Return-Path: <majordom@post.thorcom.com> Received: (qmail 8793 invoked from network); 16 Feb 2002 16:32:37 -0000 Content-Transfer-Encoding: 8bit Received: from unknown (HELO murphys-inbound.services.quay.plus.net) (212.159.14.225) by excalibur.plus.net with SMTP; 16 Feb 2002 16:32:37 -0000 X-Priority: 3 X-MSMail-Priority: Normal Received: (qmail 8055 invoked from network); 16 Feb 2002 16:32:34 -0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys.services.quay.plus.net with SMTP; 16 Feb 2002 16:32:34 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 16c57k-00057b-00 for rsgb_lf_group-outgoing@blacksheep.org; Sat, 16 Feb 2002 13:43:32 +0000 Received: from hestia.herts.ac.uk ([147.197.200.9]) by post.thorcom.com with esmtp (Exim 3.33 #2) id 16c57j-00057W-00 for rsgb_lf_group@blacksheep.org; Sat, 16 Feb 2002 13:43:31 +0000 Received: from gemini ([147.197.200.44] helo=gemini.herts.ac.uk) by hestia.herts.ac.uk with esmtp (Exim 3.22 #1) id 16c56r-0001Yc-00 for rsgb_lf_group@blacksheep.org; Sat, 16 Feb 2002 13:42:37 +0000 Received: from [147.197.232.252] (helo=rsch-15.herts.ac.uk) by gemini.herts.ac.uk with esmtp (Exim 3.33 #1) id 16c56r-0003EG-00 for rsgb_lf_group@blacksheep.org; Sat, 16 Feb 2002 13:42:37 +0000 Message-ID: <5.1.0.14.0.20020216125234.00a852b0@gemini.herts.ac.uk> X-Sender: mj9ar@gemini.herts.ac.uk X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Sat, 16 Feb 2002 13:39:48 +0000 To: rsgb_lf_group@blacksheep.org From: "James Moritz" <j.r.moritz@herts.ac.uk> Subject: LF: Re: G4JNT "PSK CW" transmission/ Phase display In-reply-to: <002b01c1b6cf$1b826360$af9601d4@g4jnt> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: <majordom@post.thorcom.com> Dear Andy, LF group, I had a few problems with corrupted downloads of Wolf's SpecLab software, so was not able to use it to decode G4JNT's PSK signal last night - however, it was easy to copy the "G4JNT PSK CW"message using the phase transitions visible on the spectrogram as before. While I was hanging around, I thought it would be fun to follow Andy's suggestion and build a breadboard hardware vector display to use with an oscilloscope - unfortunately, Andy had gone QRT by the time it was working, but it was certainly interesting to look at other LF signals in this way. The phase jumps on DCF39 are clearly seen. With a wider bandwidth, you can observe the phase modulation on the Radio 4 198kHz signal. The French station on 162kHz has something similar, but with rather greater phase deviation. Atlantic 252 is a couple of Hz low in frequency, and the phase has a funny little wobble. GBR on 15.98kHz is particularly intriguing and quite hypnotic - the phase of the MSK signal is changing all the time, the symbols appear to be represented by changes in the direction of the phase shift from increasing to decreasing or vice-versa, which occur at fixed points on the phase circle. I'll definitely have to build it up more permanently... Cheers, Jim Moritz 73 de M0BMU