Hi,
I have pretty old wiring (untwisted copper wires). I’ve been told this type of wiring is prone to crosstalk and to reduce this, to use twisted wires.
How much of the line would need to be twisted wires to reduce cross talk significantly? Obviously we can’t change the wiring underground but realistically from the telephone pole to my master socket, if I changed this wiring to twisted pair, would this significantly reduce cross talk? Or even just some of the wire coming into the home, how significantly can this reduce crosstalk?
Crosstalk derives from services being carried by adjacent pairs in a multipair cable. Changing your wiring will have no impact on crosstalk.
If there is a fault in the house wiring though that causes the pair to become unbalanced, won't this make the whole pair unbalanced right back to the cabinet, (or exchange for ADSL), and therefore more susceptible to crosstalk from other pairs once it has joined a multipair cable?
I don't believe so, no. As far as I'm aware, a defect in local wiring shouldn't make the whole circuit susceptible. However, crosstalk is an extremely complex subject.
I could be wrong - it is nearly 40 years since I studied transmission line theory!
Me too, its over 50 years for me 😄