X-GM-THRID: 1219399412198223424 X-Gmail-Labels: rsgb lf X-Gmail-Received: 7f1dd767ab2e12f955e2a963e09decc50486a8a5 Delivered-To: daveyxm@gmail.com Received: by 10.78.127.1 with SMTP id z1cs34937huc; Tue, 7 Nov 2006 06:31:41 -0800 (PST) Received: by 10.66.255.7 with SMTP id c7mr9173219ugi.1162909901511; Tue, 07 Nov 2006 06:31:41 -0800 (PST) Return-Path: Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mx.google.com with ESMTP id j2si2607852ugf.2006.11.07.06.31.40; Tue, 07 Nov 2006 06:31:41 -0800 (PST) Received-SPF: neutral (google.com: 193.82.116.20 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1GhRsd-0005sV-Jh for rs_out_1@blacksheep.org; Tue, 07 Nov 2006 14:24:47 +0000 Received: from [193.82.59.130] (helo=relay2.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1GhRsc-0005sM-Ru for rsgb_lf_group@blacksheep.org; Tue, 07 Nov 2006 14:24:46 +0000 Received: from cas-mta2-fe.casema.nl ([83.80.1.24] helo=mta-fe.casema.nl) by relay2.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1GhRsZ-00086X-H3 for rsgb_lf_group@blacksheep.org; Tue, 07 Nov 2006 14:24:46 +0000 Received: from localhost (cas-filter2.mgmt.casema.nl [10.42.32.69]) by mta-fe.casema.nl (Postfix) with ESMTP id F2C935120 for ; Tue, 7 Nov 2006 15:24:37 +0100 (CET) Received: from mta-fe.casema.nl ([10.42.32.24]) by localhost (cas-filter2.mgmt.casema.nl [10.42.32.211]) (amavisd-new, port 20024) with ESMTP id 15299-05 for ; Tue, 7 Nov 2006 15:24:37 +0100 (CET) Received: from crazypeecee.casema.nl (535576BB.cable.casema.nl [83.85.118.187]) by mta-fe.casema.nl (Postfix) with ESMTP id B9FE43BBC for ; Tue, 7 Nov 2006 15:24:33 +0100 (CET) Message-Id: <6.1.1.1.2.20061107151228.07979730@mail.casema.nl> X-Sender: dickrollema@casema.nl@mail.casema.nl (Unverified) X-Mailer: QUALCOMM Windows Eudora Version 6.1.1.1 Date: Tue, 07 Nov 2006 15:25:12 +0100 To: LF-Group From: Dick Rollema Mime-Version: 1.0 X-Virus-Scanned: amavisd-new at casema.nl X-Spam-Score: 1.1 (+) X-Spam-Report: autolearn=disabled,AWL=-0.827,DNS_FROM_RFC_ABUSE=0.479,DNS_FROM_RFC_POST=1.44 Subject: LF: DSP-filter for aural CW Content-Type: text/plain; charset="us-ascii"; format=flowed 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 Status: O X-Status: X-Keywords: X-UID: 3735 To All from PA0SE Does someone know whether a DSP filter using the sound card of the computer can be found on the internet , that can filter the audio output of the receiver with an adjustable bandwidth down to, say, 20Hz or so? I use a passive audiofilter between the receiver and the headphones with four tuned circuits. It has a bandwidth of about 25Hz, a centre frequency of 900Hz and a linear phase characteristic to avoid ringing. But perhaps a DSP filter could do even better. 73, Dick, PA0SE JO22GD