Return-Path: X-Spam-DCC: paranoid 1002; 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 t9IJN4Rc024589 for ; Sun, 18 Oct 2015 21:23:04 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ZntV8-00021r-Gc for rs_out_1@blacksheep.org; Sun, 18 Oct 2015 20:20:14 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ZntV8-00021i-8l for rsgb_lf_group@blacksheep.org; Sun, 18 Oct 2015 20:20:14 +0100 Received: from parrot.netcom.co.uk ([217.72.171.49]) by relay1.thorcom.net with esmtp (Exim 4.86) (envelope-from ) id 1ZntU4-0005yT-3S for rsgb_lf_group@blacksheep.org; Sun, 18 Oct 2015 20:20:13 +0100 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 18B563273F3 for ; Sun, 18 Oct 2015 20:10:59 +0100 (BST) Received: from [127.0.0.1] (localhost [127.0.0.1]) by sb.abelian.org (Postfix) with ESMTP id 5474F28A1170 for ; Sun, 18 Oct 2015 19:18:56 +0000 (UTC) Message-ID: <5623F0A0.9030902@abelian.org> Date: Sun, 18 Oct 2015 19:18:56 +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: <560DF24D.3050309@abelian.org> <0LmKOI-1aGjgI2N50-00ZuP1@mail.gmx.com> In-Reply-To: X-Scan-Signature: 7aa9ad08848e488e22e0ff1d71f4ef1d Subject: Re: LF: Coherent BPSK on LF using EbNaut 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: 4484 Spent some time today cobbling together a receiver for 137 kHz. System noise measures about 4nV/m equivalent field strength in 1Hz with a BF245B front end but I've not yet attached it to an antenna - that's usually when the trouble starts. The mono audio input of the BT878 video card timestamps fairly well while sampling at 448k samples/second. It's a bit noisy: 3.5 uV RMS in 1Hz at the line input, which means I needed to build in quite a bit of rx gain to overcome the card floor. Because it's a mono audio input I have to mix the GPS PPS and the LF, then separate them again in software. Hopefully soon then, some phase measurements at LF. -- Paul Nicholson --