Return-Path: Received: (qmail 31426 invoked from network); 22 Oct 2002 09:32:59 -0000 Received: from warrior.services.quay.plus.net (212.159.14.227) by mailstore with SMTP; 22 Oct 2002 09:32:59 -0000 Received: (qmail 27078 invoked from network); 22 Oct 2002 09:32:19 -0000 Received: from post.thorcom.com (193.82.116.70) by warrior.services.quay.plus.net with SMTP; 22 Oct 2002 09:32:19 -0000 Received: from majordom by post.thorcom.com with local (Exim 4.10) id 183vN4-0006jb-00 for rsgb_lf_group-outgoing@blacksheep.org; Tue, 22 Oct 2002 10:30:42 +0100 Received: from [194.247.47.231] (helo=mailout.zetnet.co.uk ident=mail) by post.thorcom.com with esmtp (Exim 4.10) id 183vN3-0006jS-00 for rsgb_lf_group@blacksheep.org; Tue, 22 Oct 2002 10:30:41 +0100 Received: from irwell.zetnet.co.uk ([194.247.47.48] helo=zetnet.co.uk) by mailout.zetnet.co.uk with esmtp (Exim 3.35 #1 (Debian)) id 183vN3-0002ZT-00 for ; Tue, 22 Oct 2002 10:30:41 +0100 Received: from a7j7r2 (bts-0245.dialup.zetnet.co.uk [194.247.48.245]) by zetnet.co.uk (8.11.3/8.11.3/Debian 8.11.2-1) with SMTP id g9M9UZn13300 for ; Tue, 22 Oct 2002 10:30:36 +0100 Message-ID: <000801c279ad$b339adc0$f530f7c2@a7j7r2> From: "John Rabson" To: rsgb_lf_group@blacksheep.org References: <3DB0C203.A90691A6@verizon.net> Date: Tue, 22 Oct 2002 10:28:47 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Subject: LF: Re: Vacuum tubes on Motherboards... Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Status: No, hits=0.5 required=5.0tests=REFERENCES,SPAM_PHRASE_00_01,USER_AGENT_OEversion=2.42 Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group A few years ago, I was restoring an ancient Hallicrafters receiver and noticed the crisp quality of the audio compared with that of a 1960s transistorised communications receiver. I spoke to one of the experts at BT Labs, who suggested that the output transformer might have something to do with it. Also, the characteristics of a bipolar transistor audio output stage are _not_ identical to those of a pentode or beam tetrode. 73, John Rabson G3PAI