Return-Path: Received: (qmail 29716 invoked from network); 15 Nov 2002 13:50:58 -0000 Received: from murphys.services.quay.plus.net (212.159.14.225) by mailstore with SMTP; 15 Nov 2002 13:50:58 -0000 Received: (qmail 29664 invoked from network); 15 Nov 2002 12:49:13 -0000 Received: from post.thorcom.com (193.82.116.70) by murphys.services.quay.plus.net with SMTP; 15 Nov 2002 12:49:13 -0000 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.10) id 18Cft1-00067d-00 for rsgb_lf_group-outgoing@blacksheep.org; Fri, 15 Nov 2002 12:47:51 +0000 Received: from [194.73.73.116] (helo=lutetium) by post.thorcom.com with esmtp (Exim 4.10) id 18Cft0-00067U-00 for rsgb_lf_group@blacksheep.org; Fri, 15 Nov 2002 12:47:50 +0000 Received: from host217-35-31-236.in-addr.btopenworld.com ([217.35.31.236] helo=dellboy) by lutetium with smtp (Exim 3.22 #15) id 18Cft0-0004mq-00 for rsgb_lf_group@blacksheep.org; Fri, 15 Nov 2002 12:47:50 +0000 Message-ID: <001701c28ca5$4f6f9380$1700a8c0@home> From: "Dave Pick" To: rsgb_lf_group@blacksheep.org References: <3DD35969.30941.58250D@localhost> <004801c28bb7$b2c00580$015e89d9@jackie> <5.1.0.14.0.20021114135046.02a5e660@pb623250.kuleuven.be> <000b01c28c92$7ca50aa0$0504210a@c.scope> Date: Fri, 15 Nov 2002 12:48:34 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4920.2300 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Subject: LF: Re: Calibrating LF Current Meters Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Status: No, hits=-0.3 required=5.0tests=QUOTED_EMAIL_TEXT,REFERENCES,SPAM_PHRASE_00_01, USER_AGENT_OEversion=2.42 Sender: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Hugh. Quick and dirty way.... Fire up a 100W jap rig on 160 into a 50 ohm load. At full welly of 100W you should read 1.4A into the load. If the tx has a power meter or you have an external one in line then you can set it to exactly 100W. Most rigs give about 110 or 120 flat-out. If it were 120W you should read 1.55A so you won't be far out. I just calibrated mine against a thermocouple ammeter which I checked with 50Hz and a DMM. Dave G3YXM. > But how can I calibrate it - how do I know that an indicated Amp really is > an Amp. > My DVMs, being intended for mains current measurement, don't have the > frequency response. > How have other people done it ? Any ideas ? > 73 > Hugh M0WYE > > > >