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 t9QGrp5g020782 for ; Mon, 26 Oct 2015 17:53:52 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Zqkup-0005dC-5I for rs_out_1@blacksheep.org; Mon, 26 Oct 2015 16:46:35 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Zqkuo-0005d3-T1 for rsgb_lf_group@blacksheep.org; Mon, 26 Oct 2015 16:46:34 +0000 Received: from parrot.netcom.co.uk ([217.72.171.49]) by relay1.thorcom.net with esmtp (Exim 4.86) (envelope-from ) id 1Zqktk-0002ni-LP for rsgb_lf_group@blacksheep.org; Mon, 26 Oct 2015 16:46:33 +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 4E02A3273F4 for ; Mon, 26 Oct 2015 16:37:02 +0000 (GMT) Received: from [127.0.0.1] (localhost [127.0.0.1]) by sb.abelian.org (Postfix) with ESMTP id 5F96428A0184 for ; Mon, 26 Oct 2015 16:45:10 +0000 (UTC) Message-ID: <562E5896.2060407@abelian.org> Date: Mon, 26 Oct 2015 16:45:10 +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> <562B8993.5060900@abelian.org> In-Reply-To: <562B8993.5060900@abelian.org> X-Scan-Signature: b77892ad90d0261eaf071f4f6cf31464 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: 4652 Today I ended my brief foray into 137 kHz. The battery was going flat on the rx so I took it down. Reception at LF seems quite easy compared to VLF: much lower noise levels and much less interference. Strong Opera and WSPR transmissions can be a problem and Loran provides a rich spectrum of sidebands, but apart from that it seems fairly clean. Coherent BPSK tests with DF6NM and IZ7SLZ were successful down to symbol periods of 0.1 seconds. Channel capacity exceeded 9000 bits/hour on a 1Mm daytime path with 0.3W ERP using just E-field reception. Phase remains stable on 2Mm paths for at least a couple of hours during daytime. Unfortunately there were no other transmissions available with which to measure longer paths. Some distant carrier transmissions would have been very useful. If there is any interest in doing more tests I can put the rx back out after some modifications to improve performance. Thanks to Domenico and Markus for providing some interesting signals to play with. -- Paul Nicholson --