Telephone Line Advice

[avcctv]

hi all,

'3' is 'bell supress', this was really for pulse dial phones as without it, as you dialed it it would cause a 'jangle' on other handsets. most '2 wire' handsets today don't need it or care about polarity, but some do. so to comply and so keep regulation standards (and i'm very big on that stuff as you all know) you should link the 3 from the master to all the '3's on the slaves.

it used to be called A B & BC (for bell capacitor). if your into pain, get an old pulse dial phone, have fingers in touch with line and dial out, great as a 'lads party' fun, measuring how far each 'contestant' is thrown across the room.

Chubbs old 999 dialer units had exposed large screw down terminals on the pcb's, i learnt real quick to keep my fingers well away from them on test calls. great fun though attatching a legnth of flex, open end's bared and then stuff up leg of unsuspecting trainee's shorts while unit dialing out, i can still hear the screams of many victims.

regs

alan

Conn No.

Usual Cable Colour

Carries

1

N/A

No connection

2

Blue with White Bands

Speech and Ringing

3

Orange with White Bands

Ringing

4

White with Orange Bands

Not used but usually connected for neatness

5

White with Blue Bands

Speech and Ringing

6

N/A

No connection

I was taught many years ago while installing GPT kit that pin 3 was used to generate an incoming call alert on a secondary phone, I guess things could have changed, but thats still how I do it.

[binthere]

I love you all, actually I thought it was just me how reassuring I thought age was creeping up on me and my brain was losing it.

Everything that you all have said is exactly what I was thinking, but how nice it is to know we all think (almost) the same.

Actually I would rather be fishing but it is to cold at the moment.

Thankyou xxxx

[luggsey]

You do not need 3 at all to make it ring

I have fitted over 100 extension sockets, just by using 2 and 5.

Normally Blue/white and blue/white (bt colours)

They have all rung without any 3 connection

This article explains how to wire a UK telephone extension. You are allowed to install extension wiring so long as the connection to the master socket is via a plug, or in the case of the master socket with a detachable lower half, via the connectors on that section. If you decide to connect directly to the master socket or install/replace a master socket you should be aware that you are in breach of your licence to use the phone service and your service provider may charge if they have to come to rectify a fault caused by your efforts (it is rare for them so to do unless you have been really ham fisted). NEVER connect un-approved devices which take power from the mains to the telephone system. Even if you survive the mains on the cabling the poor wireman sitting in a muddy hole some way away trying to find a fault may not.

Master Socket

This is what a typical master socket looks like. You must have one of these at the point at which BT wiring ends and yours begins. Master sockets should not normally be used for extensions.

Extension (Slave) Socket.

All extension sockets are like this. Note absence of ringing capacitor and surge arrrester. The connectors shown are Insulation displacement types (IDC), Extension sockets (especially if bought in DIY sheds) often have screw terminals.

Fixed Upper section

This is the BT supplied NTE5 master socket found in many installations, this particular one is made by Austin Taylor (http://www.austin-taylor.co.uk/). Internally it is functionally similar to the master socket above but the components are protected by a plastic cover.

User removable lower section

When the front screws are removed the complete lower portion of the socket including the IDC connectors for user wiring can be pulled out. They connect to the back plate by means of a fixed plug. The fixed plug is a standard BT plug and socket and allows all the internal wiring to be easily isolated for fault finding. A normal phone can be plugged directly into the socket remaining in the wall to test if the line is OK.

Depends on the type of phone used, the older style phones will need the signal on "3" to work, modern electronic phones can detect the ring signal on the speech pair.

[avcctv]

Depends on the type of phone used, the older style phones will need the signal on "3" to work, modern electronic phones can detect the ring signal on the speech pair.

Does this mean I am now officially old, I didn't realise this??

[Guest]

Most telephone lines to new properties are 2 wire systems 49v wired to terminals 2 and 5 to a master socket, why if we take take a pair off to an extension and use a normal Solwise socket (not master)connected to 2 and 5 does it interfere with other phones connected to the master socket,but does not interfere if another master socket is used with a plug in broadband filter.

Not quite sure what the question is there?

shouldnt the line in connect to AB, then the extensions are wired out through 2 and 5,

Should be. A & B are for BT to connect to, you shouldn't need to touch these.

if you parallel wiring of the incoming pair, im sure you will need another master, as 2 and 5 are after the master circuitry, correct me if im wrong.

Nope, as A & B and 2 & 5 are all paralleled up so connecting to either will work, although you should only connect to 2 & 5 on the lower half of a master socket for extension wiring.

[F111Buster]

Fitting too many master sockets, ie the 1 with capacitor etc attached can as has been said cause problems, you may be able to get away with an extra master but as well as affecting the phone line it causes problems with ADSL on the circuit. The correct and official method, I am ex BT and now a free lance training instructor for BTEC/City&Guilds Structured Cableing, is to use terminals 2/5 for speech 3 for the ring circuit. Yes some brands of telephone work on just a pair but many do not, if you are wiring sockets for a customer then care should be taken to provide a service for what ever equipment is connected. Care and advice should also be given about the number of broadband filters used, to many also has a detrimental effect on the quality of ADSL service and reliability.