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=HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_MED,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 X-Spam-DCC: EATSERVER: mailn 1166; Body=2 Fuz1=2 Fuz2=2 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 uBSHG4vi029000 for ; Wed, 28 Dec 2016 18:16:07 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1cMHjm-00086r-BL for rs_out_1@blacksheep.org; Wed, 28 Dec 2016 17:10:02 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1cMHjl-00086d-Gi for rsgb_lf_group@blacksheep.org; Wed, 28 Dec 2016 17:10:01 +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 1cMHji-0004Kk-O0 for rsgb_lf_group@blacksheep.org; Wed, 28 Dec 2016 17:10:00 +0000 Received: from submission (posteo.de [89.146.220.130]) by mout02.posteo.de (Postfix) with ESMTPS id CCA9F2102B for ; Wed, 28 Dec 2016 18:09:54 +0100 (CET) Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 3tpfNy4g3pz104L for ; Wed, 28 Dec 2016 18:09:54 +0100 (CET) Message-ID: <5863F1E2.70000@posteo.de> Date: Wed, 28 Dec 2016 18:09:54 +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: <5860C842.90809@abelian.org> <159461afc0c-505-23d0a@webprd-a16.mail.aol.com> In-Reply-To: X-Scan-Signature: 0b2d339ae1d48966556dfb6ad64e2bce Subject: VLF: New coil for 8270 Hz Content-Type: text/plain; charset=UTF-8; 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: 9975 Hi VLF, Today was (is) a good day. For the first time i tested the new VLF coil on the antenna. The coil is built for 8270 Hz. The DC resistance is just 230 Ohm! It is intended to run 700 mA. A 3 layer coil, each layer has 30 turns, overlapping the last layer with 20 turns. So far it has 70 layers. And the diameter is 0.25 m. So thats super compact and robust. About 50 hours of winding though! In a first test i measured 230 mA RF current and the power supply showed 0.94 A and 24.5 V. So that's just 23W including PA losses. Not bad at all. However the resonance frequency is 8.607 kHz, and that's why the coil is back in the shack now, waiting for another 3 layers. But soon i will be there... https://dl.dropboxusercontent.com/u/19882028/VLF/20161228_151854.jpg 73, Stefan