Return-Path: Received: (qmail 8848 invoked from network); 26 Feb 2001 12:46:36 -0000 Received: from unknown (HELO murphys-inbound.servers.plus.net) (212.159.14.225) by 10.226.25.101 with SMTP; 26 Feb 2001 12:46:36 -0000 Received: (qmail 29011 invoked from network); 26 Feb 2001 12:46:35 -0000 Received: from unknown (HELO post.thorcom.com) (212.172.148.70) by murphys with SMTP; 26 Feb 2001 12:46:35 -0000 Received: from majordom by post.thorcom.com with local (Exim 3.16 #2) id 14XMwA-0002y0-00 for rsgb_lf_group-outgoing@blacksheep.org; Mon, 26 Feb 2001 12:39:34 +0000 X-Priority: 3 Received: from d12lmsgate-2.de.ibm.com ([195.212.91.200]) by post.thorcom.com with esmtp (Exim 3.16 #2) id 14XMw9-0002xq-00 for rsgb_lf_group@blacksheep.org; Mon, 26 Feb 2001 12:39:33 +0000 X-MSMail-Priority: Normal Received: from d12relay02.de.ibm.com (d12relay02.de.ibm.com [9.165.215.23]) by d12lmsgate-2.de.ibm.com (1.0.0) with ESMTP id NAA144654 for ; Mon, 26 Feb 2001 13:38:44 +0100 Received: from usa.net (ss10.bld.socks.ibm.com [9.14.4.76]) by d12relay02.de.ibm.com (8.8.8m3/NCO v4.95) with ESMTP id NAA32172 for ; Mon, 26 Feb 2001 13:37:18 +0100 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Message-ID: <3A9A4DF1.1305DE7B@usa.net> Date: Mon, 26 Feb 2001 13:37:05 +0100 From: "Alberto di Bene" Organization: Undisclosed X-Mailer: Mozilla 4.76 [en] (Win95; U) X-Accept-Language: en MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org Subject: LF: Re: 10 sec. dots References: <3.0.1.16.20010226103826.2dcfda92@mail.cc.kuleuven.ac.be> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Rik Strobbe wrote: > Saturday afternoon I was in the shack and had ARGO running (at 3sec/dot) > while being otherwise occupied. at 17.50 I saw a very faint interruped line > on 137701, 'T' copy at best. It seemed 10sec/dot QRSS to me, so I switched > ARGO to 10sec/dot and the faint line became a 'O' copy signal of what > seemed the end of a QSO as I could just copy : 'TNX E E SK'. > Conclusion : 10 sec/dot can make a real difference over 3 sec/dot (from 'T' > to 'O') > Question : who's transmission did I catch ? > > 73, Rik ON7YD At 10s dot the FFT bin size is exactly 1/4 of the size at 3s dot. So, if the noise power is evenly distributed, and the wanted signal falls exactly in a single bin, there is a 6 dB S/N improvement from passing from one mode to the other. How those 6 dB translate into a visual gain is difficult to say, given also the higly non-linear mapping between magnitudes and color saturation in Argo. 73 Alberto I2PHD