Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by mtain-dk03.r1000.mx.aol.com (Internet Inbound) with ESMTP id A03653800009A; Fri, 5 Oct 2012 18:06:44 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1TKG1I-0003mC-M4 for rs_out_1@blacksheep.org; Fri, 05 Oct 2012 23:05:20 +0100 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1TKG1I-0003m3-0G for rsgb_lf_group@blacksheep.org; Fri, 05 Oct 2012 23:05:20 +0100 Received: from imr-ma04.mx.aol.com ([64.12.206.42]) by relay1.thorcom.net with esmtp (Exim 4.77) (envelope-from ) id 1TKG1F-0005XA-ST for rsgb_lf_group@blacksheep.org; Fri, 05 Oct 2012 23:05:18 +0100 Received: from mtaout-ma04.r1000.mx.aol.com (mtaout-ma04.r1000.mx.aol.com [172.29.41.4]) by imr-ma04.mx.aol.com (8.14.1/8.14.1) with ESMTP id q95M57dk019823; Fri, 5 Oct 2012 18:05:07 -0400 Received: from White (nrbg-4dbf9d70.pool.mediaWays.net [77.191.157.112]) by mtaout-ma04.r1000.mx.aol.com (MUA/Third Party Client Interface) with ESMTPA id 9405FE0000A6; Fri, 5 Oct 2012 18:05:02 -0400 (EDT) Message-ID: <1BC499DECA9B4773B1022C689D0CBACA@White> From: "Markus Vester" To: Cc: References: <9924c.40f1d9b5.3da0a564@aol.com> Date: Sat, 6 Oct 2012 00:04:58 +0200 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal Importance: Normal X-Mailer: Microsoft Windows Live Mail 12.0.1606 X-MimeOLE: Produced By Microsoft MimeOLE V12.0.1606 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20110426; t=1349474707; bh=X2yhIBODrLS7oNu41RvqmhiTtBJbZ5aBkHoxN2H+UTY=; h=From:To:Subject:Message-ID:Date:MIME-Version:Content-Type; b=cUQaGtoN9YdktFg9OAW0HZPYDG32fr1KQRfWLqxdJIvhaXaiWrTst6UWeWh/amBK+ AsN1lqqsvM64Us/qjLIea7xLsc+yjhmmCm3zGdCFDfuD3h6s8Wcrxbcr+5hBuX7G5a IPWasDMZoDcqRGQdWScZEDXbW37BEn8Fk0ITyJAI= X-AOL-SCOLL-SCORE: 0:2:432352160:93952408 X-AOL-SCOLL-URL_COUNT: 0 X-Spam-Score: -2.1 (--) 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: Dear MF users, please make sure to avoid placing a carrier or beacon very close to the carrier of an NDB. This could severely irritate the direction finder, without the pilot even noticing that interference is present. [...] Content analysis details: (-2.1 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [64.12.206.42 listed in list.dnswl.org] 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (markusvester[at]aol.com) -0.0 SPF_PASS SPF: sender matches SPF record -2.1 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: fb42d311bf65eb51bbb8124890b4f977 Subject: Re: LF: Re: 630m Band Plan - NDB carriers Content-Type: multipart/alternative; boundary="----=_NextPart_000_0008_01CDA356.3911B870" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: ** X-Spam-Status: No, hits=2.2 required=5.0 tests=HTML_30_40,HTML_FONTCOLOR_BLUE, HTML_FONTCOLOR_UNSAFE,HTML_MESSAGE,MAILTO_TO_SPAM_ADDR, MISSING_OUTLOOK_NAME 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-AUTHENTICATION: mtain-dk03.r1000.mx.aol.com ; domain : mx.aol.com DKIM : pass x-aol-sid: 3039ac1db407506f59f43ff1 X-AOL-IP: 195.171.43.25 X-AOL-SPF: domain : blacksheep.org SPF : none Dies ist eine mehrteilige Nachricht im MIME-Format. ------=_NextPart_000_0008_01CDA356.3911B870 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Dear MF users, please make sure to avoid placing a carrier or beacon very close to the = carrier of an NDB. This could severely irritate the direction finder, = without the pilot even noticing that interference is present.=20 For example, consider an amateur sending a long QRSS carrier 0.1 Hz = beside the NDB carrier. Even if he was 20 dB (!) weaker than the NDB, = the superposition of magnetic fields would periodically swing the DF = needle by up to +- 0.1 rad (5.7 degrees) around the correct azimuth = position, once every 10 seconds. Even with low power, such a situation = cannot be ruled out completely. =20 During the discussions with the German flight safety authority = preceeding the MF allocation, we have briefly considered this "coherent = interference" scenario. We assumed that any amateur would carefully = monitor the frequency before commencing a transmission, and stay away at = least several Hz from any audible NDB carrier. Best 73, Markus (DF6NM) From: KKorn42@aol.com Date: Fri, 5 Oct 2012 16:20:10 -0400 To: rsgb_lf_group@blacksheep.org Subject: LF: Re: 630m Band Plan ... - =E2=80=9Cgood idea to have narrow guard bands around existing = aeronautical beacons=E2=80=9D: it is trivial, that other regions in the = world will probably need different such guards. Just to clarify: a pilot = will tune to the frequ (in kHz, no fractions) of a NDB and expects that = the relevant Instrument will show him the direction to that NDB relative = to his AC. He will listen to the ID just to make sure. Hopefully e.g. a = QRSS Station on top will not disturb the instrument? Most probably our = power restrictions will show that this safeguard unnecessary; we = introduced it as an additional good will act. NDBs are a dying species. ... ------=_NextPart_000_0008_01CDA356.3911B870 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Dear MF = users,
 
please make sure to = avoid placing=20 a carrier or beacon very close to the carrier of an NDB. This could = severely irritate the direction finder, without the pilot even noticing = that=20 interference is present.
 
For example, consider = an amateur=20 sending a long QRSS carrier 0.1 Hz beside the NDB carrier. Even = if he=20 was 20 dB (!) weaker than the NDB, the superposition = of magnetic fields would periodically swing the DF = needle by up=20 to +- 0.1 rad (5.7 degrees) around the correct azimuth position,=20 once every 10 seconds. Even with low power, such a = situation=20 cannot be ruled out completely. 
 
During the discussions = with the=20 German flight safety authority preceeding the MF allocation, we have = briefly=20 considered this "coherent interference" scenario. We assumed that = any=20 amateur would carefully monitor the frequency before commencing a = transmission,=20 and stay away at least several Hz from any audible NDB = carrier.
 
Best 73,
Markus = (DF6NM)
 

From: KKorn42@aol.com
Date: Fri, 5 Oct 2012 = 16:20:10=20 -0400
To: rsgb_lf_group@blacksheep.org
Subject: LF: Re: 630m Band=20 Plan
...
- = =E2=80=9Cgood idea to have=20 narrow guard bands around existing aeronautical beacons=E2=80=9D: it is = trivial, that=20 other regions in the world will probably need different such guards. = Just to=20 clarify: a pilot will tune to the frequ (in kHz, no fractions) of a NDB = and=20 expects that the relevant Instrument will show him the direction to that = NDB=20 relative to his AC. He will listen to the ID just to make sure. = Hopefully e.g. a=20 QRSS Station on top will not disturb the instrument? Most probably our = power=20 restrictions will show that this safeguard unnecessary; we introduced it = as an=20 additional good will act. NDBs are a dying species.
...
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