The master socket is hidden behind something heavy and given that we're happy with the speed we're getting I'll not go to the trouble of trying the test socket unless the object is moved for another good reason.
I saw the line speed at my relative's halve and then recover (most of the way) when the ADSL filter was added then removed and you may be right about the filter itself being faulty. (My limited knowledge in this area was improved, perhaps, just recently by looking at
this resource.) I plan to look at the matter further soon - again maybe introducing a filtered faceplate whether or not an alternative external filter exhibits the same problem - and will start a new thread if I need help or even simply if I gain experience which may be of value to others.
Thanks for your help.
Edited by deleted (Thu 07-Mar-13 01:23:52)