4 Wire Telephone Extension Question

24 Feb 2008
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United Kingdom

I want to plug my new ADSL2 router (t-link) into an old telephone extension socket upstairs but the socket looked cracked and broken so I've bought Secondardy Surface Extension Socket 2/6A
There are four wires coming from the old extension - orange, orange and white, blue and blue and white.
But I have no idea how to wire these old wires to the new extension.
Can anyone help?

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For the set up that you want, you need to check the wires coming from the master socket. Identify the colours in connection 2 and 5 by opening the master. Connect the corresponding colour wire ends in the extension socket to 2 and 5.

The remaining pair will be in terminals 3(ring wire) and 4(unused) but are best left unconnected.

Alternatively use trial and error (probably blue/blue-white) in 2 and 5 at the extension socket until a phone gives dial tone and works.

You will need a microfilter in all sockets with anything connected a nd your router plugged into the ADSL connection.

(However, this is not the ideal set up and you may find that it does not give you optimum broadband speed. Better cable and a filtered master NTE5 socket would be better.)
Hi –Thanks so much for your advice. I opened up the master socket and I had a BT engineer in recently and he changed the internal wiring to the master socket (which he also changed) and so I now only have two wires going into the master socket – blue and orange going into A&B. There are two spare wires – green and brown.
How does this affect what I have to do? Or does this mean that all other connections will have to be rewired too?
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The A&B connections are to the incoming BT cable. (The other incoming wires in the cable is unused spare pair)
I am not sure what type of master socket you have. In an NT5 the A&B connect to 2&5 on the socket, and you continue those to 2&5 on your extension.
Do you have an NT5, or a junction box that in turn connects to a master socket?
However, essentially, you need to use a pair of wires in your extension cable to connect those A&B connections to 2&5 at your extension.
This may help

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