Return-Path: Received: from rly-df07.mx.aol.com (rly-df07.mail.aol.com [172.19.156.20]) by air-df03.mail.aol.com (v125.7) with ESMTP id MAILINDF034-5614ad53a1b20e; Tue, 13 Oct 2009 22:40:42 -0400 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by rly-df07.mx.aol.com (v125.7) with ESMTP id MAILRELAYINDF072-5614ad53a1b20e; Tue, 13 Oct 2009 22:40:28 -0400 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1Mxtlo-0004Dl-AI for rs_out_1@blacksheep.org; Wed, 14 Oct 2009 03:39:20 +0100 Received: from [83.244.159.144] (helo=relay3.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1Mxtln-0004Dc-Ki for rsgb_lf_group@blacksheep.org; Wed, 14 Oct 2009 03:39:19 +0100 Received: from blu0-omc1-s6.blu0.hotmail.com ([65.55.116.17]) by relay3.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1Mxtlb-0006JH-4h for rsgb_lf_group@blacksheep.org; Wed, 14 Oct 2009 03:39:09 +0100 Received: from BLU146-W11 ([65.55.116.9]) by blu0-omc1-s6.blu0.hotmail.com with Microsoft SMTPSVC(6.0.3790.3959); Tue, 13 Oct 2009 19:39:01 -0700 Message-ID: X-Originating-IP: [138.32.244.2] From: Laurence BY3A-KL1X China To: Date: Tue, 13 Oct 2009 18:39:00 -0800 Importance: Normal In-Reply-To: <718FE80422504B16B78D4E4488E2F062@JimPC> References: <245132.24289.qm@web28107.mail.ukl.yahoo.com> X-OriginalArrivalTime: 14 Oct 2009 02:39:01.0370 (UTC) FILETIME=[7CE545A0:01CA4C77] X-Spam-Score: 0.9 (/) X-Spam-Report: autolearn=disabled,HTML_10_20=0.945,HTML_MESSAGE=0.001,MIME_HEADER_CTYPE_ONLY=0 Content-Type: multipart/alternative; boundary="_516a5f99-b0a3-4e3e-a952-8dbacb0b9e5c_" Subject: RE: LF: MOFMT ADSL noise X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: * X-Spam-Status: No, hits=1.9 required=5.0 tests=FORGED_HOTMAIL_RCVD, HTML_MESSAGE,MIME_HEADER_CTYPE_ONLY 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 X-Mailer: Unknown (No Version) --_516a5f99-b0a3-4e3e-a952-8dbacb0b9e5c_ Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable I had the same problem on 500 up in KL7 at home. I ended up moving the mod= em to the garage where the telephone line comes out of the ground and keep= ing the ADSL loaded wiring as short as possible - then on the telephone= side of the router I connected up a pair of reasonable quality of seried= ADSL filters outbound for normal telephone wiring in the house. From 20= over noise I cant "see it" now as the big antennae has been chocked off.= I only use wireless around the property so it wasnt an issue. =20 Next job is to choke off the noise from the AC power line coming out of th= e ground - its awful. =20 relates to MTA Palmer Alaska solutions ADSL =20 Laurence KL 1 X =20 > From: james.moritz@btopenworld.com > To: rsgb_lf_group@blacksheep.org > Date: Tue, 13 Oct 2009 23:10:53 +0100 > Subject: Re: LF: MOFMT ADSL noise >=20 > Dear Pete, Paul-Henrik, >=20 > M0FMT wrote: > ....> Well I can only conclude it is ADSL because it is just raising the= =20 > noise floor it is very subtle not really identifiable like say TV LTB,= it's=20 > a mush...> >=20 > I have problems with ADSL on 500kHz at my QTH - it sounds like "white no= ise"=20 > with no audible distinctive features I can detect. The noise can be abou= t=20 > 10 - 20dB over the band noise here over a fairly wide bandwidth in the= MF=20 > range. It does not seem to be a problem at 136k, perhaps because this is= in=20 > the guard band between upstream and downstream ADSL signals. It is easy= to=20 > tell if you are experiencing noise from your own ADSL connection -=20 > disconnect the incoming phone line (probably just unplugging the modem= from=20 > the phone socket will be enough) and there will be a reduction in noise= =20 > level. Unfortunately, there also seems to be a significant level of simi= lar=20 > noise here from other sources, probably my neighbors' ADSL via the overh= ead=20 > phone lines. >=20 > I have had some success with a noise-cancelling arrangement here, where= the=20 > ADSL noise is sampled using a current transformer made by passing the=20 > incoming phone line through a ferrite core, and summed with the signal= from=20 > loop antennas via a variable phase-shifting and gain-adjusting network,= =20 > which is adjusted for a null in the noise. Also, moving the loop around= the=20 > QTH shows some positions are better than others. Actually, life is a bit= =20 > more complicated at this particular QTH, since there also seems to be=20 > wide-band noise originating as very low-level sidebands from the local= =20 > broadcast stations. This requires a second noise-cancelling network to= null=20 > noise from that direction. Also, it was necessary to insert a relay in= =20 > series with the loading coil to disconnect the TX antenna on receive,=20 > otherwise this coupled more noise into the receiving antennas. But when= it=20 > is all adjusted properly, the overall noise level can be reduced in=20 > favourable directions by about 20dB, which is worth doing. >=20 > Cheers, Jim Moritz > 73 de M0BMU=20 >=20 >=20 =20 _________________________________________________________________ Hotmail: Trusted email with Microsoft=92s powerful SPAM protection. http://clk.atdmt.com/GBL/go/177141664/direct/01/=3D --_516a5f99-b0a3-4e3e-a952-8dbacb0b9e5c_ Content-Type: text/html; charset="Windows-1252" Content-Transfer-Encoding: quoted-printable I had the same problem on 500 up in KL7 at home. I ended up moving the&nbs= p;modem to the garage where the telephone line comes out of the ground and= keeping the ADSL loaded wiring as short as possible -  then on the= telephone side of the router  I connected up a pair of reasonab= le quality of seried ADSL filters outbound for normal telephone wirin= g in the house. From 20 over noise I cant "see it" now as= the big antennae has been chocked off. I only use wireless around the pro= perty so it wasnt an issue.
 
Next job is to choke off the noise from the AC power line coming out of th= e ground - its awful.
 
relates to MTA Palmer Alaska solutions ADSL

 
Laurence KL 1 X
 
> From: james.moritz@btopenworld.com
&g= t; To: rsgb_lf_group@blacksheep.org
> Date: Tue, 13 Oct 2009 23:10:5= 3 +0100
> Subject: Re: LF: MOFMT ADSL noise
>
> Dear Pe= te, Paul-Henrik,
>
> M0FMT wrote:
> ....> Well I can= only conclude it is ADSL because it is just raising the
> noise fl= oor it is very subtle not really identifiable like say TV LTB, it's
&g= t; a mush...>
>
> I have problems with ADSL on 500kHz at= my QTH - it sounds like "white noise"
> with no audible distinctiv= e features I can detect. The noise can be about
> 10 - 20dB over th= e band noise here over a fairly wide bandwidth in the MF
> range.= It does not seem to be a problem at 136k, perhaps because this is in
= > the guard band between upstream and downstream ADSL signals. It is ea= sy to
> tell if you are experiencing noise from your own ADSL conne= ction -
> disconnect the incoming phone line (probably just unplugg= ing the modem from
> the phone socket will be enough) and there wil= l be a reduction in noise
> level. Unfortunately, there also seems= to be a significant level of similar
> noise here from other sourc= es, probably my neighbors' ADSL via the overhead
> phone lines.
= >
> I have had some success with a noise-cancelling arrangement= here, where the
> ADSL noise is sampled using a current transforme= r made by passing the
> incoming phone line through a ferrite core,= and summed with the signal from
> loop antennas via a variable pha= se-shifting and gain-adjusting network,
> which is adjusted for a= null in the noise. Also, moving the loop around the
> QTH shows so= me positions are better than others. Actually, life is a bit
> more= complicated at this particular QTH, since there also seems to be
>= wide-band noise originating as very low-level sidebands from the local > broadcast stations. This requires a second noise-cancelling network= to null
> noise from that direction. Also, it was necessary to ins= ert a relay in
> series with the loading coil to disconnect the TX= antenna on receive,
> otherwise this coupled more noise into the= receiving antennas. But when it
> is all adjusted properly, the ov= erall noise level can be reduced in
> favourable directions by abou= t 20dB, which is worth doing.
>
> Cheers, Jim Moritz
>= 73 de M0BMU
>
>

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