Return-Path: X-Spam-DCC: paranoid 1233; 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=-2.2 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, HTML_50_60,HTML_MESSAGE 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 tATMclLZ031512 for ; Sun, 29 Nov 2015 23:38:47 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1a3AZM-0007dc-22 for rs_out_1@blacksheep.org; Sun, 29 Nov 2015 22:35:44 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1a3AZL-0007dT-LF for rsgb_lf_group@blacksheep.org; Sun, 29 Nov 2015 22:35:43 +0000 Received: from out1.ip02ir2.opaltelecom.net ([62.24.128.238]) by relay1.thorcom.net with esmtp (Exim 4.86) (envelope-from ) id 1a3AYR-0005G5-Gv for rsgb_lf_group@blacksheep.org; Sun, 29 Nov 2015 22:35:42 +0000 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: A2DXAQD2e1tWPKyNH1wNURkBAQEBDwEBAQGCPoIPhl+5P4YPAiWBMxABAQEBAQEBBgEBAQFAATSEPwEBAQECASNbCwsRBAEBASoCAiEiDAgGE4gZAwqnZXGLEw2EPwEBAQEBAQQBAQEBAQEBAQEBGYhkgWiBBoJTggaDHC+BFQWWV4tBk2CDIYdXOIQvcoVxAQEB X-IPAS-Result: A2DXAQD2e1tWPKyNH1wNURkBAQEBDwEBAQGCPoIPhl+5P4YPAiWBMxABAQEBAQEBBgEBAQFAATSEPwEBAQECASNbCwsRBAEBASoCAiEiDAgGE4gZAwqnZXGLEw2EPwEBAQEBAQQBAQEBAQEBAQEBGYhkgWiBBoJTggaDHC+BFQWWV4tBk2CDIYdXOIQvcoVxAQEB X-IronPort-AV: E=Sophos;i="5.20,360,1444690800"; d="scan'208,217";a="64426974" Received: from host-92-31-141-172.as13285.net (HELO [192.168.1.4]) ([92.31.141.172]) by out1.ip02ir2.opaltelecom.net with ESMTP; 29 Nov 2015 22:46:54 +0000 References: <56587F40.5070709@posteo.de> <87FFCE57-D2D7-4616-B5E8-B84CD819C685@talktalk.net> <5658E894.6090208@posteo.de> <82B8809C-36E5-4731-8A4B-002BD4465B12@talktalk.net> <5658EE97.2020107@posteo.de> From: Mal Hamilton X-Mailer: iPhone Mail (10B500) In-Reply-To: Message-Id: <902BA747-8D8F-477A-A2C8-E9103FDFCEDB@talktalk.net> Date: Sun, 29 Nov 2015 22:34:31 +0000 To: "rsgb_lf_group@blacksheep.org" Mime-Version: 1.0 (1.0) X-Scan-Signature: 40cd937fc1c5e6338b07d288cd09d087 Subject: Re: 3 phase (was LF: G3KEV) Content-Type: multipart/alternative; boundary=Apple-Mail-3067527C-49D3-458F-9D6A-4C38BF32AA0B 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 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 5451 --Apple-Mail-3067527C-49D3-458F-9D6A-4C38BF32AA0B Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Good discussion, I think 3 phase is available if requested insome parts of t= he UK G3kev Sent from my iPhone On 29 Nov 2015, at 09:42, Andy Talbot wrote: > If you use two transformers on a 3-phase supply, with the primary windings= in a SQRT(3) ratio, one connected in delta, and one in star across the supp= ly; equal value secondaries when rectified will give you 12X ripple instead o= f the 6X normal achieved though full wave 3-Ph rectification. >=20 > Unfortunately SQRT(3) is not rational (becuz Euclid sez so!) so any turns r= atios will be approximate, hence ripple will be degraded marginally >=20 > 'jnt >=20 >=20 >=20 >=20 > On 28 November 2015 at 18:20, mal hamilton wrote: >> Andy es Co >> 6 phase even better lower ripple. >> A car alternator is 3 phase, could easily be 6 >> g3kev >> =20 >> =20 >> =20 >> From: Andy Talbot >> Sent: Saturday, November 28, 2015 4:26 PM >> To: rsgb_lf_group@blacksheep.org >> Subject: Re: 3 phase (was LF: G3KEV) >> =20 >> What's wrong with that ? >> Sounds an excellent idea for a QRO transmitter. 300Hz ripple - much eas= ier to filter out. >> =20 >> My 137kHz Tx runs from rectified (single phase) mains - the isolation is p= rovided in the ferrite output transformer and FET drive pot-core >> =20 >> A school we once went around with long leads and an AVO identifying sock= ets to be found on all three of the phases. That was so that, using extensi= on leads, we could bring them all into the lab to get a three phase motor ru= nning. Such interesting things could be done in schools in the 1970's >> =20 >> Andy G4JNT >> =20 >> =20 >> On 28 November 2015 at 15:52, John Rabson wrote= : >>>=20 >>> In the early days of 73 kHz I believe a Luxembourg station built a trans= mitter which was powered off full-wave rectified three-phase mains without a= n isolating transformer. NOT the best way of doing things! >>>=20 >>> John F5VLF >=20 --Apple-Mail-3067527C-49D3-458F-9D6A-4C38BF32AA0B Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
Good discussion, I think 3 phase is av= ailable if requested insome parts of the UK
G3kev

Sent from= my iPhone

On 29 Nov 2015, at 09:42, Andy Talbot <andy.g4jnt@gmail.com> wrote:

If you use two transforme= rs on a 3-phase supply, with the primary windings in a SQRT(3) ratio, one co= nnected in delta, and one in star across the supply; equal value secondaries= when rectified will give you 12X ripple instead of the 6X normal achieved t= hough full wave 3-Ph rectification.

Unfortunately SQRT(3)= is not rational (becuz Euclid sez so!) so any turns ratios will be approxim= ate, hence ripple will be degraded marginally

'jnt<= /div>




On 28 November 2015 at 18:20, mal hami= lton <g3kevmal@talktalk.net> wrote:
Andy es Co
6 phase even better lower ripple.
A car alternator is 3 phase, could easily be 6
g3kev
 
 
 
 
What's wrong with that ?=20
Sounds an excellent idea for a QRO transmitter.   300Hz rippl= e -=20 much easier to filter out.
 
My 137kHz Tx runs from rectified (single phase) mains - the isolation i= s=20 provided in the ferrite output transformer and FET drive pot-core
 
A school we once went around with long leads and an AVO  identifyi= ng=20 sockets to be found on all three of the phases.  That was so that, usin= g=20 extension leads, we could bring them all into the lab to get a three phase m= otor=20 running.   Such interesting things could be done in schools in the= =20 1970's
 
Andy G4JNT
 
 
On 28 November 2015 at 15:52, John Rabson <= john.rabson07@gmail.com> wrote:

In the early days of 73 kHz I belie= ve a Luxembourg=20 station built a transmitter which was powered off full-wave rectified=20 three-phase mains without an isolating transformer. NOT the best way of do= ing=20 things!

John=20 F5VLF

= --Apple-Mail-3067527C-49D3-458F-9D6A-4C38BF32AA0B--