Return-Path: Received: from rly-dg10.mx.aol.com (rly-dg10.mail.aol.com [172.19.151.94]) by air-dg08.mail.aol.com (v121_r5.5) with ESMTP id MAILINDG081-5fc4951c33334d; Wed, 24 Dec 2008 00:06:09 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-dg10.mx.aol.com (v121_r4.4) with ESMTP id MAILRELAYINDG107-5fc4951c33334d; Wed, 24 Dec 2008 00:05:57 -0500 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1LFLw9-0001M0-Td for rs_out_1@blacksheep.org; Wed, 24 Dec 2008 05:05:37 +0000 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1LFLw9-0001Lq-71 for rsgb_lf_group@blacksheep.org; Wed, 24 Dec 2008 05:05:37 +0000 Received: from outbound03.telus.net ([199.185.220.222]) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1LFLw7-0000kq-RP for rsgb_lf_group@blacksheep.org; Wed, 24 Dec 2008 05:05:37 +0000 Received: from priv-edtnaa07.telusplanet.net ([75.157.132.237]) by priv-edtnes29.telusplanet.net (InterMail vM.7.08.04.00 201-2186-134-20080326) with ESMTP id <20081224045930.CNJW3234.priv-edtnes29.telusplanet.net@priv-edtnaa07.telusplanet.net> for ; Tue, 23 Dec 2008 21:59:30 -0700 Received: from [192.168.1.66] (d75-157-132-237.bchsia.telus.net [75.157.132.237]) by priv-edtnaa07.telusplanet.net (BorderWare Security Platform) with ESMTP id F2480912340E63E4 for ; Tue, 23 Dec 2008 22:00:33 -0700 (MST) Message-ID: <4951C1F1.3040101@telus.net> Date: Tue, 23 Dec 2008 21:00:33 -0800 From: Scott Tilley User-Agent: Thunderbird 2.0.0.18 (Windows/20081105) MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <008c01c9652f$5e5d4950$0301a8c0@mal769a60aa920> In-Reply-To: <008c01c9652f$5e5d4950$0301a8c0@mal769a60aa920> X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: wspr Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.9 required=5.0 tests=FROM_ENDS_IN_NUMS 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-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) If you could read you would do some research at K1JT's wonderful website: http://www.physics.princeton.edu/pulsar/K1JT/ Joe has laboured for many a year on similar projects and has written much about his application of the art. What you will find is that research into communication theory that started with CW has taken us here... To answer your specific question the filtering is done in software. The DSP is done in your PC, thereby making filtering in the radio somewhat redundant unless you have strong neighbours in the passband. So using a wide SSB filter and the radio in USB makes for easy math in ones head. Yes, we digital types use our heads from time to time. Often with modes like JT65 used on EME and now quite popular on HF one wants as much bandwidth as possible in the receiver so you can monitor up to the entire band in real time. So lots of raw bandwidth into the computer is a good thing... All BS aside, you may find the technology very interesting to study and you may find that what you discover is that the spirit of the CW operator of old is alive and well just evolving with the times. CW will never die as it has a rich history but it shouldn't be allowed to impede the growth of new modes and technology. You should build yourself a Softrock SDR receiver or even a small transceiver kit and witness a true revolution in radio technology. My little 40/30m rig allows me to watch the entire band of either in real time. With some new software you can monitor all of the CW QSOs at once... Pretty cool. Not to mention you can plug a key into the little box and do what you love most and work'm. 73 Scott VE7TIL mal hamilton wrote: > If recent published info is correct, this specifies a bandwidth of 6hz > why is USB with a bandwidth of 3 khz necessary to receive this > transmission. > Surely it would be obvious that CW mode was more appropriate where > one could use a narrow filter and dsp processor of a few hertz. > I have asked this question before but never got an answer. > g3kev >