Whats a loop fault.

Just had BT Wholesale on the phone trying to get my margin reset from 15db to 6db and the BT engineer identified a 'loop' fault on the line. After disconnecting extensions, phones and filters we eventually tracked it down to a Binatone phone - this was all done remotely.

So what's a loop fault ?

A short circuit i.e the 2 wires that make the circuit are in contact with each other.

Thanks for that but the phone still works so could it be the resistance of the phone is too low causing a loop fault ? It is a very old poor quality phone.

Not all loop faults are equal, i.e. a full loop, high resistance loop or a rectified loop.
Did it resolve the SNR problem?

Edited by deleted (Sat 28-Oct-06 19:22:21)

Well I'm not sure it was the cause but my margin is now 6db and getting full sync 8128. The Engineer seemed to want to isolate the loop fault before increasing the target margin. In simple terms I don't know but it seems fixed but I suspect the Engineer wanted to sort out the loop fault before changing the margin ie getting everything squeaky clean before raising the target. She tested the line a couple of times with the phone connected and disconnected and I got back to the computer and it was sync'ing at 8128.

"The Engineer seemed to want to isolate the loop fault before increasing the target margin"
Makes sense to me.

Yep, because if you get the target dropped/reset, and the same fault it was raised for is apparent, then back up it will go. Also, if dealing with the 'powers that be', as you have to to get these things changed, then the line must be testing squeaky clean before they will deal....same for card faults in the exchange, no amount of pleading is going to make them lift and shift it whilst thers a trace of battery on the line.