Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-mg06.r1000.mx.aol.com (Internet Inbound) with ESMTP id 0E4B43800009A; Sat, 12 May 2012 06:12:24 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1ST9Hp-0006Vm-Kz for rs_out_1@blacksheep.org; Sat, 12 May 2012 11:10:53 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1ST9Hp-0006Vd-6z for rsgb_lf_group@blacksheep.org; Sat, 12 May 2012 11:10:53 +0100 Received: from mail-gg0-f171.google.com ([209.85.161.171]) by relay1.thorcom.net with esmtps (TLSv1:RC4-SHA:128) (Exim 4.77) (envelope-from ) id 1ST9Hm-0002VN-Ku for rsgb_lf_group@blacksheep.org; Sat, 12 May 2012 11:10:52 +0100 Received: by ggmi1 with SMTP id i1so161465ggm.16 for ; Sat, 12 May 2012 03:10:48 -0700 (PDT) X-DKIM-Result: Domain=gmail.com Result=Good and Known Domain DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:date:message-id:subject:from:to:content-type; bh=+Iap3i481XZR30e8ZRCAOp+3gC52sykGBhbFmgv/EUM=; b=x0XpbvVGXDMcPt5eq3CXr/4WsruxrVftCg5UNLrxaDMndqIwJkg+2wi7mkXb+PkCsl OmT412qfrVC7YnJN10cf/AvtCti2C0HDsDW9QXuM1TM4kdvMnuEnfpSYjuHdEbVJiFR+ IN/nFAafctKH0wuaOt04QXBSvg2ZzI7X4ALrl/n2YsYhEX0qfk9D92A7DOjWFmJc1boQ vedatj1zZHvbckzPeVu0kQ3pVcU9crM9AIpAIl0qyc8x9BIpupOWEkHy2A6hNH0Dpw9e DReT941Ylknjq1I+Nx5Dgsawq3XZG3khoyywfBKwa60cUQPBD5YkqjOaegE+Nicqm4nq YPqA== MIME-Version: 1.0 Received: by 10.50.10.225 with SMTP id l1mr637648igb.1.1336817448372; Sat, 12 May 2012 03:10:48 -0700 (PDT) Received: by 10.231.60.134 with HTTP; Sat, 12 May 2012 03:10:48 -0700 (PDT) Date: Sat, 12 May 2012 10:10:48 +0000 Message-ID: From: Andy Talbot To: ukmicrowaves@yahoogroups.com, rsgb_lf_group@blacksheep.org, RSGBTech X-Spam-Score: -0.7 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: If you want to experiment with how weak signals (tones and CW) sound in accurately defined level of noise ratio, download the utility below which is still in beta test stage. It allows you to generate either a CW message of your choice, at any speed, or a plain tone. Gaussian noise is added to this at a level determined by the S/N ratio requested. S/N is calculated based on any bandwidth of choice. The output is then applied to a filter whose bandwidth and centre frequency can be arbitrarily chosen. The results are stored as .WAV files Conditions of clipping or too low a generated level are detected and you can adjust the ouput scaling to compensate .WAV files are stored in the same directory the software is run from. [...] Content analysis details: (-0.7 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [209.85.161.171 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (andy.g4jnt[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: 5c335215f1b3de26d890ee84d49616ce Subject: LF: Demonstrating audibility of weak signals - utilty to play with. Content-Type: text/plain; charset=ISO-8859-1 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-global-disposition: G X-AOL-SCOLL-SCORE: 0:2:413755808:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-d021.1 ; domain : gmail.com DKIM : fail x-aol-sid: 3039ac1d60ce4fae37886f71 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none If you want to experiment with how weak signals (tones and CW) sound in accurately defined level of noise ratio, download the utility below which is still in beta test stage. It allows you to generate either a CW message of your choice, at any speed, or a plain tone. Gaussian noise is added to this at a level determined by the S/N ratio requested. S/N is calculated based on any bandwidth of choice. The output is then applied to a filter whose bandwidth and centre frequency can be arbitrarily chosen. The results are stored as .WAV files Conditions of clipping or too low a generated level are detected and you can adjust the ouput scaling to compensate .WAV files are stored in the same directory the software is run from. There are no instructions, user manual or anything else, just the programme itself which I hope is self explanatory http://www.g4jnt.com/DownLoad/SNDemo.exe or, if your browser or nanny-software objects to .EXE files, save http://www.g4jnt.com/DownLoad/SNDemo.eex and change the file type to .EXE I've tested the files generated with Spectran and Gram to make sure the S/N ratios generated look correct, based on the spectrum display; all seem to agree within a dB or two. (Exact figures depend on things like effective bin size due to windowing in the FFT the spectrum analyser) Enjoy Andy G4JNT