Showing results for 
Show  only  | Search instead for 
Did you mean: 
Message 11 of 12

Re: BT FTTC with HH5 noise margin decreases gradually until drop out

I will try these suggestions tomorrow.

One other thing to note, I noticed earlier that the A terminal on the master socket is connected to incoming blue wire and B terminal is connected to white. This would appear to be the opposite way around from a typical installation. I used a meter to check if the Voltage was correct, indicating that the connections to the BT drop cable wires may also be swicthed. Terminal A was reading -49V relative to terminal B, which I think confirms it is the wrong way around. I also read that most phones and broadband modems will work with either polarity, so this may be unrelated.

Additionally, there is a mains cable running down the wall parallel to the telephone cable connected to the master socket with about 6-8" separation between the wires. Could that cause interference?

0 Ratings
Distinguished Sage
Distinguished Sage
Message 12 of 12

Re: BT FTTC with HH5 noise margin decreases gradually until drop out

Polarity is not important.

Its going to be a process of elimination to find the cause, starting with everything else disconnected and turned off.

Its unlikely to me the mains cable, especially as you are not using any powerline connectors.

Switched mode power units are another common source of interference.

A decrease in the maximum data rate, is a good indication that there is interference.

0 Ratings