Return-Path: Received: (qmail 18777 invoked from network); 25 Jan 2002 10:46:01 -0000 Received: from unknown (HELO murphys-inbound.services.quay.plus.net) (212.159.14.225) by excalibur.plus.net with SMTP; 25 Jan 2002 10:46:01 -0000 Received: (qmail 5646 invoked from network); 25 Jan 2002 10:46:00 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys.services.quay.plus.net with SMTP; 25 Jan 2002 10:46:00 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 16U3pr-0007hk-00 for rsgb_lf_group-outgoing@blacksheep.org; Fri, 25 Jan 2002 10:43:55 +0000 Received: from mail004.syd.optusnet.com.au ([203.2.75.228]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 16U3pq-0007hf-00 for rsgb_lf_group@blacksheep.org; Fri, 25 Jan 2002 10:43:54 +0000 Received: from CO3043446A (c22590.sunsh1.vic.optusnet.com.au [203.164.134.8]) by mail004.syd.optusnet.com.au (8.11.1/8.11.1) with SMTP id g0PAh3R10845 for ; Fri, 25 Jan 2002 21:43:03 +1100 Message-ID: <003b01c1a58d$8da6dfa0$0886a4cb@CO3043446A> From: "Graeme Zimmer" To: rsgb_lf_group@blacksheep.org References: <5.1.0.14.0.20020124175326.02c734a0@gemini.herts.ac.uk> Subject: LF: Class D TX chips Date: Fri, 25 Jan 2002 21:46:32 +1100 MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit 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 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Hi, Those of you interested in digital transmitters might take a look at the new(ish) TPA3000D1 from TI. www.ti.com/sc/tpa3000d1 It's a class D audio amp capable of 17 Watts audio. It has a switching speed around 200 Khz. I figure it's a "good news" and "bad news" story. The good news is that it could possibly be used as a basis for a simple qrp VLF TX (I figure that the RC osc could be over-driven by an Xtal osc...) The bad news is that they are seriously proposing that these things be used in consumer equipment without any form of output filter.... ......................... Zim