Return-Path: X-Spam-DCC: paranoid 1102; 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=-2.4 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, 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 u2V9bbvG008862 for ; Thu, 31 Mar 2016 11:37:37 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1alYyX-0000aB-3C for rs_out_1@blacksheep.org; Thu, 31 Mar 2016 10:33:13 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1alYyW-0000a2-IS for rsgb_lf_group@blacksheep.org; Thu, 31 Mar 2016 10:33:12 +0100 Received: from mail-wm0-x22d.google.com ([2a00:1450:400c:c09::22d]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.86) (envelope-from ) id 1alYyU-0005nO-Py for rsgb_lf_group@blacksheep.org; Thu, 31 Mar 2016 10:33:11 +0100 Received: by mail-wm0-x22d.google.com with SMTP id 191so119332789wmq.0 for ; Thu, 31 Mar 2016 02:33:10 -0700 (PDT) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:subject:from:in-reply-to:date :content-transfer-encoding:message-id:references:to; bh=gQmVGy85jGl2vc1m9s8XD3t5CjYXnqqvUl/0hnekLoA=; b=h7hfOlMH3ihaTokp8cjTHy4MopOnCgdqM0RfbB4bHbxl4DKoyiTh3mxdZ4JfZ7gSqO o07ZULXiqAckO1hcNuQTZKbdL0pEX0W4ROtK3PpEA4VCoTBRv9CPH8LikFFc7d8HyGU/ /UW5bGoY/pCfpFtX9aZ03JBYZ2JZluhTjiBlYPZabWwEVoMoJ+iC/q9jNXPopMxDJUQT BynAVQZ/YKB2PpBlV9Rmfg66wU8ttnbYvwbLTWvIUg6jNQZJAFLZ8eoYnCIEsqmD52Sr fa0A9ACqFwesh1t7H+bZkXA5XPQsElajyUUMRatHPQOaWltK1fByCSsnmDNlqAYTPRnu FrXQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:subject:from:in-reply-to:date :content-transfer-encoding:message-id:references:to; bh=gQmVGy85jGl2vc1m9s8XD3t5CjYXnqqvUl/0hnekLoA=; b=D6HjBDxfvnkrq5ePNI/mFpEpojHd9lYFm+tEVJzxjbxj3O9x12FCyxj0LQg+JvBq0b q4g/e/zd2laSXo/MD8Fr+Ffv0yJ/VySy4RZlAJ/tEnBnh1mEkzMyHsnovGYMAVnQ6qbb 5lZ44Bb6ga7XT844qXEt/2X2qGtyjl1L24Xrkd744JUZlQkjdHD6ESrhWoHLZ8CERnZM ZnZsi7yOdUbAgRThXzPNgpijcR4ZHNBNK4bS1fu2eKg9MJ9jhnXVCxiaMUlJoaJvKU9u poUuOMFjBrOhw3bLhxJLtAmCha4oNiWMOrKtrTAEcwb19DLTtlmMJPLqexMDnk/Cg2ms 534w== X-Gm-Message-State: AD7BkJKaIHyG/fzMxthCMBi4YyJUkshTgG3g0oZu7g5fjfqTk6SCfZJn6oD5EWqfMhQvcQ== X-Received: by 10.194.103.72 with SMTP id fu8mr15049102wjb.70.1459416789287; Thu, 31 Mar 2016 02:33:09 -0700 (PDT) Received: from [192.168.1.101] ([82.98.23.94]) by smtp.gmail.com with ESMTPSA id e19sm23932973wmd.1.2016.03.31.02.33.06 for (version=TLSv1/SSLv3 cipher=OTHER); Thu, 31 Mar 2016 02:33:08 -0700 (PDT) Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) From: John Rabson In-Reply-To: <56FA2A98.6030005@tele2.se> Date: Thu, 31 Mar 2016 11:33:05 +0200 Message-Id: <13CD7C6C-638A-46C8-AA19-4875D228443C@gmail.com> References: <8D34C58CF884ECC-1ECC-700FAE@webmail-vd008.sysops.aol.com> <8D34CA56489C6DF-2124-1A7BBA@webmail-vm017.sysops.aol.com> <1D7A91E7-DC1B-4641-95BE-FC096D8155E4@gmail.com> <56EAAF40.20204@tele2.se> <56FA2A98.6030005@tele2.se> To: rsgb_lf_group@blacksheep.org X-Mailer: Apple Mail (2.3124) X-Scan-Signature: 1c38f63d01970a2bf149f660c9cb2a37 Content-Type: text/plain; charset=us-ascii Subject: Re: LF: 33 Hz QRM 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 Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by paranoid.lipkowski.org id u2V9bbvG008862 Status: O X-Status: X-Keywords: X-UID: 7528 Johan, Many thanks for the reference. I now understand much better how these things are arranged. 73 John F5VLF > On 29 Mar 2016, at 09:11, Johan Bodin wrote: > > That problem can be solved by using a return line and booster transformers that minimises current leakage into surrounding earth: > > https://library.e.abb.com/public/f1200714de5086c585257d7300287357/1LFI2026%20special%20power%20transformers%20for%20railway%20-%20brochure%20EN.pdf > > 73 de > Johan SM6LKM > > Den 2016-03-17 kl. 15:18, skrev Andy Talbot: >> Is that to minimise skin loss in steel track ? >> >> UK Third rail is, of course, DC, and I once spent an idle moment calculating the loss if 50Hz AC were to be used with magnetic iron conductors. I think I came to the conclusion a 1MW train could probably travel a few hundred metres before it lost its power supply. >> >> andy G4JNT >> >> On 17 March 2016 at 13:21, Johan Bodin wrote: >> Railway QRG is 16 2/3 Hz in Sweden too. >> >> 73 de Johan SM6LKM >> >> John Rabson wrote: >> I seem to recall that some railway systems use at about 16 2/3 Hz (one third of 50 Hz) for traction. >> ... >> Can someone say whether my recollections are correct, please? >> >> 73 John F5VLF >> >> > john.rabson07@gmail.com Researching history of RABSON, BLACKSHAW, GAUNTLETT, VERLANDER and ROBSONNE