Return-Path: <owner-rsgb_lf_group@blacksheep.org> Received: (qmail 2902 invoked from network); 3 Nov 2004 11:28:06 -0000 Received: from unknown (HELO ptb-spamcore02.plus.net) (192.168.71.3) by ptb-mailstore01.plus.net with SMTP; 3 Nov 2004 11:28:06 -0000 Received: from mailnull by ptb-spamcore02.plus.net with spamcore-l-b (Exim 4.32; FreeBSD) id 1CPJJX-000NDl-5m for dave@picks.force9.co.uk; Wed, 03 Nov 2004 11:28:31 +0000 Received: from [192.168.67.2] (helo=ptb-mxcore02.plus.net) by ptb-spamcore02.plus.net with esmtp (Exim 4.32; FreeBSD) id 1CPJJX-000NDi-0z for dave@picks.force9.co.uk; Wed, 03 Nov 2004 11:28:31 +0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore02.plus.net with esmtp (Exim) id 1CPJJ7-000LOf-16 for dave@picks.force9.co.uk; Wed, 03 Nov 2004 11:28:05 +0000 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1CPJIb-00026q-8U for rs_out_1@blacksheep.org; Wed, 03 Nov 2004 11:27:33 +0000 Received: from [193.82.116.30] (helo=relay.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1CPJIa-00026h-Sx for rsgb_lf_group@blacksheep.org; Wed, 03 Nov 2004 11:27:32 +0000 Received: from one.surfree.co.uk ([195.80.0.234]) by relay.thorcom.net with esmtp (Exim 4.41) id 1CPJIU-0007Tb-2L for rsgb_lf_group@blacksheep.org; Wed, 03 Nov 2004 11:27:32 +0000 Received: from standalone ([212.248.140.4]) by one.surfree.co.uk (8.9.3/8.9.3) with SMTP id MAA11552 for <rsgb_lf_group@blacksheep.org>; Wed, 3 Nov 2004 12:23:43 GMT Received: by localhost with Microsoft MAPI; Wed, 3 Nov 2004 11:25:31 -0000 Message-ID: <01C4C197.D3FECC50.actalbot@southsurf.com> From: Andy <actalbot@southsurf.com> To: "'rsgb_lf_group@blacksheep.org'" <rsgb_lf_group@blacksheep.org> Date: Wed, 3 Nov 2004 11:25:30 -0000 Importance: high X-Priority: 1 (Highest) Organization: UKNWN(UK) X-Mailer: Microsoft Internet E-mail/MAPI - 8.0.0.4211 MIME-Version: 1.0 X-SPF-Result: relay.thorcom.net: 195.80.0.234 is neither permitted nor denied by domain of southsurf.com X-Spam-Score: 0.6 (/) X-Spam-Report: autolearn=no,RCVD_IN_SORBS=0.1,X_PRIORITY_HIGH=0.516 Subject: RE: LF: Rugby Loran station Content-Type: text/plain; charset=us-ascii; 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=0.5 required=5.0 tests=X_PRIORITY_HIGH 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-Spam-Filtered: by PlusNet SpamCORE (v3.00) For a dot lasting an hour, followed by a space lasting an hour and then repeated, the total power is 50 Watts, with 25W in the carrier, and the rest in the entire set of sidebands stretching out to infinite frequency each side (negative frequencies included which just wrap round) and the sidebands spaced apart by 0.0001389Hz. The amplitude roll-off depends on the pulse shaping, but the total energy is contained only in an infinite bandwidth. So if YOU filter out this signal in your Rx, the received power could vary with CW speed as you lose some sideband energy. Andy G4JNT On Wednesday, November 03, 2004 9:52 AM, Mike Dennison [SMTP:mike.dennison@ntlworld.com] wrote: > On 2 Nov 2004 at 20:18, Stewart Nelson wrote: > > > Not true. For example, if you have a 100 watt CW transmitter > > with the key held down, the carrier power is 100 watts. > > Now, what happens when you send a string of dots (50% duty)? > > Your total power out is indeed 50 watts, but only 25 watts > > is in the carrier; the other half is in the keying sidebands > > (if ideal envelope shaping). In general, the carrier power > > is multiplied by the square of the duty cycle. > > But doesn't the lost power depend on the Morse speed? > Are you saying that for a dot lasting an hour, 50% of the > total key down power is taken up by the few milliseconds at > key up/down? > > Mike, G3XDV > ==========