Return-Path: Received: from rly-df02.mx.aol.com (rly-df02.mail.aol.com [172.19.156.15]) by air-df01.mail.aol.com (v123.4) with ESMTP id MAILINDF014-5354a17f02e256; Sat, 23 May 2009 08:46:55 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-df02.mx.aol.com (v123.4) with ESMTP id MAILRELAYINDF028-5354a17f02e256; Sat, 23 May 2009 08:46:41 -0400 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1M7qbg-0003jA-Gt for rs_out_1@blacksheep.org; Sat, 23 May 2009 13:45:44 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1M7qbg-0003j1-63 for rsgb_lf_group@blacksheep.org; Sat, 23 May 2009 13:45:44 +0100 Received: from smtp-vbr8.xs4all.nl ([194.109.24.28]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1M7qbd-000530-Pr for rsgb_lf_group@blacksheep.org; Sat, 23 May 2009 13:45:43 +0100 Received: from organisa-c1c456 (ndb.demon.nl [82.161.81.65]) by smtp-vbr8.xs4all.nl (8.13.8/8.13.8) with ESMTP id n4NCja6B055654 for ; Sat, 23 May 2009 14:45:41 +0200 (CEST) (envelope-from roelof@ndb.demon.nl) Date: Sat, 23 May 2009 12:45:29 -0000 To: rsgb_lf_group@blacksheep.org From: "Roelof Bakker" MIME-Version: 1.0 References: <003601c9daf5$0351b960$0301a8c0@mal769a60aa920> <4A17C742.2000603@btconnect.com> <4A17DA30.2020602@btconnect.com> <4A17DCB8.4070302@btconnect.com> Message-ID: In-Reply-To: <4A17DCB8.4070302@btconnect.com> User-Agent: Opera Mail/9.63 (Win32) X-Virus-Scanned: by XS4ALL Virus Scanner X-Karma: unknown: X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: LF/MF REPORTS Content-Type: text/plain; format=flowed; delsp=yes; charset=iso-8859-15 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=0.0 required=5.0 tests=none 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) Hello Richard, It has been found that the brain of a skilled CW operator can simulate a filter as narrow as 50 Hz. The difference in noise power between a 60 Hz and 50 Hz filter is 0.79 dB. So either your FT1000 DSP filter is a bit wider or your brain filter is a bit narrower. For slow morse (10 w.p.m.) it can be advantageous to use a filter as narrow as 10 Hz. This will give a 7 dB better S/N ratio than your brain will provide. With weak signals, this really helps. 73, Roelof Bakker, pa0rdt