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 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 tAEKcnMW002230 for ; Sat, 14 Nov 2015 21:38:49 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ZxhYe-0007OX-F1 for rs_out_1@blacksheep.org; Sat, 14 Nov 2015 20:36:24 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ZxhYe-0007OG-69 for rsgb_lf_group@blacksheep.org; Sat, 14 Nov 2015 20:36:24 +0000 Received: from out1.ip01ir2.opaltelecom.net ([62.24.128.237]) by relay1.thorcom.net with esmtp (Exim 4.86) (envelope-from ) id 1ZxhXa-0006fZ-2j for rsgb_lf_group@blacksheep.org; Sat, 14 Nov 2015 20:36:23 +0000 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: A2C8AQAfmkdWPKyNH1wNURkBAQIPAQEBAYRNhl25YoYQAoF4AQEBAQEBBwEBAQFAAYR0AQEBAgE6RAsLPwdDAxEGE4gmpW6RDAEBAQEBBQEBAQEBAQEBG4hkgm6ENBqDVoEVBYdBBYcHh3uNLJxAhGdyhAGBSgEBAQ X-IPAS-Result: A2C8AQAfmkdWPKyNH1wNURkBAQIPAQEBAYRNhl25YoYQAoF4AQEBAQEBBwEBAQFAAYR0AQEBAgE6RAsLPwdDAxEGE4gmpW6RDAEBAQEBBQEBAQEBAQEBG4hkgm6ENBqDVoEVBYdBBYcHh3uNLJxAhGdyhAGBSgEBAQ X-IronPort-AV: E=Sophos;i="5.20,294,1444690800"; d="scan'208";a="804805484" Received: from host-92-31-141-172.as13285.net (HELO [192.168.1.4]) ([92.31.141.172]) by out1.ip01ir2.opaltelecom.net with ESMTP; 14 Nov 2015 20:35:02 +0000 References: <4510637253.20151114190626@chriswilson.tv> <825751561.20151114200051@chriswilson.tv> From: Mal Hamilton X-Mailer: iPhone Mail (10B500) In-Reply-To: <825751561.20151114200051@chriswilson.tv> Message-Id: Date: Sat, 14 Nov 2015 20:35:01 +0000 To: "rsgb_lf_group@blacksheep.org" Mime-Version: 1.0 (1.0) X-Scan-Signature: d7907c3bf895ca41e0bedc3fa074f0d4 Subject: Re: Re[2]: LF: Valve LF amps and tank coil size / voltage rating? Content-Type: text/plain; charset=us-ascii 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: 5078 Beware It sounds like an Electric chair you are Building ------one zap and u are gone!!! G3kev Sent from my iPhone On 14 Nov 2015, at 20:00, Chris Wilson wrote: > Hello Andy, > > Saturday, November 14, 2015 > > > OK, but what about wire breakdown voltages? In all the big air cored > LF tanks I have seen the windings are well spaced on ceramic, or > Paxolin type grooved formers, how do I know a close wound toroidal > coil won't break down? > > > I have built a few HV supplies using decent industrial quality iron > cored transformers, the biggest is 5kV at 1.5 Amps, which can also be > fed from a 40 Amp Variac, to drop the primary down. I use that in my > workshop for running a glue drying machine. > > I was also gifted some NOS ceramic triodes, some US, some Russian, and > would consider having a bash at a valved LF amp, just "because" :) I > have to say my limited experience of ceramic triodes has shown no > unreliability, in fact a zero failure rate so long as they are > gettered before use, if they have lain dormant for years. > > I do have a reasonable collection of failed FET's though :) In > fairness user error was the demise of most of them. > > > Thanks Andy. > > >> I'll say it againV = 4.44.F.N.A.B (all SI units) > > >> THAT is how you size ferrite cores. It tells you more or less >> everything you need to know to make ferrite transformers. Keep B to >> less than 0.1 at these frequencies > > >> But.. why would you want to use valves? >> Expensive, unreliable, high voltages... > > >> 'jnt > > > > > > > > > -- > Best regards, > Chris 2E0ILY mailto:chris@chriswilson.tv > >