Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dl04.r1000.mx.aol.com (Internet Inbound) with ESMTP id 299A83800012D; Wed, 15 Feb 2012 16:52:39 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Rxmlb-0005gZ-0M for rs_out_1@blacksheep.org; Wed, 15 Feb 2012 21:51:59 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Rxmla-0005gP-K2 for rsgb_lf_group@blacksheep.org; Wed, 15 Feb 2012 21:51:58 +0000 Received: from mail-qw0-f50.google.com ([209.85.216.50]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1RxmlW-0006ay-RK for rsgb_lf_group@blacksheep.org; Wed, 15 Feb 2012 21:51:58 +0000 Received: by qabg27 with SMTP id g27so2052994qab.16 for ; Wed, 15 Feb 2012 13:51:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; bh=WGx8PtBVaX4O0U633goJO3kuFN7fgtrOQI6iU/uaIMw=; b=Oljgtq8GrIWTl8Zb89TTy96RmWfnp+EDx11kYyQHJo4cUbqmVcBmNizh6f0cq2s8i1 6kXPB/cq0tL4Vqdr3wrZXJEntHnD5WhE0iN3wQh0cREyW1AsefRqMQcNanwBo/9jETq9 kj9WunKFhy7YKKIKNFk0tGXkQiGwDvcmHoLvk= MIME-Version: 1.0 Received: by 10.229.77.147 with SMTP id g19mr16422271qck.39.1329342709068; Wed, 15 Feb 2012 13:51:49 -0800 (PST) Received: by 10.229.248.6 with HTTP; Wed, 15 Feb 2012 13:51:48 -0800 (PST) In-Reply-To: <002801ccec2a$6b148430$1502a8c0@Clemens04> References: <6C05E5021A484E229E4D20124C3D4AA9@TraceyPC> <002d01cceb30$87c42cc0$0401a8c0@xphd97xgq27nyf> <4F3A8898.40302@xs4all.nl> <7E7DFBB4D102A04DB5ADC88D66628A4A015771@ICTS-S-MBX5.luna.kuleuven.be> <002801ccec2a$6b148430$1502a8c0@Clemens04> Date: Wed, 15 Feb 2012 16:51:48 -0500 Message-ID: From: Warren Ziegler To: rsgb_lf_group@blacksheep.org X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: Re: WRC-12 Approves the New 472-479 kHz Amateur Radio Allocation Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable 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: 0:2:472538240:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-AOL-SCOLL-AUTHENTICATION: mail_rly_antispam_dkim-m255.2 ; domain : gmail.com DKIM : pass x-aol-sid: 3039ac1d4ad24f3c2926585a X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Clemens, NDB receivers that I have seen typically use an AM filter so that you can also use it for DFing with standard medium wave stations, so assume the bandwidth is 6kHz or greater. --=20 73 Warren K2ORS =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 WD2XGJ =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 WD2XSH/23 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 WE2XEB/2 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 WE2XGR/1 On Wed, Feb 15, 2012 at 4:40 PM, Clemens Paul wrote: > Greetings all, > > I wonder what "secondary user on non-interference basis" means in practic= e. > As we know most NDBs are AM modulated with about 1kHz. > Now it would be interesting to know what selectivity/bandwidth DF receive= rs > for NDBs in aeroplanes might have. > Imagine they have 1kHz or even 2kHz (quite possible). > For non interfering such a receiver one would have to stay well without t= hat > BW. > Hence with a few NDBs spread between 422 and 479kHz there would > virtually remain no usable frequency for us amateurs if we wanted to make > 100% sure not to interfere any aeroplanes' beacon reception. > > 73 > Clemens > DL4RAJ > > --=20 73 Warren K2ORS =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 WD2XGJ =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 WD2XSH/23 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 WE2XEB/2 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 WE2XGR/1