> I am in the UK and want to make several phone extensions.
>
> QUESTION: I would like to know I this will increase the level of hum.
>
> ISTR UK phones have a transformer and some other components to
> neutralise hum but would that be good enough to prevent hum from a messy
> setup like mine? Some details are below.
>
> -------------------------
>
> In my situation the phone extension wires and the mains wires will run
> close to one other.
>
> There will be about four or five additional extension phone sockets.
>
> And in some phone sockets there will be a loose extension lead of approx
> 3 metres which will be almost ontop of curled mains flex
Much will depend on the power and light wiring method used and the
quality of the cable used to carry your telephone circuits. What do you
mean when you say "flex". I suspect you'll be amused to learn that in
the USA that word is electricians short hand for flexible metallic
conduit. I doubt that United Kingdom "flex" is anything like Flexible
Metallic Conduit a photograph of which can be found at
<
http://www.tradexpro.com/product_catalogs/machinery_electronics/cable_wire/in-co...-->.
The best way to reduce the amount of noise in telephone lines is to use
station cable that has the wire pairs continuously twisted around each
other. In this way any electro magnetic fields that might otherwise
induce an unwanted noise into the circuit is self canceling in the
twisted pair of wires. Even with good quality station cable best
practice is to maintain at least several inches of separation between
the telephone cables and the electrical power and light wiring.
