Re: advice needed for weak signals and noise

["jmj050856" <jmj050856@xxxxxxx>]

Hi Keith

Thanks for the very informative response. Things have improved a lot
since I moved the XM10U to a different socket so I'll see how things
go as I continue to add more X10 stuff to my house. I am planning on
adding a lot more wired-in lamp modules and micromodules to transmit
next week so I'll report back afterwards.

Thanks for taking the time to help out. If you ever get around to
testing those filters I'd be very interested to hear how it goes.

Many regards
Joe.

--- In ukha_d@xxxxxxx, "Keith Doxey" <ukha@d...> wrote:
> Hi Joe,
>
> Electrical noise is unlikely to be a problem. Nut the equipment you
list is
> likely to be!
>
> Since the introduction of the EMC regulations several years ago
> manufacturers have had to make equipment that does not chuck noise
out onto
> the mains. The quick and easy fix for this is for them to fit
chokes inline
> with the mains lead.
>
> This stops most interference from entering or leaving the
equipment. Because
> a small amount of noise will still get through, they then fit a
capacitor
> across the Live and Neutral on the mains side of the chokes to
short circuit
> any residual interference.
>
> The filter is very good at stopping the interference from leaving
the
> equipment, but unfortunately a side effect of this is that any
other noise
> on the mains is also killed. In most cases this would be a bonus,
but as X10
> (or any other powerline carrier) is essentially interference that is
> deliberately introduced onto the powerline, it also gets killed or
> attenuated.
>
> The weak signals you describe are exactly that, something further
down the
> powerline is sucking up loads of signal reducing its strength.
>
> The devices you suspect of causing interference are actually the
things that
> are sucking up the signal. Removing them allows X10 signals to
propogate
> successfully so the outward appearance is that you have "removed
the
> interference".
>
> What you need are filters designed to stop interference getting INTO
> equipment. These consist of chokes at the mains side and a
capacitor at the
> equipment side. Fitting these to a distribution board allows to you
to stop
> several devices from killing the signals with a single filter.
>
> Because chokes are quite large and heavy. the filters also tend to
be quite
> large, similar to large plugtop power supplies. Some of
the "Filtered"
> plugboards will actually make matters worse. These do not have the
physical
> space to accomodate the chokes required for proper filtering and
tend to
> only contain Capacitors to short out interference (including the
desired
> X10) and Transient suppressors to remove spikes.
>
> I keep meaning to delve into the depths of my garage where I have
some old
> choke type filters so that I can test them out. They are available
in 3A, 7A
> and 13A versions so could easily filter a whole rack of equipment.
>
> I have just looked at the Farnell website and was shocked to find
out how
> much they actually cost. ( I used to fit hundreds of these!!!!)
The specs
> and prices are listed below...
>
> Filter 	Attenuation
> Rating  	100kHz  1MHz  10MHz
>
> 3A		40dB  70dB  60dB
> 7A  		50dB  50dB  65dB
> 13A  		20dB  50dB  60dB
>
> They are available in two styles, a wireable plug, or a plug in
adapter
>
> 	Adapter Style		Wireable Plug Style
> 3A	150219	32.44		151317	28.36
> 7A  	150220	39.62		151318	32.95
> 13A  	151030	47.61		151319	44.00
>
> As I said, I havent actually tried one to see if it does stop
devices
> killing X10 so please dont rush out and order a load until after I
have been
> rescued from the pile of crap^H^H^H^H stuff that will one day be
useful that
> fills my garage.
>
> Keith
>
> www.diyha.co.uk
> www.kat5.tv
>
>
> > -----Original Message-----
> > From: jmj050856 [mailto:jmj050856@xxxxxxx...]
> >
> > I have recently entered the world of X10 and despite many
frustrated
> > days and nights (I've even resorted to reading the instruction
> > manual) I still can't get things working. I have identified 2
main
> > problems though, so really what I need is some advice on how to
> > correct them.
> >
> > 1) weak signals -
> >
> > 2) electrical noise -