Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dd04.r1000.mx.aol.com (Internet Inbound) with ESMTP id 92203380000B3; Fri, 13 Jan 2012 07:28:48 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1RlgEU-0002D3-UM for rs_out_1@blacksheep.org; Fri, 13 Jan 2012 12:27:46 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1RlgEU-0002Cu-JN for rsgb_lf_group@blacksheep.org; Fri, 13 Jan 2012 12:27:46 +0000 Received: from nina.ucs.mun.ca ([134.153.232.76]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1RlgER-0003hj-SR for rsgb_lf_group@blacksheep.org; Fri, 13 Jan 2012 12:27:46 +0000 Received: from plato.ucs.mun.ca (plato.ucs.mun.ca [134.153.232.153]) by nina.ucs.mun.ca (8.13.1/8.13.1) with ESMTP id q0DCRa50032436 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Fri, 13 Jan 2012 08:57:36 -0330 Date: Fri, 13 Jan 2012 08:57:36 -0330 (NST) From: jcraig@mun.ca X-X-Sender: jcraig@plato.ucs.mun.ca To: rsgb_lf_group@blacksheep.org In-Reply-To: <4F101646.3040400@iup.uni-heidelberg.de> Message-ID: References: <4F101646.3040400@iup.uni-heidelberg.de> MIME-Version: 1.0 X-MUN-Disclaimer: http://www.mun.ca/cc/policies/elect_communications_disclaimer_2011.php X-Spam-Score: 0.6 (/) X-Spam-Report: autolearn=disabled,NO_REAL_NAME=0.55 Subject: Re: LF: TA condx last night Content-Type: TEXT/PLAIN; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.3 required=5.0 tests=NO_REAL_NAME 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-SCORE: 0:2:485839744:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d40904f1023805d8c X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none On Fri, 13 Jan 2012, Stefan Sch=E4fer wrote: > There are a few possible reasons why the PA blows up. I am more and more= =20 > convinced that it comes from the drive stage. Late in the night i got the I've been thinking along these lines too. I fried an IRF640, replaced it with an IRFP260, and was heartbroken when that fried too. I put another 260 in and half-fried that one -- it still puts out a bit of RF, but the=20 input is a triangle and not a square so the gate impedance is way down. The TX is a class E driven with a juction transistor totem pole. The=20 plan is to replace this with a fet driver eg: 4427. 73 Joe VO1NA This electronic communication is governed by the terms and conditions at http://www.mun.ca/cc/policies/electronic_communications_disclaimer_2011.php