Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dd02.r1000.mx.aol.com (Internet Inbound) with ESMTP id 22CB5380000BD; Thu, 28 Jun 2012 06:43:43 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1SkCBk-0005FI-1L for rs_out_1@blacksheep.org; Thu, 28 Jun 2012 11:43:04 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1SkCBj-0005F9-Js for rsgb_lf_group@blacksheep.org; Thu, 28 Jun 2012 11:43:03 +0100 Received: from out1.ip03ir2.opaltelecom.net ([62.24.128.239]) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1SkCBh-0000cE-RW for rsgb_lf_group@blacksheep.org; Thu, 28 Jun 2012 11:43:02 +0100 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: ArQFAFU07E9cF/xG/2dsb2JhbABFigmqDYIfgQiCEwUBAQUIAQEDJQEjAiwBAQMFAgEDEQQBAQolFAEEGgYWCAYTCgECAgEBh34HqhCPEwSLNxuCU4McA41Nl2iCXw X-IronPort-AV: E=Sophos;i="4.77,491,1336345200"; d="scan'208";a="391249987" Received: from host-92-23-252-70.as13285.net (HELO xphd97xgq27nyf) ([92.23.252.70]) by out1.ip03ir2.opaltelecom.net with SMTP; 28 Jun 2012 11:42:59 +0100 Message-ID: <001f01cd551a$c5e740b0$0401a8c0@xphd97xgq27nyf> From: "mal hamilton" To: References: <4FEB8A2F.3030504@iup.uni-heidelberg.de> <4FEC323B.3040805@kabelmail.de> Date: Thu, 28 Jun 2012 10:42:53 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 X-Spam-Score: 3.1 (+++) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: At 50 watts slightly more efficient than a Valve Class C and at 100 watts about the same !! g3kev ----- Original Message ----- From: "DK1IS" To: Sent: Thursday, June 28, 2012 10:30 AM Subject: Re: LF: 472 kHz PA running at 12 VDC [...] Content analysis details: (3.1 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [62.24.128.239 listed in list.dnswl.org] 1.0 FSL_XM_419 Old OE version in X-Mailer only seen in 419 spam -0.0 SPF_PASS SPF: sender matches SPF record 0.5 FSL_UA FSL_UA 1.6 AXB_XMAILER_MIMEOLE_OL_024C2 AXB_XMAILER_MIMEOLE_OL_024C2 X-Scan-Signature: 5f132ffce194fb93f2267a462d849f2b Subject: Re: LF: 472 kHz PA running at 12 VDC Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: 8bit 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=none 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-SCOLL-SCORE: 0:2:496206688:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d408e4fec355f64bf X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none At 50 watts slightly more efficient than a Valve Class C and at 100 watts about the same !! g3kev ----- Original Message ----- From: "DK1IS" To: Sent: Thursday, June 28, 2012 10:30 AM Subject: Re: LF: 472 kHz PA running at 12 VDC Am 28.06.2012 00:33, schrieb Stefan Schäfer: > MF, > > For the homebrewers, here is my prototype of a MF class D PA that > operates at 12 V DC. Input frequency is divided by 4, so a normal HF > TRX can be used (set to 160m / 1.9 MHz) to drive the PA. The input > power must not exceed the range of 1...4 watts. The output power can > be switched in 2 steps between ~15W and up to 100W, depending on the > output impedance and input voltage (10...15V). The output impedance is > not so critical, Z=R may be in the range of 30 Ohm to infinity. The > FETs are IRFZ48N types, the driver is a ICL7667CPA. The transformer > uses RF litz wire, 30x0.1mm diameter. I didn't spend to much effort > for optimising the efficiency, not at this power level. During a CW > QSO or longer calls at 50 W RF power the heat sink (which is just a > 3mm thick Al plate) becomes hand warm. > The measured efficiency is 88 % at 18W RF power and 80% at 50W RF > power. The needed power for the driver circuitry is included in this > measurement. > > If someone is interested i may convert the circuit from my mind into a > schematic as a png file. > > 73, Stefan/DK7FC > > https://dl.dropbox.com/u/19882028/MF/DK7FC%20472%20kHz%20PA%2015W%2B100W.JPG > > > > . > Hi Stefan, me too, please! 73, Tom,DK1IS