Return-Path: X-Spam-DCC: paranoid 1233; Body=2 Fuz1=2 Fuz2=2 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-0.5 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, FORGED_RCVD_HELO,RATWARE_GECKO_BUILD autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id tBDE3VxE016427 for ; Sun, 13 Dec 2015 15:03:31 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1a87C2-0005SY-Q0 for rs_out_1@blacksheep.org; Sun, 13 Dec 2015 14:00:06 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1a87C2-0005SP-I3 for rsgb_lf_group@blacksheep.org; Sun, 13 Dec 2015 14:00:06 +0000 Received: from parrot.netcom.co.uk ([217.72.171.49]) by relay1.thorcom.net with esmtp (Exim 4.86) (envelope-from ) id 1a87Ay-0007WT-Cp for rsgb_lf_group@blacksheep.org; Sun, 13 Dec 2015 14:00:05 +0000 Received: from sb.abelian.org (i-194-106-52-83.freedom2surf.net [194.106.52.83]) by parrot.netcom.co.uk (Postfix) with ESMTP id 56DED327402 for ; Sun, 13 Dec 2015 13:49:30 +0000 (GMT) Received: from [127.0.0.1] (localhost [127.0.0.1]) by sb.abelian.org (Postfix) with ESMTP id 66ACC28A0112 for ; Sun, 13 Dec 2015 13:58:43 +0000 (UTC) Message-ID: <566D7992.2070207@abelian.org> Date: Sun, 13 Dec 2015 13:58:42 +0000 From: Paul Nicholson User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <56686FA0.4050707@gmail.com> <56695B15.6010203@abelian.org> <56696950.1040300@abelian.org> <5669B7CE.1090601@freenet.de> <5669E1E3.6070008@abelian.org> <566D6597.4070901@freenet.de> <566D73CD.1070805@freenet.de> In-Reply-To: <566D73CD.1070805@freenet.de> X-Scan-Signature: 5c335215f1b3de26d890ee84d49616ce Subject: Re: LF: LF EbNaut test from JN80 on 137370 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit 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-Scanned-By: MIMEDefang 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 5793 If the signal is on the high side of the oscillator, Q should lead I after the mixer, s(t) = sin(wc * t); // Signal, wc = 2 * pi * Fc i(t) = sin(wc * t) * cos( wo * t); // LO, wo = 2 * pi * Fo q(t) = sin(wc * t) * sin( wo * t); expands to i(t) = 1/2 * { sin((wc+wo)*t) + sin((wc-wo)*t) } q(t) = 1/2 * { cos((wc-wo)*t) - cos((wc+wo)*t) } which after LPF to remove the wc+wo component leaves i(t) ~= 1/2 * sin((wc-wo)*t) q(t) ~= 1/2 * cos((wc-wo)*t) which has q(t) leading i(t) by 90 degrees. The above are the polarities used by vlfrx-tools and ebnaut. On the scope, signal at 77500 Hz and LO at 77490 Hz looks like http://abelian.org/vlf/tmp/151213a.gif with Q (the 2nd channel) peaking 90 deg before I. -- Paul Nicholson --