Rewiring Telephone Sockets

Depends on your integrity & financial involvement.

If it's for you, and assuming you only have one line (number) in, I'd say just carry on regardless (just don't tell BT ).

Having said that, if you have a problem with a broadband connection - they'll ask all sorts of embarassing questions, and you may have to fork out for an "engineer" to put it right. If you're re-wiring anyway, may be easier long-term to get BT to sort it out now.

If it's for letting/multiple occupancy etc., it may be best to sort it now (so engineers don't have to disturb an occupied place to run in extensions from "the" master socket)

I think at one time they may have had two lines and when the second line was dropped they were all turned into extensions, its just a house, no sub-lets. The job is for a friend so I could have access at a later date if there is a problem. I came across it when putting in the new ring & lighting circuits and was tiding things up (spaghetti!!).

I have read the 3^rd bell wire can slow down ADSL / Internet speed (they don't want a main bell & most phones will ring on a two line supply) so the idea was to disconnect that 'aerial' wire & just operate on the 1 twisted pair.

But what is the problem with multiple Masters? They have the surge / lightning capacitor & a resistor ( I believe for line checking; is it that the multiple resistors in parallel gives a low resistance reading?) I was going to put it all neatly in a central connection box (after the BT incoming connection) so extensions could be dropped if they slow down the Internet connection, but I wondered why . Thanks for your reply.

Can't help with the wiring question but, if you're trying to boost the broadband speed the BT iPlate might help.

Thank you for the information;, this adapter effectively cuts the 3rd wire [bell wire] as if this is left connected, as often only 1 of a twisted pair, it will act as an aerial, receiving interference and so causing drop out (slowdown) on the ADSL / Broadband line speed. I have already taken the opportunity to disconnect the 3rd wire; as most modern phones include the capacitor required to turn the AC signal (that is sent in addition to the approx -50V dc) into a local bell ring signal. They have no main bell. I managed to catch a BT engineer working on a box in the street and got a few words of advice: basically the multi Masters as far as BT & Telephone calls are concerned it is not an issue, just ADSL / Broadband connection; best to have a Master on the first connection to the 'drop' / incoming line and disconnect any other extensions - use a wireless / roaming handset instead). Keep the other cables as an internal network! Thank you for your replies.

If you are only using one pair in the cable between sockets (and not the two pairs or pair + 1 wire that is commonly used to link master and slave sockets) and you have modern phones you are unlikely to have a problem.

The BT master socket has two functions:

1. surge protection with a gas arrestor, and
2. provide an anti-tinkle bell circuit

1. Multiple gas arrestors in parallel will do do harm except possible to ADSL due to increased capacitive loading.

2. Anti-tinkle is not needed with modern tone dialling phones. Many phones, even in the UK are basically 2 wire devices and ignore the bell circuit.

The master socket provides a bell circuit via a capacitor and bleed resistor to a third wire in the premises that feed the bells in the phones. This was to ensure that the phone bell would not tinkle when someone was dialling from another extension using the old pulse dialling system (tinkling was normal in most other countries systems but was not considered acceptable here in the UK).

If your cabling has 3 or 4 conductors to each socket you could convert all the sockets to slave by snipping out the three components in each master socket except for the one at the point of entry.

Some UK phones require the extra line to ring so I would not remove the components if you only have one pair unless you have confirmed your phones will work correctly.

Strictly speaking you should isolate the phone wire before doing this due to the voltages involved - but few do. Insulated cutters can prevent shocks in damp circumstances.

It used to be a useful dodge in radio studios to remove the third wire from a phone socket to prevent a phone ringing audibly on air - an external flasher would be used instead. Bodging digital phone systems is a bit more complicated.