Return-Path: Received: (qmail 9378 invoked from network); 25 Jan 2001 10:44:17 -0000 Received: from unknown (HELO murphys-inbound.servers.plus.net) (212.159.14.225) by excalibur.plus.net with SMTP; 25 Jan 2001 10:44:17 -0000 Received: (qmail 7247 invoked from network); 25 Jan 2001 10:38:29 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys with SMTP; 25 Jan 2001 10:38:29 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: from majordom by post.thorcom.com with local (Exim 3.16 #1) id 14Ljgi-0004YN-00 for rsgb_lf_group-outgoing@blacksheep.org; Thu, 25 Jan 2001 10:31:32 +0000 Received: from imo-r05.mx.aol.com ([152.163.225.5]) by post.thorcom.com with esmtp (Exim 3.16 #1) id 14Ljgh-0004YI-00 for rsgb_lf_group@blacksheep.org; Thu, 25 Jan 2001 10:31:31 +0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from G0MRF@aol.com by imo-r05.mx.aol.com (mail_out_v29.5.) id l.e8.f9b0a78 (16937) for ; Thu, 25 Jan 2001 05:30:56 -0500 (EST) From: G0MRF@aol.com Message-ID: Date: Thu, 25 Jan 2001 05:30:56 EST Subject: LF: Articles in QEX To: rsgb_lf_group@blacksheep.org MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 8bit X-Mailer: AOL 5.0 for Windows sub 105 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: For general info: This Jan/Feb QEX magazine from the ARRL has a number of articles of potential interest to the LF constructor / operator. 1) Class E RF power amplifiers by WA1HQC 10 pages on class E design. Includes waveforms that shows the effect of tuning on the voltage / current flowing in the semiconductors. i.e. If your waveform looks like this, then increase C4 etc etc. Ends with 43 references to class E papers including a 92% eff 50kHz to 1.7MHz design with 44kW output. (probably not suited for use on the Ropex frequency Hi) 2) A keyed Power Supply for Class E Amplifiers. " Supply 500W for your class E Power Amp.......for less than $100" Similar to Andy's concept but switching at up to 100k (73k possibilities?). Using 2 IRFP240s and a MC34025 controller 3) More on Atmospheric Ozone and Low frequency propagation. (NM7M) 9 pages of experimental results from monitoring a 55.5kHz transmission between California and Washington state. Looks at single hop and ground wave and some enhanced 'dawn' propagation claimed to be due to "....The Ozonosphere" 73 David G0MRF