Message-ID: <000a01c2e41c$ff227260$fe78a8c0@W1KW>
From: "Holger 'Geri', DK8KW" <holger.kinzel@qru.de>
To: rsgb_lf_group@blacksheep.org
References: <LOBBIDNOENMNHIBGDCKBOEBLDIAA.g3wkl@btinternet.com> <002001c2e406$441ea170$fe78a8c0@W1KW> <002b01c2e40f$5fcb0c20$1b00a8c0@dellboy>
Date: Thu, 6 Mar 2003 21:14:29 +0100
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Subject: LF: Re: Re: Re: LF broadband QRN?
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Hi Dave,

I am not talking about poweline communication as such, but the devices I saw
were kind of small powerline LAN modems for point-to-point communication
within houses, and I am sure those can be pretty nasty if they are getting
popular ...

Vy 73

Geri, DK8KW (W1KW)


----- Original Message -----
From: "Dave Pick" <g3yxm@wireless.org.uk>
To: <rsgb_lf_group@blacksheep.org>
Sent: Thursday, March 06, 2003 7:36 PM
Subject: LF: Re: Re: LF broadband QRN?


>
> Geri.
>
> It's already trialling in Crieff and Campeltown (central Scotland). I
don't
> think it'll be radiating as far as John's QTH though!
> My ADSL via telephone wires causes no problem on any band.
> If there are 50 or 100Hz components it's most likely a PSU.
>
> http://www.hydro.co.uk/broadband/
>
> http://news.bbc.co.uk/1/hi/technology/2754203.stm
>
> Dave
> G3YXM
>
>
>
>
> > Hello John,
> >
> > in a computer-magazine saw a new kind of cable-less modems that work
> through
> > the regular power line. No idea on which frequencies those devices
> operate,
> > hopefully not on 73 or 136 kHz!
> >
> > Geri, DK8KW (W1KW)
> >
> >
> > ----- Original Message -----
> > From: "John W Gould" <g3wkl@btinternet.com>
> > To: "Rsgb_Lf_Group@Blacksheep.Org" <rsgb_lf_group@blacksheep.org>
> > Sent: Thursday, March 06, 2003 1:02 PM
> > Subject: LF: LF broadband QRN?
> >
> >
> > >
> > > Since the 73kHz tests on Tuesday I have been monitoring at several
times
> a
> > > day and find a consistent and steady  noise-level that is about 20dB
> below
> > > the signal at 138.8kHz, and about 6dB below the one at 75kHz. Its a
> mains
> > > type of buzz, beating at times with itself.  Like most I have had this
> in
> > > the past and put it down to RFI from switched-mode PSUs, however, it
was
> > > only sporadic in the past so I am wondering if it's something new.  It
> > seems
> > > to be all the way up the LF band to just below the LW broadcast band
> (but
> > > that cut-off could be a function of my aerial's resonance set at
73kHz).
> > >
> > > The only thoughts that I have is ADSL or signalling on the HV
> underground
> > > cable somewhere beneath my garden. Certainly, ADSL will have become
much
> > > more used locally since I last did an serious listening on LF, but I
> would
> > > have thought the radiation would be fairly low from the balanced
> overhead
> > > telephone lines that are at least 200m from my aerial. I would have
> > thought
> > > that the shielding around underground HV mains cables would be
> sufficient
> > to
> > > stop low-level signaling causing problems.
> > >
> > > I can't see a real reason why TV related interfernce should increase
> near
> > to
> > > my home.  How far away do TV's etc need to be before they cause
> problems,
> > or
> > > is it more caused by the interference conducting itself along the
mains
> > > cabling, etc.
> > >
> > > Any thoughts?
> > >
> > > 73 John, G3WKL
> > >
> > >
> >
> >
> >
> >
>
>
>