Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-df02.r1000.mx.aol.com (Internet Inbound) with ESMTP id AB39F38000083; Thu, 28 Jun 2012 06:31:32 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1SkBzM-00056z-Gs for rs_out_1@blacksheep.org; Thu, 28 Jun 2012 11:30:16 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1SkBzM-00056q-2j for rsgb_lf_group@blacksheep.org; Thu, 28 Jun 2012 11:30:16 +0100 Received: from smtpa1.mediabeam.com ([194.25.41.13]) by relay1.thorcom.net with esmtps (TLSv1:AES256-SHA:256) (Exim 4.77) (envelope-from ) id 1SkBzJ-0000Uv-OH for rsgb_lf_group@blacksheep.org; Thu, 28 Jun 2012 11:30:14 +0100 Received: from IMAP4 (balancer7.mediabeam.com [10.100.1.80]) by smtpa1.mediabeam.com (8.13.8/8.13.1) with ESMTP id q5SAUCvh029490 for ; Thu, 28 Jun 2012 12:30:12 +0200 Received: from [192.168.178.33] (37-4-36-228-dynip.superkabel.de [37.4.36.228] (may be forged)) (authenticated bits=0) by smtpa.mediabeam.com (8.13.8/8.13.1) with ESMTP id q5SAUAdS029455 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Thu, 28 Jun 2012 12:30:11 +0200 Message-ID: <4FEC323B.3040805@kabelmail.de> Date: Thu, 28 Jun 2012 12:30:19 +0200 From: DK1IS User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:12.0) Gecko/20120428 Thunderbird/12.0.1 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <4FEB8A2F.3030504@iup.uni-heidelberg.de> In-Reply-To: <4FEB8A2F.3030504@iup.uni-heidelberg.de> X-MIME-Autoconverted: from 8bit to quoted-printable by smtpa.mediabeam.com id q5SAUAdS029455 X-Spam-Score: -0.7 (/) 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: 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, [...] Content analysis details: (-0.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [194.25.41.13 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record X-Scan-Signature: 6ffbd2c9950b634d6cc91f9565b01a8b Subject: Re: LF: 472 kHz PA running at 12 VDC Content-Type: text/plain; charset=ISO-8859-15; format=flowed 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=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: 0:2:439060736:93952408 X-AOL-SCOLL-URL_COUNT: 0 x-aol-sid: 3039ac1d40d64fec328471d7 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Am 28.06.2012 00:33, schrieb Stefan Sch=E4fer: > MF, > > For the homebrewers, here is my prototype of a MF class D PA that=20 > operates at 12 V DC. Input frequency is divided by 4, so a normal HF=20 > TRX can be used (set to 160m / 1.9 MHz) to drive the PA. The input=20 > power must not exceed the range of 1...4 watts. The output power can=20 > be switched in 2 steps between ~15W and up to 100W, depending on the=20 > output impedance and input voltage (10...15V). The output impedance is=20 > not so critical, Z=3DR may be in the range of 30 Ohm to infinity. The=20 > FETs are IRFZ48N types, the driver is a ICL7667CPA. The transformer=20 > uses RF litz wire, 30x0.1mm diameter. I didn't spend to much effort=20 > for optimising the efficiency, not at this power level. During a CW=20 > QSO or longer calls at 50 W RF power the heat sink (which is just a=20 > 3mm thick Al plate) becomes hand warm. > The measured efficiency is 88 % at 18W RF power and 80% at 50W RF=20 > power. The needed power for the driver circuitry is included in this=20 > measurement. > > If someone is interested i may convert the circuit from my mind into a=20 > schematic as a png file. > > 73, Stefan/DK7FC > > https://dl.dropbox.com/u/19882028/MF/DK7FC%20472%20kHz%20PA%2015W%2B100= W.JPG=20 > > > > . > Hi Stefan, me too, please! 73, Tom,DK1IS