Return-Path: Received: from rly-db09.mx.aol.com (rly-db09.mail.aol.com [172.19.130.84]) by air-db05.mail.aol.com (v124.15) with ESMTP id MAILINDB052-ae54a8b0cd934e; Tue, 18 Aug 2009 16:19:42 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-db09.mx.aol.com (v124.15) with ESMTP id MAILRELAYINDB093-ae54a8b0cd934e; Tue, 18 Aug 2009 16:19:40 -0400 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1MdV8G-0003ae-A6 for rs_out_1@blacksheep.org; Tue, 18 Aug 2009 21:18:12 +0100 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1MdV8F-0003aV-L2 for rsgb_lf_group@blacksheep.org; Tue, 18 Aug 2009 21:18:11 +0100 Received: from mail.gmx.net ([213.165.64.20]) by relay3.thorcom.net with smtp (Exim 4.63) (envelope-from ) id 1MdV88-0003yD-Pa for rsgb_lf_group@blacksheep.org; Tue, 18 Aug 2009 21:18:07 +0100 Received: (qmail 6841 invoked by uid 0); 18 Aug 2009 20:17:58 -0000 Received: from 85.178.78.120 by www116.gmx.net with HTTP; Tue, 18 Aug 2009 22:17:56 +0200 (CEST) Date: Tue, 18 Aug 2009 22:17:56 +0200 From: "Dennis" In-Reply-To: Message-ID: <20090818201756.306460@gmx.net> MIME-Version: 1.0 References: 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: V01U2FsdGVkX18dJXcL4yUdjQ6bLnAIZwQNFpbStEvn9Zty0iwnYE FP8dRMygKvtQITFAfxLeUSkx/qltroUiC2sg== X-GMX-UID: Qjm5coFEPjl+JOvRCDU2cXU7MTE2NQkh X-FuHaFi: 0.57 X-Spam-Score: 0.3 (/) X-Spam-Report: autolearn=disabled,RCVD_IN_NJABL_PROXY=0.327 Content-Type: text/plain; charset="us-ascii" Subject: LF: 500kHz qrg range 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 Hi! For some hours now I'm sitting in front of the computer, modelling a new and of course much much nicer :) preselector-filter for 500kHz. With a 3-inductor nodal capacitor-coupled bandpass, a 12kHz passband seems to be a good tradeoff beetween insertation loss (2-3db), passband ripple (1db) and shape (-24db at 518KHz, -43db at 531kHz). So far I haven't noticed any transmissions below 500.000kHz (SK6RUD) and above abt. 507kHz (Gus' SSB-Tests). So I ask myself and now You :) , would You say it's important to keep the full rx range from 495kHz to 510kHz and pay the price of a worse stopband attenuation, or do You think, it's unlikely to hear any transmission at the band corners? vy73 Dennis -- Jetzt kostenlos herunterladen: Internet Explorer 8 und Mozilla Firefox 3 - sicherer, schneller und einfacher! http://portal.gmx.net/de/go/chbrowser