Return-Path: Received: (qmail 89329 invoked from network); 11 Dec 2004 10:13:24 -0000 Received: from unknown (HELO ptb-spamcore01.plus.net) (192.168.71.1) by ptb-mailstore02.plus.net with SMTP; 11 Dec 2004 10:13:24 -0000 Received: from mailnull by ptb-spamcore01.plus.net with spamcore-l-b (Exim 4.32; FreeBSD) id 1Cd4aE-000Ic5-Rq for dave@picks.force9.co.uk; Sat, 11 Dec 2004 10:34:39 +0000 Received: from [192.168.67.2] (helo=ptb-mxcore02.plus.net) by ptb-spamcore01.plus.net with esmtp (Exim 4.32; FreeBSD) id 1Cd4aE-000Ic2-O8 for dave@picks.force9.co.uk; Sat, 11 Dec 2004 10:34:38 +0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore02.plus.net with esmtp (Exim) id 1Cd4Ff-000A0T-Ca for dave@picks.force9.co.uk; Sat, 11 Dec 2004 10:13:23 +0000 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Cd4Eu-00022B-VN for rs_out_1@blacksheep.org; Sat, 11 Dec 2004 10:12:36 +0000 Received: from [193.82.116.30] (helo=relay.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Cd4Eu-000222-Jm for rsgb_lf_group@blacksheep.org; Sat, 11 Dec 2004 10:12:36 +0000 Received: from imo-d03.mx.aol.com ([205.188.157.35]) by relay.thorcom.net with esmtp (Exim 4.41) id 1Cd4Eq-0007HK-Pt for rsgb_lf_group@blacksheep.org; Sat, 11 Dec 2004 10:12:36 +0000 Received: from G0MRF@aol.com by imo-d03.mx.aol.com (mail_out_v37_r3.8.) id l.82.1d33c60e (3996) for ; Sat, 11 Dec 2004 05:12:23 -0500 (EST) From: G0MRF@aol.com Message-ID: <82.1d33c60e.2eec2207@aol.com> Date: Sat, 11 Dec 2004 05:12:23 EST To: rsgb_lf_group@blacksheep.org MIME-Version: 1.0 X-Mailer: 9.0 SE for Windows sub 5003 X-SPF-Result: relay.thorcom.net: domain of aol.com designates 205.188.157.35 as permitted sender X-Spam-Score: 1.1 (+) X-Spam-Report: autolearn=no,HTML_30_40=0.809,HTML_MESSAGE=0.001,NO_REAL_NAME=0.285 Subject: LF: 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-Level: * X-Spam-Status: No, hits=1.1 required=5.0 tests=HTML_30_40,HTML_MESSAGE, NO_REAL_NAME 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

Hello.

I'm trying to produce a small PSK31 beacon on a PIC chip using one port (and an XOR gate) to initiate phase change, and others to control the mark space ratio for driving a class D amplifier for the amplitude change.

Question:

With the currently available soundcard decoders, what frequency errors are permissable in the PSK31 waveform which will still decode successfully? Normally 32ms but what tolerance is OK?

Do the decoders lock, and then suddenly lose all decoding ability if the frequency is too far off, or do they just slowly increase their bit error rate with frequency error?

David