 1cMXss-0007qE-Af for rsgb_lf_group@blacksheep.org; Thu, 29 Dec 2016 10:24:32 +0000 Received: from resomta-ch2-20v.sys.comcast.net ([69.252.207.116]) by resqmta-ch2-10v.sys.comcast.net with SMTP id MXsoceMeJrC25MXsoczJyR; Thu, 29 Dec 2016 10:24:26 +0000 X-DKIM-Result: Domain=comcast.net Result=Signature OK DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=comcast.net; s=q20161114; t=1483007066; bh=IKsCpYz8hUBRSVi+tBdsxRwkeKo6KsUyPKwcrnM19JE=; h=Received:Received:From:To:Subject:Date:Message-ID:MIME-Version: Content-Type; b=DtFaPjsmuwDmnsFi7tnzL0wKjjFUg8Lu+ndCiRJuF54jD3ECk0+Id2USo1Skl1iRa hk7DMewkSFdXrI9/HzZXdhQe7vQ9K8X292uc5RzVPcbE/flU6wrNRQVCkKcX8qcven LzKuI+y5EfPTVCjaVdC4BtRij+L3r/d7+GTMAfu2pvSO4Uy8LG8mfQ+u596UIxzMnk rcR2lbBmXhMAFlOkIoRZyZ/4IAW99gNlTO2P9HQyUeWy23xPmVgIr35KQ+U7Gu+9MC 1bPAkbHV8lSTKKMIxlThppvYhXcZ/0UstIDXau9BpuI0ZKvO/RYoO41ZDhhBaVFAcj 2efuOu8HnErlQ== Received: from Owner ([IPv6:2601:141:0:bec5:79c0:c710:1e4e:5845]) by resomta-ch2-20v.sys.comcast.net with SMTP id MXsmc7TASEwWaMXsncnK3q; Thu, 29 Dec 2016 10:24:25 +0000 From: To: References: <159377c5fb0-275f-1de09@webprd-m63.mail.aol.com> <586427B8.9060907@posteo.de> In-Reply-To: <586427B8.9060907@posteo.de> Date: Thu, 29 Dec 2016 05:24:19 -0500 Message-ID: <01e101d261bd$b804a0f0$280de2d0$@comcast.net> MIME-Version: 1.0 X-Mailer: Microsoft Outlook 14.0 Thread-Index: AQIWQrK0fQav1pDJSDIoN12A7Tqs0AFKYDMTAadZDRGgf2C7sA== Content-Language: en-us X-CMAE-Envelope: MS4wfLtzzRsuvvp6BPlO5SRZdfqezK3g15VCCqI2tgs0J7DY11Qq0F35e5LKLaKww5LUIezuYVVdfjChDbxO8/hguLg7YuwlBreqcuClfqUI78rzKn1rnTl2 pXisvTtct3L9FDDh8vmJzWbAmwmlcIHyKYw= X-Scan-Signature: fc152e7304849b9a177649b85aea9f41 Subject: RE: VLF: New coil for 8270 Hz Content-Type: text/plain; charset="us-ascii" 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: O X-Status: X-Keywords: X-UID: 9985 Stefan, If you ever become interested in encapsulating an HV coil, I can send details for a straightforward process for low-cost/lightweight encapsulation that gives 10-year life in harsh outdoor environments with 10kV per inch across the problematic smooth surfaces. The dielectric is 450V/mil but the issue for lightweight long HV life in harsh outdoors is smooth interfaces between dissimilar materials, and this straightforward low cost process solves the problem. No special equipment needed. Decades of good field history with this process, no issues. 73, Jim AA5BW -----Original Message----- From: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] On Behalf Of DK7FC Sent: Wednesday, December 28, 2016 4:00 PM To: rsgb_lf_group@blacksheep.org Subject: Re: VLF: New coil for 8270 Hz Am 28.12.2016 19:00, schrieb jcraig@mun.ca: > PS Stefan's coil is very compact. 0,4 mm wire? Hope it can take the kV! Hi Joe, Yes, 0.4mm wire. The voltage is not the problem for the wire. But the tube is out of PVC and the length of the winding is about 0.3m. So it will be about 1kV/cm which could be problematic if the inner side of the tube becomes wet, inhomogeneous wet. This could cause strong local E field strength which leads to arcing on the surface. Arcing on the surface makes the surface conductive, a self accelerating process that can be repaired. This is the high risk of this construction! It has its advantages and disadvantages. It will handle 700 mA RF current, at least now in winter :-) But i should take care to keep it as dry as possible. We will see what happens. 73, Stefan