Return-Path: Received: from mtain-mg09.r1000.mx.aol.com (mtain-mg09.r1000.mx.aol.com [172.29.96.209]) by air-ma09.mail.aol.com (v127_r1.1) with ESMTP id MAILINMA092-b5354bac6942354; Fri, 26 Mar 2010 03:58:58 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-mg09.r1000.mx.aol.com (Internet Inbound) with ESMTP id 2FFDE3800008F; Fri, 26 Mar 2010 03:55:47 -0400 (EDT) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Nv4NC-00054f-RX for rs_out_1@blacksheep.org; Fri, 26 Mar 2010 07:54:30 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Nv4NC-00054W-9G for rsgb_lf_group@blacksheep.org; Fri, 26 Mar 2010 07:54:30 +0000 Received: from mbox2.netikka.net ([213.250.81.203]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Nv4NB-0004QV-Ij for rsgb_lf_group@blacksheep.org; Fri, 26 Mar 2010 07:54:30 +0000 Received: from hupu.netikka.net (hupu [172.16.83.91]) by mbox2-feedback.netikka.net (Postfix) with ESMTP id 82DA021F165 for ; Fri, 26 Mar 2010 09:54:23 +0200 (EET) Received: from imp1.netikka.net (imp1.netikka.net [213.250.85.154]) by hupu.netikka.net (Postfix) with ESMTP id 964834B004F for ; Fri, 26 Mar 2010 09:54:23 +0200 (EET) Received: from localhost (localhost [127.0.0.1]) by imp1.netikka.net (Postfix) with ESMTP id 7C411495B7D for ; Fri, 26 Mar 2010 09:54:23 +0200 (EET) Received: from proxy.wartsila.com (proxy.wartsila.com [194.251.142.28]) by imp.netikka.net (IMP) with HTTP for ; Fri, 26 Mar 2010 09:54:23 +0200 Message-ID: <1269590063.4bac682f78276@imp.netikka.net> Date: Fri, 26 Mar 2010 09:54:23 +0200 From: Paul-Henrik To: rsgb_lf_group@blacksheep.org References: <6C45B4DF9588491088AE7001D9226FB6@JimPC> In-Reply-To: <6C45B4DF9588491088AE7001D9226FB6@JimPC> MIME-Version: 1.0 User-Agent: Internet Messaging Program (IMP) 3.2.6 X-Originating-IP: 194.251.142.28 X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Subject: Re: LF: Re: 500kHz and ADSL 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-sid: 3039ac1d60d14bac6883048f X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) LF Quoting James Moritz : > On receive, it is something of a problem on 500kHz - positioning a loop > antenna within about 10m of the phone wire and modem reveals a high leve= l of > white noise-like QRM. Unplugging the modem makes this dissapear. winding= the > incoming phone wire onto a ferrite core to produce a common-mode choke > yields about 10dB noise reduction. I thought I should comment on this since I have fought the same battle wit= h a very similar experience. I also made a few additional changes that clearly= made a difference as well: 1. Common mode choke at the ADSL modem phone line inlet 2. Common mode choke at the power inlet of the ADSL modem 3. Changed the old 15 metre untwisted, 5-wire in-house telephone cable to= CAT5 (any twisted pair type would probably work) All of the above yielded a noticeable improvement. Improvements were made= in the listed order. Choking off the outgoing ethernet CAT5 from the ADSL modem= did not provide any noticeable improvement. The ADSL modem/router in my case is a Cisco 837. BR Paul-Henrik / OH1LSQ