Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id x0ON0awI026209 for ; Fri, 25 Jan 2019 00:00:43 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1gmnsI-0004dZ-B4 for rs_out_1@blacksheep.org; Thu, 24 Jan 2019 22:53:30 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1gmnqf-0004dQ-FK for rsgb_lf_group@blacksheep.org; Thu, 24 Jan 2019 22:51:49 +0000 Received: from mail-ed1-x52f.google.com ([2a00:1450:4864:20::52f]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.91) (envelope-from ) id 1gmnqb-0007sj-7r for rsgb_lf_group@blacksheep.org; Thu, 24 Jan 2019 22:51:45 +0000 Received: by mail-ed1-x52f.google.com with SMTP id d39so5900611edb.12 for ; Thu, 24 Jan 2019 14:51:44 -0800 (PST) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:from:date:message-id:subject:to; bh=vkzcbt4Jn5OPqPR9ZB/4F+re5raojrHlvf2j9UU6EKc=; b=lPd1X1gqYDExlDbdv/GZ9qDKtMgojtEezEUSvmgU6j4EB2CJiu8ip+YOh+h+vZIZQp UeyQvsDKy1YuE/z700OwSgCfp5wdQpp5M4QtRd5noxtlbvmAsZ3Ltcul0F6UUNFAD2dL Nomco6Jij8h92GWyTaWSIT1IeEUrO8eSI9JL0G+scvz8lbEldqE2uvkn98zHVaM9FFjU wf4eFjJTGd2pUETOe/eLt3lOr9PbNS+LUf5LOJGgR1BgL7L4WHA84JjpEvO4vxu7Inu8 CC6y6u2pKU3tijT8q5dfd/+vQ+Enx71iwaD1T4D+3W2KsI0GXW47exkFJWOiMsF//ztg p4aA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=vkzcbt4Jn5OPqPR9ZB/4F+re5raojrHlvf2j9UU6EKc=; b=FDuX0MetS4Z900KJzfbdf+I7rDfRNARxysSna54w1wPGepWIorxpg9AAlZxr1spJ2b iWAhOWdlpm/l7g2ADl6ql5K/dUJUTxg+HoncLeb1+Xkchm4HHKeeZi44q0GSKGnrMR5a nOeKtKHWARMBtT/GA4tCtGoJDQp73En74BOCeXifp0VqiC4cOGBFdLTLEmAEadKmTW0H gSf/Dt97aNpP/SUzuLJFaZnOnZ1cdbhBje3maCj2gCsUceVL9V2N3JuJc+K5LCgX12ZW 8cgxDP4QrY5gO9L7/gvVpvxPLkar8AhCsiCBnDW6QdN3WKThupdS0B3XDVZlfutIG259 0gQQ== X-Gm-Message-State: AJcUukcBUC9+ah/93QKeiFUF1Uklzh+hoQfDPs8kZ+rc8z+ioEvEnltc VzEifdCWg2hh9uau7wDF8l4Q79uJT8i01Rg4VvkuXw== X-Google-Smtp-Source: ALg8bN5t/e92f+hyrrYkFtjUmff2Uy1BSdEJk/I7nYIFXh3pUSAcp00C4rz+R6UnHnxtQEh3GHf9dAt9iDDzubH8TMI= X-Received: by 2002:a17:906:54d8:: with SMTP id c24mr2279400ejp.80.1548370303878; Thu, 24 Jan 2019 14:51:43 -0800 (PST) MIME-Version: 1.0 From: Riccardo Zoli Date: Thu, 24 Jan 2019 23:51:32 +0100 Message-ID: To: LF Group X-Spam-Score: 0.3 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see @@CONTACT_ADDRESS@@ for details. Content preview: LF, I'm testing a useful trick to allow a quadrature generator to mantain a stable and nominal phase using a GPS module NEO/LEA-M8T. Normally, an IC 74HC74 is used to generate the quadrature LO signals fo [...] Content analysis details: (0.3 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [2a00:1450:4864:20:0:0:0:52f listed in] [list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.2 FREEMAIL_ENVFROM_END_DIGIT Envelope-from freemail username ends in digit (riccardozoli80[at]gmail.com) 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (riccardozoli80[at]gmail.com) 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: 290c8768709872f914a4ca71ad6bfe49 Subject: LF: NEO-M8T and H-mixer (SDR) Content-Type: multipart/alternative; boundary="000000000000f18b1e05803c0dce" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.7 required=5.0 tests=FROM_ENDS_IN_NUMS,HTML_30_40, HTML_MESSAGE 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 --000000000000f18b1e05803c0dce Content-Type: text/plain; charset="UTF-8" LF, I'm testing a useful trick to allow a quadrature generator to mantain a stable and nominal phase using a GPS module NEO/LEA-M8T. Normally, an IC 74HC74 is used to generate the quadrature LO signals for a H-mixer (typically in a SDR "Softrock style"). Clocking the IC with TP2 signal (f * 4, so 544 kHz to obtain a 136 kHz frequency conversion), there is a 90 deg. step phase ambiguity. Furthermore, with an undesiderate glitch on the reference clock signal, the phase could wrongly rotate. So: resetting (clear) the two D flip-flops of the 74HC74 on rising edge of the 1PPS pulse, already reference for PC audio-card, we can keep nominal phasing which is restored every second. All the best 73 de Riccardo IW4DXW --000000000000f18b1e05803c0dce Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable

LF,

I'm testing a useful trick = to allow a quadrature generator to mantain a stable and nominal phase using= a GPS module NEO/LEA-M8T.
Normally, an IC 74HC74 is= used to generate the quadrature LO signals for a H-mixer (typically in a S= DR "Softrock style").
Clocking the IC with= TP2 signal (f * 4, so 544 kHz to obtain a 136 kHz frequency conversion), t= here is a 90 deg. step phase ambiguity. Furthermore, with an undesiderate g= litch on the reference clock signal, the phase could wrongly rotate.
<= div dir=3D"auto">So: resetting (clear) the two D flip-flops of the 74HC74 o= n rising edge of the 1PPS pulse,=C2=A0already reference for PC audio-card, we can keep nominal phasing which is= restored every second.


All the best


73 de Riccardo IW4DXW



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