Return-Path: Received: from mtain-de03.r1000.mx.aol.com (mtain-de03.r1000.mx.aol.com [172.29.64.203]) by air-mc05.mail.aol.com (v129.10) with ESMTP id MAILINMC054-a96a4daf87671a9; Wed, 20 Apr 2011 21:24:55 -0400 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-de03.r1000.mx.aol.com (Internet Inbound) with ESMTP id 7AA17380000AA; Wed, 20 Apr 2011 21:24:54 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1QCicJ-0007dc-H8 for rs_out_1@blacksheep.org; Thu, 21 Apr 2011 02:23:35 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1QCicI-0007dT-TF for rsgb_lf_group@blacksheep.org; Thu, 21 Apr 2011 02:23:34 +0100 Received: from nm20.bullet.mail.ukl.yahoo.com ([217.146.183.194]) by relay1.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1QCicH-00063w-Nf for rsgb_lf_group@blacksheep.org; Thu, 21 Apr 2011 02:23:34 +0100 Received: from [217.146.183.216] by nm20.bullet.mail.ukl.yahoo.com with NNFMP; 21 Apr 2011 01:23:27 -0000 Received: from [217.146.183.63] by tm9.bullet.mail.ukl.yahoo.com with NNFMP; 21 Apr 2011 01:23:27 -0000 Received: from [127.0.0.1] by omp1032.mail.ukl.yahoo.com with NNFMP; 21 Apr 2011 01:23:27 -0000 X-Yahoo-Newman-Id: 782212.67785.bm@omp1032.mail.ukl.yahoo.com Received: (qmail 49763 invoked from network); 21 Apr 2011 01:23:27 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=btopenworld.com; h=DKIM-Signature:Received:X-Yahoo-SMTP:X-YMail-OSG:X-Yahoo-Newman-Property:Message-ID:From:To:References:In-Reply-To:Subject:Date:MIME-Version:Content-Type:Content-Transfer-Encoding:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE; b=VcriBQoYyduQPBSSUo/P9Y5/WKX07dOV+tKwQh87SU+bKJLtTHHiwKumc4+LhSqo0AyS8oVaGpsxQxvQ6sr89dsUUO1QWJacKZLtHVJuhZSd7pBidK7cInhY/Ynpw+MI+/Z+e4tMIjsQNjMdWzxBfF/SpMFxbgAhLjke8kgmw9c= ; DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=btopenworld.com; s=s1024; t=1303349007; bh=9l/z97ChJvrK7zSL9TrL0cQe2Mgw4GnVgP0e+uw/DHo=; h=Received:X-Yahoo-SMTP:X-YMail-OSG:X-Yahoo-Newman-Property:Message-ID:From:To:References:In-Reply-To:Subject:Date:MIME-Version:Content-Type:Content-Transfer-Encoding:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE; b=mn//pThc5CYrRz5Bp+QRHIXGyy+dbK2iojYCQbH2qgbTwmPtTsFu/JFhxI6v2g51a1u2pbkMslFIGbDB26Q0KfRmvgS7NgulzI2SQSuTvi6q6HrEZFT489VNCiOsD7FCSSjiRl3cNl6fDd8zSULYdsgnE32r2PTZ0ZNK7skWnCw= Received: from JimPC (james.moritz@86.174.24.100 with login) by smtp823.mail.ukl.yahoo.com with SMTP; 21 Apr 2011 01:23:27 +0000 GMT X-Yahoo-SMTP: Cxhli3eswBD1ozmtAojhjrja86kWx0Qm9tycD5QR1DKWrOLgjJcXkw-- X-YMail-OSG: Fl9oDsgVM1miTDD68GDTbg1Wa6DdL48tw0ns0mC7piu1Jlm 4oNOAk3aVxfQYrvVT0ELQZTsJQQQyDjq4niPixtAMSuC_pgFnIpITIvzaHoS Qckps515UqCtMgUO1zKai7b1MMJ5cBx8oHwce3cw7sx3lExjcKeKCh8uXumL nWH9ZAfg2Kjg.v1gOhzHK_bYmdY6YO1fGuSDYHoMiIMQjpyeW8tdoVa45LuS WTTWdstXasPBy7_Ik8m0Tdtj5f2If5b0b8VgKNmmDh3USLJqfd9CbOEilfQO FitdQd5MGvgsZ3ZgN.vy4p.Pz0sr.dlAxsy8rL0B0OPrQArGlKsVkf8IHi.X KW.3V X-Yahoo-Newman-Property: ymail-3 Message-ID: From: "James Moritz" To: References: <4DAF42C1.8010401@telus.net> <4DAF7A16.4040208@telus.net> In-Reply-To: <4DAF7A16.4040208@telus.net> Date: Thu, 21 Apr 2011 02:23:38 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Windows Mail 6.0.6002.18197 X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6002.18417 DomainKey-Status: good (testing) X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,UNPARSEABLE_RELAY=0.001 Subject: Re: LF: MSK with a Class D transmitter...? Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.1 required=5.0 tests=MISSING_OUTLOOK_NAME 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-AUTHENTICATION: mail_rly_antispam_dkim-d258.2 ; domain : btopenworld.com DKIM : pass x-aol-sid: 3039ac1d40cb4daf87667862 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Dear Scott, LF Group, Square up the soundcard output with a limiting amplifier, then feed to class D stage via inverting/non-inverting gates to obtain the compementary gate drives. The sound card output will be a nice sine wave; provided the limiting amplifier limits in a symmetrical fashion, the resulting gate drive signals will be close enough to 50% duty cycle. Using a divide-by-two counter to obtain complementary gate drive signals is quite convenient if you have to divide the carrier frequency source anyway, but it isn't essential to do this. Cheers, Jim Moritz 73 de M0BMU