Return-Path: Received: (qmail 99035 invoked from network); 13 Dec 2004 11:15:42 -0000 Received: from unknown (HELO ptb-spamcore02.plus.net) (192.168.71.3) by ptb-mailstore01.plus.net with SMTP; 13 Dec 2004 11:15:42 -0000 Received: from mailnull by ptb-spamcore02.plus.net with spamcore-l-b (Exim 4.32; FreeBSD) id 1CdoEE-000BbC-D3 for dave@picks.force9.co.uk; Mon, 13 Dec 2004 11:19:03 +0000 Received: from [192.168.67.1] (helo=ptb-mxcore01.plus.net) by ptb-spamcore02.plus.net with esmtp (Exim 4.32; FreeBSD) id 1CdoED-000Bai-1Y for dave@picks.force9.co.uk; Mon, 13 Dec 2004 11:18:57 +0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore01.plus.net with esmtp (Exim 4.30; FreeBSD) id 1CdoAr-00073C-SS for dave@picks.force9.co.uk; Mon, 13 Dec 2004 11:15:29 +0000 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1CdoAZ-0007tk-G9 for rs_out_1@blacksheep.org; Mon, 13 Dec 2004 11:15:11 +0000 Received: from [193.82.116.30] (helo=relay.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1CdoAZ-0007tb-3X for rsgb_lf_group@blacksheep.org; Mon, 13 Dec 2004 11:15:11 +0000 Received: from hestia.herts.ac.uk ([147.197.200.9]) by relay.thorcom.net with esmtp (Exim 4.41) id 1CdoAV-0008Ll-H3 for rsgb_lf_group@blacksheep.org; Mon, 13 Dec 2004 11:15:11 +0000 Received: from altair ([147.197.200.45] helo=altair.herts.ac.uk) by hestia.herts.ac.uk with esmtp (Exim 3.22 #1) id 1Cdo9G-0003pu-00 for rsgb_lf_group@blacksheep.org; Mon, 13 Dec 2004 11:13:50 +0000 Received: from [147.197.164.230] (helo=RD40002) by altair.herts.ac.uk with esmtp (Exim 3.36 #1) id 1Cdo9G-00032e-00 for rsgb_lf_group@blacksheep.org; Mon, 13 Dec 2004 11:13:50 +0000 From: "james moritz" To: rsgb_lf_group@blacksheep.org Date: Mon, 13 Dec 2004 11:13:48 -0000 Message-ID: <000001c4e104$d1fcc920$e6a4c593@RD40002> MIME-Version: 1.0 X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.4510 Importance: Normal In-Reply-To: <001001c4df87$6ab76780$045bfea9@d4f8d8> X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 X-UH-MailScanner: No Virus detected X-SPF-Result: relay.thorcom.net: 147.197.200.9 is neither permitted nor denied by domain of herts.ac.uk X-Spam-Score: 0.3 (/) X-Spam-Report: autolearn=no,HTML_70_80=0.105,HTML_FONTCOLOR_UNKNOWN=0.1,HTML_MESSAGE=0.001,TW_QE=0.077 Subject: LF: RE: Re: Frequency errors on PSK31 Content-Type: text/html; charset=windows-1252 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Status: No, hits=0.2 required=5.0 tests=HTML_70_80, HTML_FONTCOLOR_UNKNOWN,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 X-Spam-Filtered: by PlusNet SpamCORE (v3.00) Content-transfer-encoding: 8bit

Dear Andy, Wolf, LF Group,

But what effect does an error in the bit clock have, i.e. if the period of each bit is not exactly 32ms?

Cheers, Jim Moritz

73 de M0BMU

…As PSK31 uses differential coding, it is the phase change over the 32ms signalling period due to freqeuncy error that is important. If for BPSK, we need to maintain the phase to less than 90 degrees to remove the ambiguity, so 90/360 / 32ms = 7.8Hz freq error permissible.

For noisy signals, the determination of correct phase becomes worse, so error rate will progressively worsen with tuning error.

Andy G4JNT