RE: Interference?

[Keith Doxey]

Hi Nick,

OK, so I will delay finishing your modules whilst I answer your question
:-)

No magic, just proven technology as used in the Broadcast and Pro Audio
industries since the year dot. BALANCED LINE.

Some people seem paranoid about interference from Mains. As long as you use
balanced distribution any interference is picked up equally on each wire.
This gets cancelled out when the signal is converted back to unbalanced at
the distant end.

Even mains wiring is mostly balanced.....or should be. Whatever flows UP
the
live wire should flow DOWN the neutral. EQUAL but OPPOSITE therefore
effective magnetic field generated is NULL.

The one real cause of mainsborne interference would be the way lighting
circuits were wired in the Seventies. Due to a shortage of copper they
abandoned T&E and went for a Live+Earth and a Neutral wire.

L&E went from consumer unit to switch to switch to switch etc
N went from consumer unit to rose to rose to rose etc
L&E from switch to rose.

Lots of wires carrying current with no opposing current flowing to cancel a
magnetic field.

Hope to have news on the IR add on very soon, just getting the initial rush
of KAT5 second run despatched then I will be able to experiemtn more.

Keith

> -----Original Message-----
> From: <a
href="/group/kat5-users/post?postID=1BASEp_7SktZJir4LZyMPB_9P9NvsZ9RqHZerXSVHtNM7Kca_03UguzA8y6zI57lXpIDSBGeIr0Fr3XyUQ">nickt@t...</a>
[mailto:<a
href="/group/kat5-users/post?postID=1BASEp_7SktZJir4LZyMPB_9P9NvsZ9RqHZerXSVHtNM7Kca_03UguzA8y6zI57lXpIDSBGeIr0Fr3XyUQ">nickt@t...</a>]
> Sent: 25 June 2001 13:39
> To: <a
href="/group/kat5-users/post?postID=RwLwtkEsaWaAg2eKNl8mWrI4gkb1Tv3dWD9GsPWaKLzzEEoUlQIiP_hSleTQKhgyRqu6cHjrQB3DppuZ-hOuAv-EIIlC">kat5-users@xxxxxxx</a>
> Subject: Re: [KAT5] Interference?
>
>
> Keith,
>
> I find that interesting - can you describe what KAT5 does to the line
> level signals to transmit them in analogue form and yet not be
> susceptible to mains hum &amp; noise, even with UTP CAT5e cable.
I'd
> assumed you were transmitting digitally. Like Rehan, it's been
> impossible/impractical to avoid parallel runs with mains cables in my
> house and coupled with great expectations there will be a degree of
> scepticism when I wire up and fire up my (shortly to be delivered?)
> KAT5 units for the first time.
>
> On a general note, is proximity to 240v mains cabling likely to
> degrade the network performance significantly for any other (non KAT5)
> applications?
>
> Any news on IR distribution? If it's not possible to superimpose it
> over a KAT5 signal, would it be possible to run it over a separate
> CAT5 cable, or use the unused pairs on partly used CAT5's (say the
> telephone cables)?
>
> All the best
>
> Nick
>
> --- In kat5-users@y..., "Keith Doxey" <kat5users@d...>
wrote:
> > Hi Rehan,
> >
> > KAT5 is totally Analogue
> >
> > During development I deliberately tried to introduce interference
> and
> > failed.
> >
> > I ran a CAT5 cable down 4 floors with it strapped to a 3phase
> 240/415V cable
> > that was carrying in excess of 200Amps. For the remainder of its
> run the
> > CAT5 was in able trays carrying a 6" diameter bundle of
CAT5's that
> were
> > carrying Ethernet, PBX, PSTN and ISDN. Total length of the cable
> run was
> > about 600 feet. No interference whatsoever.
> >
> > Please note I am not advocating that you should install cable in
> such a
> > manner ;-)
> >
> > I also did a demonstration to Mark McCall where I connected a
> portable CD
> > player to one end of the CAT5 cable. By listening to either wire
of
> the pair
> > at the distant end the CD was audible over the desired signal.
The
> output of
> > KAT5 was free from the CD signal.
> >
> > I am not in a position to ship to the States just yet but do have
> global
> > aspirations ;-))
> >
> > Keith
> >
> > -----Original Message-----
> > From: Rehan Khwaja [mailto:rehankhwaja@y...]
> > Sent: 22 June 2001 21:25
> > To: kat5-users@y...
> > Subject: [KAT5] Interference?
> >
> >
> > Hi,
> >
> > I have a few questions.
> >
> > How does the interference of AC power lines for KAT5 compare with
> > that of coax? Am I correct in thinking that the transmission is
> > analog rather than digital? If so, does the fact that the wires
are
> > twisted pair help with interference from the AC?
> >
> > The background to this is that I'm planning to retrofit my house
for
> > audio and possibly video. I don't have a problem with the cost of
> > coax but I've read that you have to be careful not to run them
close
> > to power lines or you pick up AC hum. I don't think that I'm
going
> > to be able to be very careful about where I run the cables,
though,
> > so I'm looking for a more robust solution. Is KAT5 it?
> >
> > BTW, I'm happy to see it "in production" - I remember
reading the
> > plans for it on your website a while ago. Also, will you ship to
> the
> > USA?
> >
> > Thanks,
> > Rehan
> >
> >
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