Return-Path: Received: (qmail 28960 invoked from network); 31 Jan 2001 10:37:22 -0000 Received: from unknown (HELO murphys-inbound.servers.plus.net) (212.159.14.225) by excalibur.plus.net with SMTP; 31 Jan 2001 10:37:22 -0000 Received: (qmail 20444 invoked from network); 31 Jan 2001 10:31:27 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys with SMTP; 31 Jan 2001 10:31:27 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.16 #1) id 14NuR2-0003PI-00 for rsgb_lf_group-outgoing@blacksheep.org; Wed, 31 Jan 2001 10:24:20 +0000 X-Priority: 3 Received: from jazzfm.netcomuk.co.uk ([194.42.248.66]) by post.thorcom.com with esmtp (Exim 3.16 #1) id 14NuQz-0003PB-00 for rsgb_lf_group@blacksheep.org; Wed, 31 Jan 2001 10:24:18 +0000 X-MSMail-Priority: Normal Received: from jazzfm.com [192.168.102.5] by jazzfm.netcomuk.co.uk [127.0.0.1] with SMTP (MDaemon.v2.8.7.5.R) for ; Wed, 31 Jan 2001 10:30:15 +0000 Received: from JazzFM-Message_Server by jazzfm.com with Novell_GroupWise; Wed, 31 Jan 2001 10:23:51 +0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Message-ID: X-Mailer: Novell GroupWise 5.2 Date: Wed, 31 Jan 2001 10:23:17 +0000 From: "Martin Charman" To: rsgb_lf_group@blacksheep.org Subject: Re: LF: CW etc MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 8bit Content-Disposition: inline X-MDaemon-Deliver-To: rsgb_lf_group@blacksheep.org X-Return-Path: Martin@jazzfm.com Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: I was taught that the term CW (Continuous Wave), was coined to differentiate between the 'pure' oscillations generated by valves or HF rotary generators and the quenched or interrupted oscillations generated by spark transmitters? Martin G4FKK >>> Walter Blanchard 31 January 2001 07:51:29 >>> For some reason this didn't seem to make it onto the reflector first time round so here goes again: Recent discussions on "CW" and "Morse" have brought up some interesting points. Does a mode that is only visually recognisable via a machine count as "Morse" , or is it another manifestation of digital modulation? If the effective bandwidths used with QRSS are in the sub-Hertzian range does that make normally-sent "Morse" a wideband mode that should have no place at LF? Consider : "CW" - "continuous wave" - means just that; a steady unbroken unmodulated carrier wave; "N0N" (or "A0" in old money). Morse code is mainly sent by interrupting the carrier so how can it possibly be "CW"? Only amateurs consider "Morse" and "CW" to be synonymous which is a pity because it clouds our thinking. Sending Morse code by interrupting the carrier is designated "A1A" (or "150HA1AAN" for typical ham morse if you want to be pedantic!) - meaning a single carrier amplitude-modulated by a telegraphy signal. Amplitude modulation (on/off keying) always generates sidebands so it is by no means "narrow-band" by modern standards. In fact, the faster Morse is sent the more continuous and wider are the sidebands; the extreme example of a fast interrupted-carrier system is radar pulsing on/off in nanoseconds and look how wideband that is. So, "QRSS", because it switches only slowly and at long intervals is much more entitled to the narrow-band designation than normal Morse and therefore has more entitlement to be in the "narrow-band" segment. Nobody has defined when exactly slowly-sent Morse ceases to be A1A and becomes N0N. Perhaps we shouldn't press the point, we don't have "N0N" in our licenses! And what constitutes a QSO under QRSS conditions? The exchange of information presumably, but what should be the minimum time-lapse between sending and receiving? Seconds? Minutes? Hours? Days? If I send you a letter (or even an email) and you reply days later I have achieved communication with you and the time-lapse is relatively unimportant so why should radio be different? Just perception?. Then, perhaps we should have different categories of contact. An "instant" QSO using "fast" Morse such as we all know and love from HF is quite difficult to do at LF other than at relatively short ranges. To go Transatlantic in this mode will require a very "full" 1 watt plus two very sophisticated Morse ears and a lot of luck and is probably not open to those who don't have the real estate and cash to put up semi-professional antenna farms. Nevertheless we don't begrudge the lucky few who can do so their contest wins on the HF bands so we shouldn't here either. So, one category for "fast" modes with the proviso that they must complete a specified minimum QSO within, say, one minute. Coming down from such heights we get the many who can only put up "small" antennas and will get electrocuted if they try pushing them to 1 watt radiated. Their only hope is visual QRSS so a second category for "slow" modes which would have to complete a QSO within, say, one hour. Please, no arguments about "players" versus "gentlemen" - you might end up in the wrong category! Walter G3JKV.