Return-Path: Received: from rly-dc05.mx.aol.com (rly-dc05.mail.aol.com [172.19.136.34]) by air-dc05.mail.aol.com (v124.15) with ESMTP id MAILINDC052-b234a8bf892cc; Wed, 19 Aug 2009 09:05:46 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-dc05.mx.aol.com (v124.15) with ESMTP id MAILRELAYINDC057-b234a8bf892cc; Wed, 19 Aug 2009 09:05:25 -0400 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Mdkpk-0005R2-La for rs_out_1@blacksheep.org; Wed, 19 Aug 2009 14:04:08 +0100 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Mdkpk-0005Qt-8m for rsgb_lf_group@blacksheep.org; Wed, 19 Aug 2009 14:04:08 +0100 Received: from mail.gmx.net ([213.165.64.20]) by relay1.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1Mdkp3-0006g4-BH for rsgb_lf_group@blacksheep.org; Wed, 19 Aug 2009 14:03:26 +0100 Received: (qmail 10769 invoked by uid 0); 19 Aug 2009 13:03:56 -0000 Received: from 85.178.116.27 by www072.gmx.net with HTTP; Wed, 19 Aug 2009 15:03:55 +0200 (CEST) Date: Wed, 19 Aug 2009 15:03:55 +0200 From: "Dennis" In-Reply-To: <4A8B9246.29046.10FABD@dave.davesergeant.com> Message-ID: <20090819130355.252210@gmx.net> MIME-Version: 1.0 References: , <002e01ca2057$32c9a5c0$0900a8c0@AM> <4A8B9246.29046.10FABD@dave.davesergeant.com> To: rsgb_lf_group@blacksheep.org X-Authenticated: #4122078 X-Flags: 0001 X-Mailer: WWW-Mail 6100 (Global Message Exchange) X-Priority: 3 X-Provags-ID: V01U2FsdGVkX18Uu8c9lv0U2zbh0hQ2CybTHqzNkGWYwlfzd9K10x wzQ53L5Scm78c4uT3EVs09dYPAp5AwPBeAgw== X-GMX-UID: Dc25crJRPjl+duvRCDU23F87MTE2NUmM X-FuHaFi: 0.52 X-Karma: unknown: X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Content-Type: text/plain; charset="iso-8859-1" Subject: LF: Re: 500kHz qrg range* THANKS! Content-Transfer-Encoding: 8bit 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 Hi! Thank You all for the many answers :) Amazing to learn more about the 500kHz-Experiment in USA! > Von: "Dave Sergeant" > What puzzles me about this thread is why you need such a narrow receive > filter anyway. Dave, I'm not an hf-engineer. So, at first, it's my plain curiosity to sit some hours and model and change parameters and learn and see and learn, how such a band-filter behaves, at least theoretically. 2. Most of the time there is a terrible broadband noise present in my home location, which blocks everything below 14MHz and even degrades Polskie Radio I on 225kHz and BBC4 198kHz (with the rx loop outside the house in a tree). That's the reason why I did not report any reception on 500kHz in the last weeks. There simply wasn't anything to receive... Although in a few kHz bandwidth this broadband noise of course does not equal the fieldstrengh of a local broadcast station, the broader the filter, the higher the level, unneccesary loading the mixer. 3. I'm playing with some nice mechanichal filters, ex GDR, IF = 200kHz. This puts the LO to 700kHz or 300kHz, and the image either right into the MW broadcast band or directly to the LORAN's 100kHz. So I think it is a good idea to have a good preselection. Think I will go for a maybe even narrower than 12kHz filter, because this would allow tuning "by ear", peaking it lower or higher than the average european 500-505kHz if needed, so nothing lost ;) vy73 Dennis DL6NVC -- Neu: GMX Doppel-FLAT mit Internet-Flatrate + Telefon-Flatrate für nur 19,99 Euro/mtl.!* http://portal.gmx.net/de/go/dsl02