Return-Path: <owner-rsgb_lf_group@blacksheep.org> Received: (qmail 6461 invoked from network); 24 Sep 2003 21:34:05 -0000 Received: from netmail02.services.quay.plus.net (212.159.14.221) by mailstore with SMTP; 24 Sep 2003 21:34:05 -0000 Received: (qmail 13055 invoked by uid 10001); 24 Sep 2003 21:34:04 -0000 X-Filtered-by: Plusnet (hmail v1.01) X-Spam-detection-level: 11 Received: from post.thorcom.com (193.82.116.70) by netmail02.services.quay.plus.net with SMTP; 24 Sep 2003 21:33:49 -0000 X-Fake-Domain: majordom Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1A2HFv-0001SG-N7 for rsgb_lf_group-outgoing@blacksheep.org; Wed, 24 Sep 2003 22:33:03 +0100 Received: from [62.253.164.48] (helo=mta8-svc.business.ntl.com) by post.thorcom.com with esmtp (Exim 4.14) id 1A2HFr-0001S7-Nq for rsgb_lf_group@blacksheep.org; Wed, 24 Sep 2003 22:32:59 +0100 X-Fake-Domain: p4o2b7 Received: from p4o2b7 ([62.252.208.61]) by mta8-svc.business.ntl.com (InterMail vM.4.01.03.37 201-229-121-137-20020806) with SMTP id <20030924213258.VVUZ29034.mta8-svc.business.ntl.com@p4o2b7> for <rsgb_lf_group@blacksheep.org>; Wed, 24 Sep 2003 22:32:58 +0100 X-Bad-Message-ID: no DNS (p4o2b7) Message-ID: <000001c382db$4ebf1460$5967fea9@p4o2b7> From: "Ian Kyle" <ianj.kyle@virgin.net> To: rsgb_lf_group@blacksheep.org References: <AAEBLFEBLAPDIHJAGBICGEHFCDAA.g4wgt@talkgas.net> Date: Wed, 24 Sep 2003 13:31:35 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Subject: LF: Re: Output Power. Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Status: No, hits=0.3 required=5.0tests=DATE_IN_PAST_06_12,REFERENCESversion=2.55 X-Spam-Checker-Version: SpamAssassin 2.55 (1.174.2.19-2003-05-19-exp) 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: rsgb_lf_group-outgoing@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-Spam-Rating: 2 Hi Gary, Easy to measure power at 136. I use " V squared over R" in a dummy load consisting of four wirewounds in series/parallel and measure the peak voltage with an very ordinary "cooking" chopped beam 'scope. Same system used to calibrate the current meters,and as the basis for a "scope-match" unit. A 'pick-and-shovel' way of looking for match is to set up the TX for a given power into the dummy (say 25W) and note the input DC current. Leave the settings alone and put the antenna on. Adjust tune and/or match to get the same current. You'll be in the park - if not exactly in the Directors Box. I have given up on the BK having tried Jims mods and found that ANY departure from the manufacturers component values banjaxes either voltage or waveform or both at the drive stage, and now intend to simply use the PSU and two of the MOSFETS in push-pull into a tuned cirrcuit and drive them with a commercial 10W audio chip good to 120KHz that my "technical adviser" GI1PHF found whilst clearing up his garage - thus maintaining my policy of minimum expenditure. Have been running captures pretty well every night for the last few weeks without getting anything other than a reduction in free disc space. Have fun. Ian GI8AYZ/MI0AYZ