The Science Behind Line Noise

I am Trying to tackle quite a complex case of Line noise at work.
Somebody messed up in planning an now we have a huge problem with line
noise. Well what i am trying to find out is what is changed by the
electrical noise that effects the phone siginal and the basic
sciencetific explanation of what happen and how.

In message <(E-Mail Removed) .com>, naza
<(E-Mail Removed)> writes
>I am Trying to tackle quite a complex case of Line noise at work.
>Somebody messed up in planning an now we have a huge problem with line
>noise. Well what i am trying to find out is what is changed by the
>electrical noise that effects the phone siginal and the basic
>sciencetific explanation of what happen and how.
>
http://cm.bell-labs.com/cm/ms/what/s...hannon1948.pdf
--
Peter R Cook

naza wrote:

> I am Trying to tackle quite a complex case of Line noise at work.
> Somebody messed up in planning an now we have a huge problem with line
> noise. Well what i am trying to find out is what is changed by the
> electrical noise that effects the phone siginal and the basic
> sciencetific explanation of what happen and how.

How about explaining some details first ?

Graham

"naza" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) oups.com...
>I am Trying to tackle quite a complex case of Line noise at work.
> Somebody messed up in planning an now we have a huge problem with line
> noise. Well what i am trying to find out is what is changed by the
> electrical noise that effects the phone siginal and the basic
> sciencetific explanation of what happen and how.
>

Rules of thumb:- Noise has a source. Noise is picked up. So, there's 2
ways of fixing it.

1. Reduce it at source. Often the best way. This could involve things
like changing cables, mains filters, adding ferrite rings, different power
supplies, motor suppressors if relevant, even different equipment if no
joy. If it's not your equipment at fault (outside the building) then
balanced common mode RF filters on incoming cables may help.

2 Reduce the pickup. Can be the same fixes as 1. Both 1 and 2 can be
applied though for better results. Possible fixes:- Screen cables with
adhesive copper tape earthed to a good ground, twist cables i.e. normal
internal phone lines aren't usually twisted pairs, using twisted pairs
could make a massive difference (CAT5 is twisted).

If it's a wireless system then good luck!