Return-Path: Received: (qmail 75060 invoked from network); 22 May 2004 09:04:56 -0000 Received: from unknown (HELO ptb-mxscan03.plus.net) (212.159.14.237) by ptb-mailstore02.plus.net with SMTP; 22 May 2004 09:04:56 -0000 Received: (qmail 62272 invoked from network); 22 May 2004 09:04:56 -0000 X-Filtered-by: Plusnet (hmail v1.01) X-Spam-detection-level: 11 Received: from ptb-mxcore03.plus.net (212.159.14.217) by ptb-mxscan03.plus.net with SMTP; 22 May 2004 09:04:55 -0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore03.plus.net with esmtp (Exim) id 1BRSR5-000G4z-3w for dave@picks.force9.co.uk; Sat, 22 May 2004 10:04:55 +0100 X-Fake-Domain: majordom Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1BRSQE-0000vH-N4 for rs_out_1@blacksheep.org; Sat, 22 May 2004 10:04:02 +0100 Received: from [213.232.95.59] (helo=relay.salmark.net) by post.thorcom.com with esmtp (Exim 4.14) id 1BRSQE-0000v8-4X for rsgb_lf_group@blacksheep.org; Sat, 22 May 2004 10:04:02 +0100 Received: from smtp800.mail.ukl.yahoo.com ([217.12.12.142]) by relay.salmark.net with smtp (Exim 4.24) id 1BRYym-0001jy-83 for rsgb_lf_group@blacksheep.org; Sat, 22 May 2004 17:04:08 +0100 X-Fake-Domain: unknown Received: from unknown (HELO rogersservices) (james.moritz@213.122.162.180 with login) by smtp800.mail.ukl.yahoo.com with SMTP; 22 May 2004 09:03:47 -0000 X-Bad-Message-ID: no DNS (rogersservices) Message-ID: <000b01c43fdb$02f64c20$b4a27ad5@rogersservices> From: "James Moritz" To: rsgb_lf_group@blacksheep.org References: <1BRHm7-0fUSWm0@fwd01.sul.t-online.com> Date: Sat, 22 May 2004 09:57:53 +0100 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2615.200 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2615.200 X-Spam-Score: 0.2 (/) X-Spam-Report: autolearn=no,RCVD_IN_SORBS=0.1,TW_QR=0.077 Subject: Re: LF: RE: looking for first signals ... Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Status: No, hits=0.0 required=5.0 tests=none 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-PN-SPAMFiltered: yes X-Spam-Rating: 2 > Hi Jim, > > your PSK signs are audible in jo43sv. but qrn makes them almost unreadable. > see attachment. > > btw. what type of transmitter do you use for the PSK mode? > > Uwe/dj8wx Dear Uwe, LF Group, Thanks for the report - I transmitted CW/QRSS3 from 1900 - 2100 and 2200 - 2300, and PSK31 from 2100 - 2200. As you observed, the drawback of PSK31 on LF is that every QRN impulse gives you a 50-50 chance of corrupting a bit, and so losing the character. A mode using error correction works better - like VE2IQ's "Coherent" program for example. The TX in use here is the usual class D Decca PA - to get a clean signal, I use an "envelope elimination and restoration" scheme, where the 136kHz drive to the PA is phase modulated, and amplitude modulation is applied to the DC feed to the PA. The phase keying signal is generated by the "Digimode terminal" in DL4YHF's Spectrum Lab software, and the envelope waveform is generated from the phase signal by external hardware. Cheers, Jim Moritz 73 de M0BMU