In article ,
"Christian McArdle" writes:
I'm not sure about the quality issue? It's possible the bell wire might
make a difference on an ADSL setup, but I'd say probably not in a normal
domestic setup.

The problem is that when you run extensions with quality twisted pair cable,
the signal (2+5) is pretty good, with good interference rejection etc. When
you add the bell line, this signal is unipolar and very subject to crosstalk
and interference, which then gets injected back into the signal, causing
problems.

Obviously, with small extensions and a quiet electro-magnetic environment,
this is often not detectable, but it can become quite troublesome if neither
applies.

This is avoided by connecting only 2 and 5, and using master sockets
for all extensions too. If you have multiple phone lines in the same
cable bundle, this is pretty essential or the ring signal on one line
will be quite audiable on other lines. This would only cause problems
with any lines using multiple old phones with real bells and pulse
dialling, where dialing on one phone can cause bells in the other
phones to 'tinkle'.

--
Andrew Gabriel