Return-Path: Received: (qmail 28291 invoked from network); 25 Apr 2003 14:34:23 -0000 Received: from warrior.services.quay.plus.net (212.159.14.227) by mailstore with SMTP; 25 Apr 2003 14:34:23 -0000 Received: (qmail 20365 invoked from network); 25 Apr 2003 14:34:05 -0000 Received: from post.thorcom.com (193.82.116.70) by warrior.services.quay.plus.net with SMTP; 25 Apr 2003 14:34:04 -0000 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1994Du-0005F4-0e for rsgb_lf_group-outgoing@blacksheep.org; Fri, 25 Apr 2003 15:30:46 +0100 Received: from [194.73.73.93] (helo=rhenium.btinternet.com) by post.thorcom.com with esmtp (Exim 4.14) id 1994Di-0005Et-4T for rsgb_lf_group@blacksheep.org; Fri, 25 Apr 2003 15:30:34 +0100 Received: from dial81-135-11-16.in-addr.btopenworld.com ([81.135.11.16] helo=Main) by rhenium.btinternet.com with smtp (Exim 3.22 #23) id 1994Dh-0001IK-00 for rsgb_lf_group@blacksheep.org; Fri, 25 Apr 2003 15:30:33 +0100 Message-ID: <000901c30b37$258cd800$6507a8c0@Main> From: "Alan Melia" To: "LF-Group" Date: Fri, 25 Apr 2003 15:29:18 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.50.4522.1200 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Subject: LF: something for the weekend ?? Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Status: No, hits=0.0 required=5.0tests=noneversion=2.53 X-Spam-Checker-Version: SpamAssassin 2.53 (1.174.2.15-2003-03-30-exp) X-SA-Exim-Scanned: Yes Sender: 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 Hi Andy, I am afraid my Terman "Radio Engineers Handbook" 1943 Page 19 gives Sin(A).Cos(B)= Sin(A-B)+Sin(A+B) ....if we forget about the 0.5 factor. but it agrees on the others. This gives you Cos(A-B) + Cos(A+B) out of the top after the 90deg. phase shift and Cos(A-B) - Cos(A+B) out of the bottom ....again cancelling one sideband. I was toying with the idea that Sin(A+pi/2)=Cos(A) but Cos(A+pi/2)= -Sin(A) but that seems irrelevant. Cheers de Alan G3NYK alan.melia@btinternet.com