Return-Path: Received: from mtain-me04.r1000.mx.aol.com (mtain-me04.r1000.mx.aol.com [172.29.96.140]) by air-mb08.mail.aol.com (v129.4) with ESMTP id MAILINMB081-a7d34d2c414d275; Tue, 11 Jan 2011 06:38:53 -0500 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-me04.r1000.mx.aol.com (Internet Inbound) with ESMTP id ACE0F380000D9; Tue, 11 Jan 2011 06:38:52 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1PccXz-0007du-4G for rs_out_1@blacksheep.org; Tue, 11 Jan 2011 11:37:55 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1PccXy-0007dl-OD for rsgb_lf_group@blacksheep.org; Tue, 11 Jan 2011 11:37:54 +0000 Received: from cavuit02.kulnet.kuleuven.be ([134.58.240.44]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1PccXw-0006oU-5q for rsgb_lf_group@blacksheep.org; Tue, 11 Jan 2011 11:37:54 +0000 Received: from smtps01.kuleuven.be (smtpshost01.kulnet.kuleuven.be [134.58.240.74]) by cavuit02.kulnet.kuleuven.be (Postfix) with ESMTP id CE19B75A06E for ; Tue, 11 Jan 2011 12:37:41 +0100 (CET) Received: from ICTS-S-HUB-N4.luna.kuleuven.be (icts-s-hub-n4.luna.kuleuven.be [10.112.9.14]) by smtps01.kuleuven.be (Postfix) with ESMTP id A85B631E702 for ; Tue, 11 Jan 2011 12:37:41 +0100 (CET) Received: from ICTS-S-EXC2-CA.luna.kuleuven.be ([10.112.11.13]) by ICTS-S-HUB-N4.luna.kuleuven.be ([10.112.9.14]) with mapi; Tue, 11 Jan 2011 12:37:42 +0100 X-Kuleuven: This mail passed the K.U.Leuven mailcluster From: Rik Strobbe To: "rsgb_lf_group@blacksheep.org" Date: Tue, 11 Jan 2011 12:37:40 +0100 Thread-Topic: RF ammeter question Thread-Index: AcuxgdtdUg7+MUxdQtG/xcjflxDmdwAAU9H7 Message-ID: References: <201101111216460781.5C69093B@smtp2.numeo.fr> In-Reply-To: <201101111216460781.5C69093B@smtp2.numeo.fr> Accept-Language: nl-NL, nl-BE Content-Language: nl-BE X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: nl-NL, nl-BE MIME-Version: 1.0 X-KULeuven-Information: Katholieke Universiteit Leuven X-KULeuven-Scanned: Found to be clean X-KULeuven-Envelope-From: rik.strobbe@fys.kuleuven.be X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: LF: RE: RF ammeter question Content-Type: text/plain; charset="us-ascii" 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=0.0 required=5.0 tests=TO_ADDRESS_EQ_REAL 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-sid: 3039ac1d608c4d2c414c4e1e X-AOL-IP: 195.171.43.25 X-Mailer: Unknown (No Version) John, 1N4148 is a relatively fast small signal diode (4ns switching time) It can handle 100V (reverse) and 200mA 1N4007 is a rectifier diode (1000V / 1A). My datasheet doe not mention the= switching time, but it most likely much slower. Common replacements for 1N4148 are 1N4448 and 1N914 73, Rik ON7YD ________________________________________ Van: owner-rsgb_lf_group@blacksheep.org [owner-rsgb_lf_group@blacksheep.or= g] namens John RABSON [john.rabson@numeo.fr] Verzonden: dinsdag 11 januari 2011 12:16 Aan: rsgb_lf_group@blacksheep.org Onderwerp: LF: RF ammeter question LF, I have built the fullwave rectified version of the design shown on page 10= .33 of the RSGB Handbook 10th edition. It reads correctly at 25kHz but on= ly show 1/3 of the correct value at 136. Not having any 1N4148 diodes I used 1N4007s. Might this be the cause of= the problem? 73 John F5VLF