Return-Path: Received: (qmail 22057 invoked from network); 18 May 2004 20:19:09 -0000 Received: from unknown (HELO ptb-mxscan03.plus.net) (212.159.14.237) by ptb-mailstore01.plus.net with SMTP; 18 May 2004 20:19:09 -0000 Received: (qmail 10476 invoked from network); 18 May 2004 20:19:09 -0000 X-Filtered-by: Plusnet (hmail v1.01) X-Spam-detection-level: 11 Received: from ptb-mxcore03.plus.net (212.159.14.217) by ptb-mxscan03.plus.net with SMTP; 18 May 2004 20:19:07 -0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore03.plus.net with esmtp (Exim) id 1BQB3L-0002aR-R0 for dave@picks.force9.co.uk; Tue, 18 May 2004 21:19:07 +0100 X-Fake-Domain: majordom Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1BQB2O-0002Kq-2k for rs_out_1@blacksheep.org; Tue, 18 May 2004 21:18:08 +0100 Received: from [213.232.95.59] (helo=relay.salmark.net) by post.thorcom.com with esmtp (Exim 4.14) id 1BQB2N-0002KC-G6 for rsgb_lf_group@blacksheep.org; Tue, 18 May 2004 21:18:07 +0100 Received: from postbode01.zonnet.nl ([62.58.50.88]) by relay.salmark.net with esmtp (Exim 4.24) id 1BQHav-0001qd-Dq for rsgb_lf_group@blacksheep.org; Wed, 19 May 2004 04:18:13 +0100 Received: (qmail 17122 invoked by uid 10); 18 May 2004 20:17:38 -0000 Received: (vexira-qq 17069-3924F063 invoked from network) 18 May 2004 22:17:37 +0200 X-Fake-Domain: unknown Received: from unknown (HELO ibm) ([62.59.190.104]) (envelope-sender ) by postbode01.zonnet.nl (qmail-ldap-1.03) with SMTP for < >; 18 May 2004 20:17:37 -0000 X-Bad-Message-ID: no DNS (ibm) Message-ID: <003201c43d13$c22fc500$2102000a@ibm> From: "Dick" To: rsgb_lf_group@blacksheep.org Date: Tue, 18 May 2004 22:06:21 +0200 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2615.200 X-MIMEOLE: Produced By Microsoft MimeOLE V5.00.2615.200 X-AntiVirus: checked by Vexira MailArmor (version: 2.0.1.16; VAE: 6.25.0.3; VDF: 6.25.0.69; host: postbode01.zonnet.nl) X-Spam-Score: 1.0 (+) X-Spam-Report: autolearn=no,FROM_ENDS_IN_NUMS=0.869,RCVD_IN_SORBS=0.1 Subject: LF: output transformer problems Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Status: No, hits=0.9 required=5.0 tests=FROM_ENDS_IN_NUMS 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-PN-SPAMFiltered: yes X-Spam-Rating: 2 Hello all, due to circumstances I'll have less time to work on the transmitter. Meanwhile I tried several other transformers, as well as some other things, like disconnecting the Scottky diodes and the 470nF C's . Now I have 6R8 from the TC4426 direct to the gates, which are grounded with 47k resistor. I tried all kind of things around the FET's with other C's to ground or with C-R to ground etc. Some progress has been made, but still difficult. The ouput filter seems to have a quite large influence on the over all drain current. Also the value of the capacitor that grounds the centre tap is important. In my case I found better results at 330nF. Several available cores tested, like 3C11 (white) and 3E1 (green) both 36mm. Also tried an T106-26 from an old computer SMPS. Wonder what current I should have when applying lower supply voltages to the FET's. For example. what currents to others have at 15V or 20V or so. 73, Dick, pa4vhf