I have both BT and Talktalk broadband on two seperate phone BT lines with the copper wires going into the same pole and to the same exchange about 3 miles away.
The S/N figures for the two lines are completely different:
BT Up 6.3db Down 5.2db
Talktalk Up 11.1db Down 11.6db
Is this likely to be down to the quality of the respective ISPs equipment in the exchange or some problem with the copper on one of the lines (the BT one)?
no two pairs of copper are the same and the difference in noise margin is very little from your figures
Sorry chaps I think you are missing the point of my question
BT = 6.3db Talktalk 11.1db
I know it is a long time since I went to school and did logs but I think in absolute terms this is a factor of 3
like webby I misread your post sorry
then problwem is as john46 suggests