Return-Path: X-Spam-DCC: paranoid 1169; 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=-2.6 required=5.0 tests=BAYES_00 autolearn=ham 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 s679w6Wo032011 for ; Mon, 7 Jul 2014 11:58:07 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1X45cr-0000st-GE for rs_out_1@blacksheep.org; Mon, 07 Jul 2014 10:54:21 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1X45cr-0000sk-3p for rsgb_lf_group@blacksheep.org; Mon, 07 Jul 2014 10:54:21 +0100 Received: from mail-we0-f175.google.com ([74.125.82.175]) by relay1.thorcom.net with esmtps (TLSv1:RC4-SHA:128) (Exim 4.82) (envelope-from ) id 1X45cp-0007cR-84 for rsgb_lf_group@blacksheep.org; Mon, 07 Jul 2014 10:54:19 +0100 Received: by mail-we0-f175.google.com with SMTP id k48so4009209wev.34 for ; Mon, 07 Jul 2014 02:54:13 -0700 (PDT) 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=subject:mime-version:content-type:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=yfo8RR3f6PVcZIVlqHKKuFut/kP8ZTa63AeDUcyUO+E=; b=qVohdtH3aTr2Vzsfq300h+FKNEANCgErzTuzzwaoSFKdRWT7rJLvqRqy3d4JYbK3VW lENqQlQW3qtzASW3lAKDeJvJsy+gdsRfqdu1v+RreL7SfLPsjRtzDTcPoBqJ6faV38Bq IUPh9s3B+4dpYdIvYUPmQxEoi3W8dyV7ytxIw0W3JYsXstH635iIi1OQpMPHCqFumPhs GeORUoCrqaeeoQOmoFvOZSMBb2Y1WK17GCEnmG5syDD4D0tViQRfN5UhnqPmrNkFJVhQ A0985t4xMQI3BlqkiORmsZeFz4SARRzgf9SMg4cDEBDoh/n/Fhr75SVIPPqpdsJ97g6T O/QA== X-Received: by 10.194.221.6 with SMTP id qa6mr30544783wjc.39.1404726852461; Mon, 07 Jul 2014 02:54:12 -0700 (PDT) Received: from [192.168.1.101] ([217.67.155.178]) by mx.google.com with ESMTPSA id m3sm88327209wjr.49.2014.07.07.02.54.11 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 07 Jul 2014 02:54:11 -0700 (PDT) Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.2\)) From: John Rabson X-Priority: 3 In-Reply-To: <9FE61D98573D45E08A39735EF283914F@gmc.net> Date: Mon, 7 Jul 2014 11:54:24 +0200 Cc: p.maly@gmc.net Message-Id: <000D275C-30FB-4EF0-91B5-05C2CD050A90@gmail.com> References: <9FE61D98573D45E08A39735EF283914F@gmc.net> To: rsgb_lf_group@blacksheep.org X-Mailer: Apple Mail (2.1878.2) X-Scan-Signature: c0336009bd9bab526ca27d297ea7579a Subject: Re: LF: Pure off-topic: old tubes Content-Type: text/plain; charset=windows-1252 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 Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by paranoid.lipkowski.org id s679w6Wo032011 Status: O X-Status: X-Keywords: X-UID: 22 Petr, In the 1960s, STC (Standard Telephones and Cables) was part of ITT (International Telephone and Telegraph Corporation) so the two bottles are probably electrically similar. I never worked in Valve Division, but if I recall correctly the initial figure 4 indicates a tetrode or a beam tetrode. Figure 5 was used to indicate either a beam tetrode or a pentode. The 55 probably does refer to the maximum permitted anode dissipation in Watts. One or other B may refer to British manufacture or base but I am not sure. Before applying power to the heaters, you do need to confirm the voltage required. I believe some of these devices were designed for substantially less than the traditional 6.3V. I hope this helps. 73: John F5VLF On 07 Jul 2014, at 09:20, Petr Maly wrote:Wake up > Hello all > > I apology for the off-topic. However I know that this group is attended by very experienced gents, mainly from the UK. > I found these two tubes in the junk, see the attachment. I spent quite a while to search the whole Internet for some specs, in vain. > They are very similar to QB3/300, or TESLA’s RE125, same size, same socket. The only visible difference is the shape and material of the anode. > I think the number 55 in the designation could possibly be the anode dissipation. > The labels are: > STC 4B/55 > ITT 4B/55/B > By some lucky chance does anybody have any information about them? > > Thanks, 73, Petr, OK1FIG > > > >