Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dk04.r1000.mx.aol.com (Internet Inbound) with ESMTP id 44F5D380000AC; Tue, 18 Dec 2012 19:49:21 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Tl7pZ-000850-5K for rs_out_1@blacksheep.org; Wed, 19 Dec 2012 00:48:17 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Tl7pY-00084r-JZ for rsgb_lf_group@blacksheep.org; Wed, 19 Dec 2012 00:48:16 +0000 Received: from mail-ia0-f176.google.com ([209.85.210.176]) by relay1.thorcom.net with esmtps (TLSv1:RC4-SHA:128) (Exim 4.77) (envelope-from ) id 1Tl7pW-0005sf-Qq for rsgb_lf_group@blacksheep.org; Wed, 19 Dec 2012 00:48:15 +0000 Received: by mail-ia0-f176.google.com with SMTP id y26so1187654iab.35 for ; Tue, 18 Dec 2012 16:47:52 -0800 (PST) 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:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=YpSXiGfgmTffNVCLkFSNJpXEFUC9ZmgLPTX+LSjfVMY=; b=AxSnwMHNgAHrLBl4QMPziZwoEkMBhO5O4M6Q564jh/dKyXaguLlzT3r75ioyaYuSaa tBHWBFXn57bOXeO6KnJTlJq3E+RMwocCchBArFevljQ3KYqmHiK4GlHFMN+PZ4ivgayB 6lMyd+fGkBm+VZqkXi3zIdbiD4w9wQ9vVH+JlDJNq412VW1P/iYUXAq0UoSSZctoaQgp 06I05xjWnFPpxGt3syIRoyh2pkBqNY1mCrn5T1+YhMEJYJ0pV+/J2p3y/BJTU5wSssrP sjMmmSE8I4eiRHT/t6RdDE/eWZ3eAHvxcoLkYTbpKS1WtoBuIHovsizroLdWHaGgq/gd GS8A== MIME-Version: 1.0 Received: by 10.50.57.232 with SMTP id l8mr5467223igq.54.1355878072683; Tue, 18 Dec 2012 16:47:52 -0800 (PST) Received: by 10.231.157.74 with HTTP; Tue, 18 Dec 2012 16:47:52 -0800 (PST) In-Reply-To: <9E879884664540C8BC7A08377EAFC51C@AGB> References: <20121218092921.Horde.h2yZX_rSz0VQ0BtRPVIC2uA@posti.anvianet.fi> <20121218100332.Horde.2ASBc_rSz0VQ0CNU8mNkBhA@posti.anvianet.fi> <20121218152622.Horde.XfcUIerSz0VQ0G7_VqKUnlA@posti.anvianet.fi> <83EEBFC65ED94B0880138E0637A84E24@AGB> <9E879884664540C8BC7A08377EAFC51C@AGB> Date: Wed, 19 Dec 2012 11:47:52 +1100 Message-ID: From: Dimitrios Tsifakis To: rsgb_lf_group@blacksheep.org X-Spam-Score: -0.7 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: That is not the final schematic, this is one I drew as a starting point and there have been many changes (including a cathode resistor to provide some of the bias and a resistor with a few turns on it on the plate for avoiding parasitic oscillations). It's not quite class-c, it's somewhere between class-c and class-b by the way. The VR valves were not used when I configured this for AM, but I am only using CW now, so I thought the regulated screen voltage is not a problem... Need to revisit that I guess... [...] Content analysis details: (-0.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [209.85.210.176 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (dtsifakis[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: 66d07794ca19cd68f7d6cc289cd4ac18 Subject: Re: LF: Better picture of the 807 based 500kHz TX Content-Type: text/plain; charset=ISO-8859-1 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=none autolearn=no version=2.63 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-aol-global-disposition: G X-AOL-SCOLL-AUTHENTICATION: mtain-dk04.r1000.mx.aol.com ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1db40850d10f116073 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none That is not the final schematic, this is one I drew as a starting point and there have been many changes (including a cathode resistor to provide some of the bias and a resistor with a few turns on it on the plate for avoiding parasitic oscillations). It's not quite class-c, it's somewhere between class-c and class-b by the way. The VR valves were not used when I configured this for AM, but I am only using CW now, so I thought the regulated screen voltage is not a problem... Need to revisit that I guess... 73, D. 2012/12/19 Graham : > lol well that config is for linear service , you should have the > screen fed via something like 6.8K from the plate supply , with a > 0.1 uF decoupling cap , no regulation for class C as the screen voltage > will vary as the anode amps / secondary emission changes [ negative > resistance type of thing] , you need a 100 ohm 2 watt resistor , > shorted with a over wound 8 turn 10 mm id coil directly to the anode > as acp , would normally have 50/100 ohms in series with the cathode > as auto bias , should the drive fail, or IA = inf very quickly ... > starts off with orange anodes by the wire supports , then yellow , > then sparks inside , then white anodes , then glass shatters / melts > = game over , with cathode keying , looking at a big gap cw key ! > > Happy days : ) > > > G.. > > -------------------------------------------------- > From: "Dimitrios Tsifakis" > Sent: Tuesday, December 18, 2012 11:46 PM > > To: > Subject: Re: LF: Better picture of the 807 based 500kHz TX > >> 2012/12/19 Graham : >>> >>> Why the stabilised screen supply ? >>> G.. >> >> >> It's embarassing. I like the glow of VR tubes! :-) >> >> 73, Dimitris VK1SV >> >