Return-Path: Received: (qmail 1256 invoked from network); 1 Jun 2000 17:05:32 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by bells.core.plus.net.uk with SMTP; 1 Jun 2000 17:05:32 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.02 #1) id 12xYHA-00055w-00 for rsgb_lf_group-outgoing@blacksheep.org; Thu, 01 Jun 2000 17:56:56 +0100 Received: from mserv1a.u-net.net ([195.102.240.34]) by post.thorcom.com with esmtp (Exim 3.02 #1) id 12xYH8-00055r-00 for rsgb_lf_group@blacksheep.org; Thu, 01 Jun 2000 17:56:54 +0100 Received: from rsgb.u-net.com ([195.102.80.225] helo=rsgb.org.uk) by mserv1a.u-net.net with esmtp (Exim 2.10 #63) id 12xYHO-000620-00 for rsgb_lf_group@blacksheep.org; Thu, 1 Jun 2000 17:57:10 +0100 X-Priority: 3 X-MSMail-Priority: Normal Received: from miked by rsgb.org.uk with SMTP (MDaemon.v2.8.7.4.R) for ; Thu, 01 Jun 2000 17:40:31 +0100 From: "Mike Dennison" X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 To: rsgb_lf_group@blacksheep.org Date: Thu, 1 Jun 2000 17:40:28 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 8bit Subject: Re: LF: Slow CW vs. BPSK etc. In-reply-to: <002701bfcbcf$b0c2f9e0$f41a86d4@kevin> X-Mailer: Pegasus Mail for Win32 (v3.11) X-MDaemon-Deliver-To: rsgb_lf_group@blacksheep.org X-Return-Path: miked@mail.rsgbhq Message-ID: Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: G2HDQ wrote: > Apart from the obvious i.e. the various decoders with text output, I would > put software such as Spectran (VY NICE program, by the way!), Spectrogram, > etc. in the "machine modes" category. This is because it takes a wanted > audio signal which is buried in QRM/QRN and therefore indistinguishable, > and translates it into a visual form, separating it from the unwanted > stuff as a discrete trace on a screen. The only part the brain is required > to play in this process is to interpret the trace as letters and numbers - > most of the hard work has been done already. > See my other message. If the only work was to interpret the trace as letters and numbers, it would be trivial for a bit more coding to be included to do just that - and of course 'strong' signals (ie those that are louder than a mere 10db below noise) come into this category. However, it is quite possible to dig much deeper than this by using the brain to work out what is rubbish and what is signal. Most machines are quite incapable of ignoring static and other noise. In the few reports I have read about the various PSK modes, they appear to have similar error rate to CW, which is very impressive for something read by a machine (conventional CW read by a machine is terrible in the presence of QRM), but at sub-noise levels the error rate increases. This is not the case with visual CW modes for the reasons mentioned above. Of course, very low bit rate PSK may well be a different matter, and that is really comparing like for like. Mike, G3XDV (IO91VT) http://www.dennison.demon.co.uk/activity.htm