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 tAML8qlS015525 for ; Sun, 22 Nov 2015 22:08:52 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1a0boX-00082A-4a for rs_out_1@blacksheep.org; Sun, 22 Nov 2015 21:04:49 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1a0boW-000821-Gu for rsgb_lf_group@blacksheep.org; Sun, 22 Nov 2015 21:04:48 +0000 Received: from parrot.netcom.co.uk ([217.72.171.49]) by relay1.thorcom.net with esmtp (Exim 4.86) (envelope-from ) id 1a0bnS-0002fm-9G for rsgb_lf_group@blacksheep.org; Sun, 22 Nov 2015 21:04:47 +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 999123273EB for ; Sun, 22 Nov 2015 20:54:41 +0000 (GMT) Received: from [127.0.0.1] (localhost [127.0.0.1]) by sb.abelian.org (Postfix) with ESMTP id 0ABBD28A014F for ; Sun, 22 Nov 2015 21:03:26 +0000 (UTC) Message-ID: <56522D9D.7090800@abelian.org> Date: Sun, 22 Nov 2015 21:03:25 +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: <564E4046.9030602@gmail.com> <8D2F12F1F72FA45-156C-ECE7D@webmail-vm019.sysops.aol.com> <564F0A31.30604@abelian.org> In-Reply-To: X-Scan-Signature: 0a4643e586472c13187d293ec5d096c2 Subject: Re: LF: EbNaut LF test from iz7slz 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: 5258 Markus wrote: > your direct-sampling LF receiver actually seemed to be > doing rather well! I think so, the rx itself hasn't had any problems. The timing system has got better too with the incentive to reduce the jitter without sacrificing speed of response to clock drift. It seems that whenever I get involved in amateur radio activities I end up with some improvements which get fed back into natural radio reception. I was thinking about oscillators. At LF/MF if messages are short, say less than 30 minutes, the tx frequency only needs to drift by less than about 0.5 Hz/hour. That's within range of a reasonably stable undisciplined oscillator such as an OCXO. I'm thinking that the phase search in the decoder would accommodate that amount of drift. Is it worth trying some transmissions which are not GPS locked? Rx battery is holding up here although I think it must give out overnight at some point. Tomorrow I will recharge it. -- Paul Nicholson --