Return-Path: Received: (qmail 50733 invoked from network); 20 Mar 2004 18:45:31 -0000 Received: from unknown (HELO ptb-mxscan02.plus.net) (212.159.14.236) by ptb-mailstore01.plus.net with SMTP; 20 Mar 2004 18:45:31 -0000 Received: (qmail 41701 invoked from network); 20 Mar 2004 18:53:26 -0000 X-Filtered-by: Plusnet (hmail v1.01) X-Spam-detection-level: 11 Received: from ptb-mxcore02.plus.net (212.159.14.216) by ptb-mxscan02.plus.net with SMTP; 20 Mar 2004 18:53:26 -0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore02.plus.net with esmtp (Exim) id 1B4lb3-000AjU-UG for dave@picks.force9.co.uk; Sat, 20 Mar 2004 18:53:26 +0000 X-Fake-Domain: majordom Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1B4laS-0005SH-HJ for rs_out_1@blacksheep.org; Sat, 20 Mar 2004 18:52:48 +0000 Received: from [213.232.95.59] (helo=relay.salmark.net) by post.thorcom.com with esmtp (Exim 4.14) id 1B4laS-0005S8-21 for rsgb_lf_group@blacksheep.org; Sat, 20 Mar 2004 18:52:48 +0000 Received: from postbode02.zonnet.nl ([62.58.50.89]) by relay.salmark.net with esmtp (Exim 4.24) id 1B4tVm-0005ZG-1e for rsgb_lf_group@blacksheep.org; Sun, 21 Mar 2004 03:20:30 +0000 Received: (qmail 25108 invoked by uid 10); 20 Mar 2004 18:52:12 -0000 Received: (vexira-qq 24891-A48F76D2 invoked from network) 20 Mar 2004 19:52:11 +0100 X-Fake-Domain: unknown Received: from unknown (HELO ibm) ([62.59.190.215]) (envelope-sender ) by postbode02.zonnet.nl (qmail-ldap-1.03) with SMTP for < >; 20 Mar 2004 18:52:11 -0000 X-Bad-Message-ID: no DNS (ibm) Message-ID: <000b01c40eab$3d59ac60$2102000a@ibm> From: "Dick" To: rsgb_lf_group@blacksheep.org References: <000801c40ea5$67af4930$bb4036d2@mcalevey> Date: Sat, 20 Mar 2004 19:42:17 +0100 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: 6.24.0.7; VDF: 6.24.0.64; host: postbode02.zonnet.nl) X-Spam-Score: 1.0 (+) X-Spam-Report: 0.9 FROM_ENDS_IN_NUMS From: ends in numbers 0.1 RCVD_IN_SORBS RBL: SORBS: sender is listed in SORBS [62.59.190.215 listed in dnsbl.sorbs.net] Subject: LF: component replacements Content-Type: text/plain; charset=koi8-r; 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, I'm not an expert in all the special types of components around, so therefore some questions here. In several transmitter designs I found a skottky diode MBR150 in the gates of the FET's. As I don't have them here (yet?) I was wondering if these can be replaced by other types of (schottky) diodes. First question: the MBR150 is a 50V/1A type. Can I use types with higher currents, and how important is the voltage rated? Second question: as fas as I understand schottky diodes are extremly fast, but what about the use of so called 'very fast soft-recovery avalanche'diodes, like the BYV26 or BYV 28 with Trr of 25ns? I have plenty of them in my junkbox, but really no idea whether these are fast and/or usable for this purpose. Finally an question about David, G0MRF's 300W transmitter (actually should ask it David personally......) that one uses an H11L1 optocoupler with schmitt-trigger output in it's protection circuit. Wonder if that one can be replaced by a normal transistor type output optocoupler. It is a bit frustrating to find some components so hard to find here in Holland....... Some designs seem to use several "exotic" components which make it rather difficult to build them right away....... 73 Dick, pa4vhf