Return-Path: Received: (qmail 52715 invoked from network); 5 Mar 2005 19:08:31 -0000 Received: from unknown (HELO ptb-spamcore01.plus.net) (192.168.71.1) by ptb-mailstore01.plus.net with SMTP; 5 Mar 2005 19:08:31 -0000 Received: from mailnull by ptb-spamcore01.plus.net with spamcore-l-b (Exim 4.32; FreeBSD) id 1D7efk-000Gwk-OR for dave@picks.force9.co.uk; Sat, 05 Mar 2005 19:10:45 +0000 Received: from [192.168.67.3] (helo=ptb-mxcore03.plus.net) by ptb-spamcore01.plus.net with esmtp (Exim 4.32; FreeBSD) id 1D7efj-000Gwb-RF for dave@picks.force9.co.uk; Sat, 05 Mar 2005 19:10:44 +0000 Received: from post.thorcom.com ([193.82.116.20]) by ptb-mxcore03.plus.net with esmtp (Exim) id 1D7efT-0006X8-PD for dave@picks.force9.co.uk; Sat, 05 Mar 2005 19:10:27 +0000 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1D7ed0-0003hv-2S for rs_out_1@blacksheep.org; Sat, 05 Mar 2005 19:07:54 +0000 Received: from [193.82.116.30] (helo=relay.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1D7ecz-0003hm-JP for rsgb_lf_group@blacksheep.org; Sat, 05 Mar 2005 19:07:53 +0000 Received: from imo-m18.mx.aol.com ([64.12.138.208]) by relay.thorcom.net with esmtp (Exim 4.43) id 1D7ecy-0003xT-4N for rsgb_lf_group@blacksheep.org; Sat, 05 Mar 2005 19:07:53 +0000 Received: from MarkusVester@aol.com by imo-m18.mx.aol.com (mail_out_v37_r3.8.) id l.1b8.e4fa61a (4328) for ; Sat, 5 Mar 2005 14:07:40 -0500 (EST) From: MarkusVester@aol.com Message-ID: <1b8.e4fa61a.2f5b5d7c@aol.com> Date: Sat, 5 Mar 2005 14:07:40 EST To: rsgb_lf_group@blacksheep.org MIME-Version: 1.0 X-Mailer: 8.0 for Windows sub 6104 X-SPF-Result: relay.thorcom.net: domain of aol.com designates 64.12.138.208 as permitted sender X-Spam-Score: 0.5 (/) X-Spam-Report: autolearn=no,HTML_10_20=0.295,HTML_MESSAGE=0.001,NO_REAL_NAME=0.178 Subject: Re: LF: Re: Slow mode comparisons Content-Type: text/html; charset=windows-1252 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Status: No, hits=0.7 required=5.0 tests=HTML_MESSAGE, HTML_TAG_BALANCE_HTML,NO_REAL_NAME 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) Content-transfer-encoding: 8bit Dear LF Noise-Diggers,

Alan said:
> The swap from QRSS3 to QRSS10 is an advantage of about 3dB also.

Alberto said:
> the FFT bin size is 4 times smaller, and this results in an increase of 6 dB of SNR.

My half-penny's worth is that the transmitted energy per symbol is 3.3 times larger, giving exactly 5.23 dB improvement ;-) That's assuming that the FFT bandwidth is somewhere near the optimum (0.3 Hz and 0.1 Hz respectively). I'd go with Alan in that DFCW is more reliable than QRSS, even more so when comparing readability at a given WPM throughput.

Selecting the right symbol time for an opening of limited duration is certainly intricate, as shown by last night's ZL-VA attempt. The peak SNR in Scott's image would probably have allowed higher speed, but how do we know if its going to be "short and strong" or "long and weak" tomorrow?

Funny thing about the delay on this reflector; I got a pile of mail after 14:08 this afternoon.

I wish you success and good luck.

73 de Markus, DF6NM