Return-Path: X-Spam-DCC: paranoid 1181; 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=-2.0 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_30_40,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 u2HFfXuF024480 for ; Thu, 17 Mar 2016 16:41:33 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1agZzg-0005g3-49 for rs_out_1@blacksheep.org; Thu, 17 Mar 2016 15:37:48 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1agZzf-0005fu-P8 for rsgb_lf_group@blacksheep.org; Thu, 17 Mar 2016 15:37:47 +0000 Received: from mail-vk0-x22a.google.com ([2607:f8b0:400c:c05::22a]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.86) (envelope-from ) id 1agZzd-0008Pm-S4 for rsgb_lf_group@blacksheep.org; Thu, 17 Mar 2016 15:37:46 +0000 Received: by mail-vk0-x22a.google.com with SMTP id e6so106849111vkh.2 for ; Thu, 17 Mar 2016 08:37:45 -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:sender:in-reply-to:references:date:message-id:subject :from:to; bh=m+kwd3SQXRqpqMF/lbowzh3lyAvRTKZpT+QgfEwzBgg=; b=bawVgXijyubEnBscLkLnEIV4+LgCkdO3ZE00HFzH1qAX7L3kOMn4lIL0au0usSVuBT Zf1SPC3YcbcdL6v8Luxl0H1XZ8gqyg4WWvSnzmO6BjfgiOs/VUOf+MwQOc5KT30DRX6Y /ItZElc7BHU6Dqoy6SOw1uu3B51/WMQfpAWwGI2ViuSG7dKhKmRbpKi7lB2JeuMqd62A Tsmg7B+gQMFOTKNym+5+I7CQoXnOPmDS4a8poQzonXgjEBnLR0YD84LbdP2I+FQl0fbF zPoRlb9mQA6KFnm1C5aNdMBMLivL/FO6FcyMm4xZ6m47QEpik2QYWarQLls/XXscS0YE 6DFg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:sender:in-reply-to:references:date :message-id:subject:from:to; bh=m+kwd3SQXRqpqMF/lbowzh3lyAvRTKZpT+QgfEwzBgg=; b=Nqkq5z4Dh7UBo2EwDLmIojjHtQ5yG1X8sTHmdXxknCmKLo53IHS5swNtUDFDChL0wy rqSYogsLB+sUc1s5bth4bvI3QX+k1liA6ddBo2g9vAdkACTvKxt3Nj8H0if7Qzg9fNG5 udn/2avuXxDwD//mIl1SDGyLE74MpgmlWGH+MH5ZO8Nrqh4EihFslUdKLCq0r8XWYvZT WmQDPRflTAqMkrS2lMzMvEQYirAyf90IXIILNsxF0bAgL3NQl0w95ctKeBJi8MRElPQc GY2wQ+jpcqTMcOHjW2J0Ft0DqeTtlApQhjJwqWWGAbbC/tMjF646uit/MIsFZzMyou4s MlFw== X-Gm-Message-State: AD7BkJLVdZnB85c6welGHaaO81JY2wY/Q3QJfPnUqhkgxBRrYBhdDMnIKBOu/ZM+AGg+TggLz8ed/VupXcgsuQ== MIME-Version: 1.0 X-Received: by 10.31.192.78 with SMTP id q75mr12241879vkf.96.1458229064157; Thu, 17 Mar 2016 08:37:44 -0700 (PDT) Received: by 10.159.36.108 with HTTP; Thu, 17 Mar 2016 08:37:44 -0700 (PDT) In-Reply-To: <20160317145911.Horde.1H5cYcrPocF3dL5aHYIO7w3@posti.anvianet.fi> 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> <20160317145911.Horde.1H5cYcrPocF3dL5aHYIO7w3@posti.anvianet.fi> Date: Thu, 17 Mar 2016 16:37:44 +0100 X-Google-Sender-Auth: StsOapcerN1oK7JlH7mIO-S9htI Message-ID: From: PA7EY To: rsgb_lf_group@blacksheep.org X-Scan-Signature: e51657317b06d9cbe905ec682fad6602 Subject: Re: LF: 33 Hz QRM Content-Type: multipart/alternative; boundary=001a1143a0d05f03e4052e4069f3 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: 7388 --001a1143a0d05f03e4052e4069f3 Content-Type: text/plain; charset=UTF-8 I suppose 16 2/3 is correct (16 1/3 x 3 = 49), according to my information, they actually use 16.7 in some places these days. 73 Ulrich PA7EY 2016-03-17 15:59 GMT+01:00 : > Hello John, Johan, LF > > 16 2/3 Hz should probably be 16 1/3 Hz, one third of 50 Hz as John pointed > out. > > > Here in OH-land we use 50 Hz for the railways but during my EE studies, > the SM-land railway QRG was also mentioned for two reasons (hope I remember > this right now, it was about 25 years ago...): > > - A lower frequency was selected to minimize the voltage drop caused by > the series inductance formed by the long overhead lines supplying the > locomotive. > > - Initially 16 1/3 Hz was generated in rotary converters, for example a > 6-pole 50 Hz motor would drive a two pole generator which gives the > required step-down. Rotary converters need maintenance and so this system > was later replaced by non-mechanical devices such as cyclo-converters or > other early ways of electronic frequency converters that supposedly require > less maintenance. In fact, I think this was the main reason for bringing > up this subject in school. > > > BR > > Paul-Henrik, OH1LSQ > > > > Quoting 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 >>>> >>>> >>> >>> > > > --001a1143a0d05f03e4052e4069f3 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
I suppose 16 2/3 is corre= ct (16 1/3 x 3 =3D 49), according to my information, they actually use 16.7= in some places these days.

73 Ulrich PA7EY

2016-03-17 15:59 GMT+01:00 <phl@n= etikka.fi>:
Hello John, Joh= an, LF

16 2/3 Hz should probably be 16 1/3 Hz, one third of 50 Hz as John pointed = out.


Here in OH-land we use 50 Hz for the railways but during my EE studies, the= SM-land railway QRG was also mentioned for two reasons (hope I remember th= is right now, it was about 25 years ago...):

- A lower frequency was selected to minimize the voltage drop caused by the= series inductance formed by the long overhead lines supplying the locomoti= ve.

- Initially 16 1/3 Hz was generated in rotary converters, for example a 6-p= ole 50 Hz motor would drive a two pole generator which gives the required s= tep-down. Rotary converters need maintenance and so this system was later r= eplaced by non-mechanical devices such as cyclo-converters or other early w= ays of electronic frequency converters that supposedly require less mainten= ance. In fact,=C2=A0 I think this was the main reason for bringing up this = subject in school.


BR

Paul-Henrik, OH1LSQ



Quoting Andy Talbot <andy.g4jnt@gmail.com>:

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.=C2=A0 I think I came to the conclusion a 1MW train could probab= ly
travel a few hundred metres before it lost its power supply.

andy=C2=A0 G4JNT

On 17 March 2016 at 13:21, Johan Bodin <jhbodin@tele2.se> 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







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