Return-Path: Received: (qmail 8103 invoked from network); 14 Jan 2003 17:19:17 -0000 Received: from warrior.services.quay.plus.net (212.159.14.227) by mailstore with SMTP; 14 Jan 2003 17:19:17 -0000 Received: (qmail 13992 invoked from network); 14 Jan 2003 17:18:39 -0000 Received: from post.thorcom.com (193.82.116.70) by warrior.services.quay.plus.net with SMTP; 14 Jan 2003 17:18:38 -0000 X-Priority: 3 X-MSMail-Priority: Normal X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.12) id 18YUh4-0003lO-00 for rsgb_lf_group-outgoing@blacksheep.org; Tue, 14 Jan 2003 17:17:42 +0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from [194.25.134.82] (helo=mailout05.sul.t-online.com) by post.thorcom.com with esmtp (Exim 4.12) id 18YUh4-0003lF-00 for rsgb_lf_group@blacksheep.org; Tue, 14 Jan 2003 17:17:42 +0000 Received: from fwd03.sul.t-online.de by mailout05.sul.t-online.com with smtp id 18YUh3-00014t-05; Tue, 14 Jan 2003 18:17:41 +0100 Received: from (0482183881-0001@[62.224.51.242]) by fwd03.sul.t-online.com with smtp id 18YUgq-0LRoW0C; Tue, 14 Jan 2003 18:17:28 +0100 From: "jannsen" <0482183881-0001@t-online.de> To: rsgb_lf_group@blacksheep.org References: <18Xprt-0FPHu4C@fwd02.sul.t-online.com> <003801c2b9e6$7a85c940$0500a8c0@charter.net> <5.1.0.14.0.20030114093942.01bbcb60@pb623250.kuleuven.be> X-Mailer: T-Online eMail 2.34 MIME-Version: 1.0 Date: Tue, 14 Jan 2003 18:17:28 +0100 Message-ID: <18YUgq-0LRoW0C@fwd03.sul.t-online.com> X-Sender: 0482183881-0001@t-dialin.net Subject: Re: LF: push/pull Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Status: No, hits=1.0 required=6.0tests=DEAR_SOMEBODY,FROM_ENDS_IN_NUMS,FROM_STARTS_WITH_NUMS, QUOTED_EMAIL_TEXT,REFERENCES,SPAM_PHRASE_05_08, USER_AGENT_TONLINEversion=2.43 X-Spam-Level: * X-SA-Exim-Scanned: Yes Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rsgb_lf_group-outgoing@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false Rik Strobbe schrieb: > Hello Uwe, > ......... > How did you measure this phase shift ? In the past I have noticed that > measuring waveforms at the gate of a FET with the drain open can give very > strange results ... > > 73, Rik ON7YD > > Dear Rik, Alberto, Jim es all, tks for the responses. yes Rik, the drains were open. the PSU was not finished. but today I connected in a first step 50V operating voltage to the PA. I can`t belief it: the phase shift has diminished to abt 2dgr. I know from my other PA, a two channel N-/P-MOSFET equipment, that the scope is ok. but I didn`t measure without the PA operating voltage connected. yes, the Cgs of the IRFP450/451 is vy high. that is the reason I use in the other PA many of the weaker MOSFETs IRF620 for the one channel and IRF9622 for the other. you don`t need the high input power. tks Alberto es Jim that you do not blame on me or my (in)ability doing the things right but suspecting the scope. regards Uwe/dj8wx