"Grunff" wrote in message
...
I've been told by several people (including a BT engineer) that ADSL can
work on just one wire. Whenever I heard this, I thought "Hmm, really?",
and not thought about it any more.

Only at a pretty poor performance, if you are near the exchange and there is
a lot of capacitance to earth at both ends. ADSL depends on balanced lines
to reject interfering noise, but the error correcting codes also do the same
job so you will get some throughtput anyway.

The ADSL signal works in a series of 4kHz slots from 30kHz up to over 1MHz.
Lower slots can encode up to 10 bits whereas higher slots only usually
manage 1 bit. But on a perfect system with a short piece of wire ADSL can
manage over 8Mbps so getting 1Mbps (if you are actually getting that even)
isn't too arduous.

But are you sure the break isn't in your splitter filter in which case the
ADSL is getting both A and B lines correctly.