Return-Path: Received: (qmail 4415 invoked from network); 1 Feb 2001 08:01:54 -0000 Received: from unknown (HELO warrior-inbound.servers.plus.net) (212.159.14.227) by 10.226.25.101 with SMTP; 1 Feb 2001 08:01:54 -0000 Received: (qmail 4705 invoked from network); 1 Feb 2001 08:05:31 -0000 Content-Transfer-Encoding: 8bit Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by warrior with SMTP; 1 Feb 2001 08:05:31 -0000 X-MSMail-Priority: Normal Received: from majordom by post.thorcom.com with local (Exim 3.16 #1) id 14OEc3-0001RC-00 for rsgb_lf_group-outgoing@blacksheep.org; Thu, 01 Feb 2001 07:57:03 +0000 Received: from tlvsca.vim.tlt.alcatel.it ([194.243.74.245]) by post.thorcom.com with esmtp (Exim 3.16 #1) id 14OEbz-0001R7-00 for rsgb_lf_group@blacksheep.org; Thu, 01 Feb 2001 07:57:00 +0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from tlvk7v (tlvk7v.vim.tlt.alcatel.it [151.98.40.9]) by tlvsca.vim.tlt.alcatel.it (8.9.3+Sun/8.9.3) with SMTP id IAA03505 for ; Thu, 1 Feb 2001 08:55:14 +0100 (MET) Date: Thu, 1 Feb 2001 08:21:30 +0100 From: "Claudio Girardi" Subject: LF: EHT transformer cores To: rsgb_lf_group@blacksheep.org X-Mailer: Z-Mail Pro 6.2, NetManage Inc. [ZM62_16H] X-Priority: 3 Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=ISO-8859-1; format=flowed Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Hi Jim and all the LF group, I've actually used some core of TV EHT transformer for the output transformer of amplifiers in the 300-500W range and they performed weel indeed; one of these had the two halves glued together so there was no way to modify the gap, while in the others I removed only one of the thin plastic spacers. I didn't try removing both since the inductance I obtained was enough 8-). One of the cores was marked with a code like 3C...something that resembled a ferrite grade code, but I don't remember exactly all the numbers. Anyway, as Andy said, there is no substitute for trying... 73 and GL de Claudio, IN3OTD -- http://www.qsl.net/in3otd > The ferrite cores used in TV EHT line output transformers use > similar materials to the SMPSU transformers - they operate at a > lower frequency, so some might be more lossy, you will just have > to try. The type with a metal clip are handy to wind cables round for > RFI supression, but they are a slightly awkward shape for making a > transformer with. Make sure you remove any thin plastic film > spacers from the joining surfaces before using; the 'air gap' is good > for an energy storage inductor, but not a transformer.