X-GM-THRID: 1240520686410455976 X-Gmail-Labels: rsgb lf Delivered-To: daveyxm@gmail.com Received: by 10.78.172.10 with SMTP id u10cs185316hue; Thu, 28 Jun 2007 13:25:57 -0700 (PDT) Received: by 10.78.186.9 with SMTP id j9mr1155389huf.1183062357224; Thu, 28 Jun 2007 13:25:57 -0700 (PDT) Return-Path: Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mx.google.com with ESMTP id f7si1116199nfh.2007.06.28.13.25.50; Thu, 28 Jun 2007 13:25:57 -0700 (PDT) Received-SPF: neutral (google.com: 193.82.116.20 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1I40Vw-0004jn-KT for rs_out_1@blacksheep.org; Thu, 28 Jun 2007 21:22:52 +0100 Received: from [193.82.59.130] (helo=relay2.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1I40Vw-0004je-2H for rsgb_lf_group@blacksheep.org; Thu, 28 Jun 2007 21:22:52 +0100 Received: from pne-smtpout1-sn2.hy.skanova.net ([81.228.8.83]) by relay2.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1I40Vu-0006b4-TN for rsgb_lf_group@blacksheep.org; Thu, 28 Jun 2007 21:22:51 +0100 Received: from [127.0.0.1] (62.20.250.132) by pne-smtpout1-sn2.hy.skanova.net (7.2.075) (authenticated as u33233109) id 4656A9900083A16E for rsgb_lf_group@blacksheep.org; Thu, 28 Jun 2007 22:22:45 +0200 Message-ID: <4684189E.1070402@telia.com> Date: Thu, 28 Jun 2007 22:22:54 +0200 From: "Johan H. Bodin" User-Agent: Thunderbird 2.0.0.4 (Windows/20070604) MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <001701c7b9ab$5333d340$6d177ad5@w4o8m9> In-Reply-To: <001701c7b9ab$5333d340$6d177ad5@w4o8m9> X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: 500kHz class D TX design Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit 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 Status: O X-Status: X-Keywords: X-UID: 1101 Dear Jim, it would be very interesting to have a look at your TX design. Attached is a schematic of a push-pull class E amplifier. I have had good results with such a circuit at QRP levels on 80 and 160 meters with four paralleled junkbox 2N7000 on each side. With high enough tank Q, the transistors won't notice they are in a push-pull circuit since the high Q tank will keep the output current fairly sinusoidal and the two transistors will not fight each other's non-symmetrical drain waveforms. 73 Johan SM6LKM