Very Old GPO Box Issue

I'm trying to connect a new extension cable directly into a 40 years old GPO box which is the only telephone connection into my house. The GPO wires are orange, white? and green in that order from top middle and bottom. The new cable has 4 wires, black, red, green and yellow.

There is an extension already attached which provides my phone into another room but the wire colours seem just as old. It has orange connected to orange, blue connected to the whitish cable and green attached to green. It has an unconnected brown also.

Can anyone please help? How can I tell which cable gets connected to which? I have tried a few different ways and can connect but my bb speed is reduced to a third of normal.

Thanks

What are you trying to achieve by adding this extension ?

It sounds to me as if the cable you are trying to connect is one of those cheapo 'flat' ones, if so, they are no good to man nor beast.

It doesn't matter too much, as long as the same colours are terminated on the same terminations either end. It sounds as though the incoming cable is a drop wire, the orange will be the A leg, the white the B leg. Green, earth, possibly, if it's as old as you say.

The internal cable sounds correct also.

You *should* just need one pair in your new cable to connect to the orange wires, and one to to blue and white terminations.

What type of GPO box is it ?

I am trying to set up my modem in another room from my existing telephone line. The cable worked ok when plugged into the socket but now the socket is too far away I was hoping to use the main GPO box. I realise it really needs completely renewed but was hoping to run this for a little while.

I don't know the different types of boxes but it is about the size of a box of swan vestas matches with rounded corners, One access screw in the centre with GPO around it.

Ah, so you are trying to tee in before the main telephone socket. That's a no no.

Fit an extension from the existing socket, using a good quality cable.

I had one of those old boxes until very recently

When BT came to fix an issue, the guy removed it and fitted a smaller white box along with a Master Socket

My old box was directly above the front door

You should use CW1308 cable for telephone extensions. What you have sounds like alarm cable or similar.

ALSO VERY IMPORTANT

Ensure it is solid copper and twisted in pairs of 0.5mm

If it doesn't specify solid copper it's probably because it is not. I have purchased CW1308 cable and lost a few meg on download, by ensuring it's 0.5mm solid copper I lose no speed what-so-ever.

I can vouch for this seller personally

http://www.ebay.co.uk/itm/280844666425?ssPageName=ST...

That's for outdoor but they do indoor too.

Also don't attach to this GPO. Wire it into the TEST socket. Otherwise you are 'star wiring' which nobody wants to deliberately install.

According to BT, their connectors accept conductors ranging from 0.4mm to 0.6mm. I've never seen anything but solid copper CW1308.

There is cheap copper coated aluminium CW1308 out there - it claims to meet the spec, but often does not.

I bought a drum of CW1308 last summer, I thought it was cheaper than expected. Then found that it was MAGNETIC... Yup, CCS wire or Copper Coated Steel

I don't mind silver plated copper coated steel coax, where the steel is more for strength and at those frequencies skin effect keeps the signal in the silver, but not for ADSL or VDSL No thanks!

Cheers!