Return-Path: X-Spam-DCC: paranoid 1170; 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 t9ODgE1v015030 for ; Sat, 24 Oct 2015 15:42:14 +0200 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Zpz1z-0005ZE-Hj for rs_out_1@blacksheep.org; Sat, 24 Oct 2015 14:38:47 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Zpz1z-0005Z5-46 for rsgb_lf_group@blacksheep.org; Sat, 24 Oct 2015 14:38:47 +0100 Received: from parrot.netcom.co.uk ([217.72.171.49]) by relay1.thorcom.net with esmtp (Exim 4.86) (envelope-from ) id 1Zpz0u-0004ij-VB for rsgb_lf_group@blacksheep.org; Sat, 24 Oct 2015 14:38:46 +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 32CFF32740A for ; Sat, 24 Oct 2015 14:29:19 +0100 (BST) Received: from [127.0.0.1] (localhost [127.0.0.1]) by sb.abelian.org (Postfix) with ESMTP id D575428A0134 for ; Sat, 24 Oct 2015 13:37:23 +0000 (UTC) Message-ID: <562B8993.5060900@abelian.org> Date: Sat, 24 Oct 2015 13:37:23 +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: <8D2DC03E4BF816E-12A8-1699E1@webmail-vd008.sysops.aol.com> <8D2DC5A1D835784-12CC-5A8042@webmail-vm111.sysops.aol.com> In-Reply-To: <8D2DC5A1D835784-12CC-5A8042@webmail-vm111.sysops.aol.com> X-Scan-Signature: 3f8d74a8c70dd416d0a3a1dbcb9bb89f 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: 4616 Having decoded the 20:00 UT 22 character message, I re-encoded it and used the symbols to phase modulate the received signal. The result is an unmodulated carrier which I can take measurements from. Here's the reconstructed carrier spectrum: http://abelian.org/tmp/lf151024a.gif The peak is at 137502.239997 Hz +/- 1uHz. Phase measured in 10 intervals was interval_start degrees_lead 2015-10-23_20:00:00 159.9 2015-10-23_20:02:12 158.3 2015-10-23_20:04:25 157.9 2015-10-23_20:06:38 152.0 2015-10-23_20:08:51 102.4 2015-10-23_20:11:04 153.5 2015-10-23_20:13:16 154.8 2015-10-23_20:15:29 167.1 2015-10-23_20:17:42 169.1 2015-10-23_20:19:55 136.0 Then I repeated the process, but for the undecoded 23:00 message (knowing from Markus' decode that the message was 'IZ7SLZ') But I get nothing above noise. For the other hourly transmissions 00:00 to 06:00 I did the same, but nothing shows above noise, not even a hint of anything there. The noise floor didn't change much overnight. I'd expect to see a reconstructed carrier about 10dB above noise if the power reduction was 10dB. I'm guessing that the 10W tx power is less than 10W, probably less than 5W. That's one possibility. Alternatively, the tx oscillator lost its GPS lock and the carrier began drifting. The carrier 20:35-20:43 had an offset of 1,338 mHz which suggests the tx oscillator became unlocked. We need to measure the phase of some long distance carriers to see if the LF band can use very narrow bandwidth coherent BPSK. So far, we know it is good for 20 minutes at range 2022 km. -- Paul Nicholson --