[geeks] Cat 5 Interference

[Peter Street]

Big Endian boggled at this amazing message:
> 
> >Is it bad to run cat5 in a conduit with a household (110V 15A) power
> >line?
> 
> In the SAME conduit? quite.
> 
> Daniel

I went to a network once in the UK (240V (at that time) 50hz) where they
had wired up 10BaseT UTP, 10BaseT Co-ax, and Cat5 all through the same
conduit as the telephone lines and the power - not a big conduit either.
They had also thrown in some 10m printer parallel cables.  They were
(unsurprisingly) having crosstalk, interference and problems.

I was asked to see why the computers were taking ages to transmit files
on a hybrid 98/NT 4 network - afterall, "It should transmit at least a
meg a second, shouldn't it?".

I spoke to a few people, and it turned out they had terrible telephone
reception, that BT had been unable to fix.  They were calling BT
something rotten.  I took the 'lid' off the conduits, pulled out the
phone cables and immediately they had better reception.

The 'office geek' had wired the system up...  I suppose the moral of the
story is - if you are going to wire 'em together, put a piece of metal
between 'em to damp out the electromagnetic interference.

Peter Street
Web Developer / Manager
LazerFX Productions
www.lazerfx.co.uk (Under Construction)