Return-Path: Received: from rly-db08.mx.aol.com (rly-db08.mail.aol.com [172.19.130.83]) by air-db01.mail.aol.com (v124.15) with ESMTP id MAILINDB013-ae14a8b92a0139; Wed, 19 Aug 2009 01:50:32 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-db08.mx.aol.com (v124.15) with ESMTP id MAILRELAYINDB087-ae14a8b92a0139; Wed, 19 Aug 2009 01:50:26 -0400 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Mde2m-0004dz-20 for rs_out_1@blacksheep.org; Wed, 19 Aug 2009 06:49:08 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Mde2l-0004dq-Ee for rsgb_lf_group@blacksheep.org; Wed, 19 Aug 2009 06:49:07 +0100 Received: from moutng.kundenserver.de ([212.227.126.188]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Mde24-0004Ki-6e for rsgb_lf_group@blacksheep.org; Wed, 19 Aug 2009 06:48:25 +0100 Received: from [192.168.1.64] (host86-177-27-138.range86-177.btcentralplus.com [86.177.27.138]) by mrelayeu.kundenserver.de (node=mreu1) with ESMTP (Nemesis) id 0MKv1o-1Mde2Z0Srb-000H7c; Wed, 19 Aug 2009 07:48:55 +0200 From: "Dave Sergeant" To: rsgb_lf_group@blacksheep.org Date: Wed, 19 Aug 2009 06:48:54 +0100 MIME-Version: 1.0 Message-ID: <4A8B9246.29046.10FABD@dave.davesergeant.com> In-reply-to: <002e01ca2057$32c9a5c0$0900a8c0@AM> References: , <002e01ca2057$32c9a5c0$0900a8c0@AM> X-mailer: Pegasus Mail for Windows (4.51) Content-description: Mail message body X-Provags-ID: V01U2FsdGVkX19B5Gt0IDEvlzwLEXtStfKPUEA6Bayie+gJNDo HII3ekm7gCu2eXgB1s4cjHFQm5L1ToNdbG/if6fwyVxzA/RmeX 1L1ie8crYfIgrutTCw2WrsRGBncRbdz X-Karma: unknown: X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: LF: Re: 500kHz qrg range Content-type: text/plain; charset=US-ASCII 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 On 18 Aug 2009 at 23:56, Alan Melia wrote: > However I suspect that the worst problem in Europe might well be 500kHz > exactly, which is 16 times the TV line frequency. I dont think modern > sets radiate so much at this frequency that they used to with CRTs, but > I still have one or two CRT around me. In fact it is 32 times the line frequency - 15.625kHz x 32 =500kHz I do have a weakish carrier there, so that is probably what it is coming from. What puzzles me about this thread is why you need such a narrow receive filter anyway. Blocking/intermod from broadcast stations is often stated as a problem on 500kHz but I get no problems here with my Datong UC1 (which has a tunable preselector but pretty broadband). If it is a problem then presumably a high pass filter passing above (say) 450kHz with a high attenuation below, or a notch at the frequency of a local LW station would surely be the better solution - or a better receive mixer. 73 Dave G3YMC http://www.davesergeant.com