Return-Path: X-Spam-DCC: paranoid 1181; Body=3 Fuz1=3 Fuz2=3 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, HTML_MESSAGE,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 u2HEuPFi024300 for ; Thu, 17 Mar 2016 15:56:25 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1agZHc-0005Pr-Oh for rs_out_1@blacksheep.org; Thu, 17 Mar 2016 14:52:16 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1agZHc-0005Pi-Aj for rsgb_lf_group@blacksheep.org; Thu, 17 Mar 2016 14:52:16 +0000 Received: from nm35-vm9.bullet.mail.ir2.yahoo.com ([212.82.97.132]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.86) (envelope-from ) id 1agZHa-0008Dt-HS for rsgb_lf_group@blacksheep.org; Thu, 17 Mar 2016 14:52:15 +0000 X-DKIM-Result: Domain=yahoo.co.uk Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yahoo.co.uk; s=s2048; t=1458226333; bh=USXeCspQBETexCQLL+nPGMrP21ReYPjUTDHI5gCSljk=; h=Date:From:Reply-To:To:In-Reply-To:References:Subject:From:Subject; b=pUGN7B7wO4pt2edP92w+3UYSDWIs1WymIRZDjKJD8oJ5vCuyJxkEO0cjcc7OQlt3CiwwjYmEEcdnKHxwVA9xm2Q+v7chf+t7iN8INmpKlITs5rgIaJsMUeqFdNEVs2CBUQpX5DJKmdvp+XUDEN6hw+whWgq7TRnNNwo9oXL7UT/XiS4RD8DE7aj1asE+X90nhFPMoNZKGr0fLFIvmgEHp9TTzzYu8/JxykLJT8WTDrob/HAlA+vXOaPY2sFTS9NMiGg09M6mfB3+fhHkVXvLL09YTDZHksbAWfN+9LdvLf2FeWjhKZa3lf9zBH/Hf1sLjY2rTiIl7xHyhqUbhUvj+Q== Received: from [212.82.98.50] by nm35.bullet.mail.ir2.yahoo.com with NNFMP; 17 Mar 2016 14:52:13 -0000 Received: from [212.82.98.85] by tm3.bullet.mail.ir2.yahoo.com with NNFMP; 17 Mar 2016 14:52:13 -0000 Received: from [127.0.0.1] by omp1022.mail.ir2.yahoo.com with NNFMP; 17 Mar 2016 14:52:13 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 171177.95666.bm@omp1022.mail.ir2.yahoo.com X-YMail-OSG: jIHLNR8VM1noayHbnvciyCN.YE8J6dm3lgIQJzjBqlYhn6RVtc3Tz4QD1SJaXHh rty0xe3wU1_kTCYleTHf07N8GUPvQ0IUSHKuP7i5Mj4XVsHQh1pNIZ4NhCgAzrS1MObEjxj2zhL6 Zk9Oj0ZlKXHwThq84O3jUdXzlnIAa7mlChBAA7Cd6nsU9hmuITE1AWz_SE2p0IHPfXlxv0bhLaGV guPYqvy4dF2gvRnmDQ_YIFzPEcaZE2zIh6Wla14CAtxKM5rpm2mzYf7J7zwFd394ruD7cl3x8T2T VnucW6vatCXO_loSFTXxKqZ1MzX__8ai1pb2jdSXE2VUfVusx62AVJspMP8FGM.oxWbcc5giscXC Hrr2O4A8GLZJ9HlHjX667eY1gR2orY.bmVJ3qUdlsk2VZIvjlB3aof7WplKqxcOzwcZecL00OQTt BsW4.tewTjuX9YDYxz4uMiSYY69itIcziQPSihx4xBxBrFCen_Gh.IY1ra8Lpo0WmTzwrtNKNNLJ Kma6xeHxxQGGdXx.j8dccw_fLZe41Hv.Fg0xPjw9TdF0- Received: by 217.12.9.14; Thu, 17 Mar 2016 14:52:12 +0000 Date: Thu, 17 Mar 2016 14:52:12 +0000 (UTC) From: David Hine To: "rsgb_lf_group@blacksheep.org" Message-ID: <1494242924.559129.1458226332391.JavaMail.yahoo@mail.yahoo.com> In-Reply-To: References: MIME-Version: 1.0 X-Scan-Signature: c95b9a52470b89d54f2ef38e923e05cb Subject: Re: LF: 33 Hz QRM Content-Type: multipart/alternative; boundary="----=_Part_559126_1405115366.1458226332386" 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 Status: O X-Status: X-Keywords: X-UID: 7386 ------=_Part_559126_1405115366.1458226332386 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Hi, 16 2/3 Hz=C2=A0was used as it enables the older=C2=A0brush=C2=A0motors = to have much less losses than if they were run at 50 Hz -they would behave = much=C2=A0more as if DC was applied (easier to handle). However=C2=A050 Hz = is used on modern systems with electronic controllers on the trains to feed= the AC=C2=A0motors. The UK (southern Region) 3 rail DC=C2=A0is a 'throwbac= k' from the past (when DC was easy to generate and use)=C2=A0and=C2=A0 here= also modern=C2=A0stock uses electronic motor controllers to convert the tr= ack DC to suitable output for the modern AC=C2=A0motors. Eventually 16 Hz w= ill disappear and it will all be overhead HV 50 Hz except for a few DC=C2= =A0metros because of confined tunnels=C2=A0-even these now have electronic = AC=C2=A0on train motor control. So there=C2=A0are always many sources of 's= tray' signals near to railways. Hope this is of some help, Dave.=C2=A0=C2= =A0 From: Andy Talbot To: rsgb_lf_group@blacksheep.org=20 Sent: Thursday, 17 March 2016, 14:18 Subject: Re: LF: 33 Hz QRM =20 Is that to minimise skin loss in steel track ? UK Third rail is, of course, DC, and I once spent an idle moment calculatin= g the loss if 50Hz AC were to be used with magnetic iron conductors.=C2=A0 = I think I came to the conclusion a 1MW train could probably travel a few hu= ndred metres before it lost its power supply. andy=C2=A0 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 thir= d of 50 Hz) for traction. ... Can someone say whether my recollections are correct, please? 73 John F5VLF ------=_Part_559126_1405115366.1458226332386 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
Hi, <= /div>
16 2/3 Hz was used as it ena= bles the older brush motors to have much less losses than if they= were run at 50 Hz -they would behave much more as if DC was applied (= easier to handle). However 50 Hz is used on modern systems with electr= onic controllers on the trains to feed the AC motors. The UK (southern= Region) 3 rail DC is a 'throwback' from the past (when DC was easy to= generate and use) and  here also modern stock uses electron= ic motor controllers to convert the track DC to suitable output for the mod= ern AC motors. Eventually 16 Hz will disappear and it will all be over= head HV 50 Hz except for a few DC metros because of confined tunnels&n= bsp;-even these now have electronic AC on train motor control. So ther= e are always many sources of 'stray' signals near to railways. Hope th= is is of some help, Dave. 
 

From: An= dy Talbot <andy.g4jnt@gmail.com>
To: rsgb_lf_group@blacksheep.org
Sent: Thursday, 17 March 2016, 14:18
Subject: Re: LF: 33 Hz QRM
=

Is that to minimise skin loss in steel track ?

UK Third rail is, of course, DC, and I once spent an idle mo= ment calculating the loss if 50Hz AC were to be used with magnetic iron con= ductors.  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 &= lt;jhbodin@tele2.se> wrote:
Railway QRG is 16 2/3 Hz in Swe= den too.

73 de Johan SM6LKM

John Rabson wrote:
I seem to recall that some railway systems use at about 16 2/3 Hz (one thir= d of 50 Hz) for traction.
...
Can someone say whether my recollections are correct, please?

73 John F5VLF




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