Delivered-To: daveyxm@virginmedia.com Received: by 10.50.237.98 with SMTP id vb2csp74440igc; Sun, 19 Jan 2014 05:19:53 -0800 (PST) X-Received: by 10.194.79.131 with SMTP id j3mr9999470wjx.17.1390137592675; Sun, 19 Jan 2014 05:19:52 -0800 (PST) Return-Path: Received: from post.thorcom.com (post.thorcom.com. [195.171.43.25]) by mx.google.com with ESMTP id s13si5837706wiv.5.2014.01.19.05.19.52 for ; Sun, 19 Jan 2014 05:19:52 -0800 (PST) Received-SPF: neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) client-ip=195.171.43.25; Authentication-Results: mx.google.com; spf=neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) smtp.mail=owner-rsgb_lf_group@blacksheep.org Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1W4rpL-00037O-0n for rs_out_1@blacksheep.org; Sun, 19 Jan 2014 12:50:11 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1W4rpK-00037F-GJ for rsgb_lf_group@blacksheep.org; Sun, 19 Jan 2014 12:50:10 +0000 Received: from mout2.freenet.de ([195.4.92.92]) by relay1.thorcom.net with esmtps (UNKNOWN:AES256-GCM-SHA384:256) (Exim 4.77) (envelope-from ) id 1W4rpI-0007I5-O5 for rsgb_lf_group@blacksheep.org; Sun, 19 Jan 2014 12:50:09 +0000 Received: from [195.4.92.141] (helo=mjail1.freenet.de) by mout2.freenet.de with esmtpa (ID dl4yhf@freenet.de) (port 25) (Exim 4.80.1 #4) id 1W4rpH-0006R6-Qx; Sun, 19 Jan 2014 13:50:07 +0100 Received: from localhost ([::1]:57479 helo=mjail1.freenet.de) by mjail1.freenet.de with esmtpa (ID dl4yhf@freenet.de) (Exim 4.80.1 #4) id 1W4rpH-0007Aw-N2; Sun, 19 Jan 2014 13:50:07 +0100 Received: from mx10.freenet.de ([195.4.92.20]:43673) by mjail1.freenet.de with esmtpa (ID dl4yhf@freenet.de) (Exim 4.80.1 #4) id 1W4rn2-0007Tc-IL; Sun, 19 Jan 2014 13:47:48 +0100 Received: from blfd-4db03b5c.pool.mediaways.net ([77.176.59.92]:3342 helo=[192.168.178.21]) by mx10.freenet.de with esmtpsa (ID dl4yhf@freenet.de) (TLSv1:DHE-RSA-CAMELLIA256-SHA:256) (port 465) (Exim 4.80.1 #4) id 1W4rn2-00088q-B7; Sun, 19 Jan 2014 13:47:48 +0100 Message-ID: <52DBC972.8080200@freenet.de> Date: Sun, 19 Jan 2014 13:47:46 +0100 From: wolf_dl4yhf User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:17.0) Gecko/20130620 Thunderbird/17.0.7 MIME-Version: 1.0 To: RSGB LF Group at blacksheep , RSGB LF Group at Yahoo X-Originated-At: 77.176.59.92!3342 X-Spam-Score: -0.5 (/) 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: Greetings all, I took the opportunity yesterday evening (with lots of stations crowded within a few hundred Hertz on MF) to test this ridiculously simple "passive narrow-band audio filter" on air (between RX and headphone) : [...] Content analysis details: (-0.5 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [195.4.92.92 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (dl4yhf[at]freenet.de) -0.5 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain X-Scan-Signature: 0b2d339ae1d48966556dfb6ad64e2bce Subject: LF: 'Ugly weekender' build: passive CW audio filter, used on MF Content-Type: text/plain; charset=ISO-8859-15; format=flowed 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 Greetings all, I took the opportunity yesterday evening (with lots of stations crowded within a few hundred Hertz on MF) to test this ridiculously simple "passive narrow-band audio filter" on air (between RX and headphone) : http://www.qsl.net/dl4yhf/passive_lc_audio_filter/passive_lc_cw_audio_filter.htm (just two LC resonators, one of them adjustable with a 'hex' rotary switch ie 16 different selectable center frequencies). The results were quite stunning, compared with a long FIR filter (implemented in software), this ugly design helped a lot in the QRM / QRN .. less 'ringing' than expected from such a simple circuit. 73, Wolf DL4YHF .