telephone extension

[ColJack]

so I got my new BT line connected back up and need 2 extensions, one to by the TV for the skyHD box soon to be purchased, and one to where the new digital cordless will go.. ( no mains near the BT point.. )

I went to B&Q and got the parts I need...

telephone cable is 4 core, and the sockets say to only connect 2,3,4,and 5 up...

so what are numbers 1 and 6 for then????

 

[MrHumbug]

so what are numbers 1 and 6 for then????

Nothing.

You don't need number 4 either. And if you have broadband you may be better leaving 3 disconnected. 3 is the ringer and isn't needed if you have a microfilter on the other end as that has a ring capacitor built in to it.

 

[bernardgreen]

And if you have broadband you may be better leaving 3 disconnected. 3 is the ringer and isn't needed if you have a microfilter on the other end as that has a ring capacitor built in to it.

True. But micro-filters are a compromise between [1] best circuit configuration and [2] simplest "plug and play" route get the system working with the customer doing the work.

It can be advantagous to take a little trouble to not have to use micro-filters and improve broadband operation. On short lines ( as in distance from house to telephone exchange ) the adverse effect of micro-filters on broadband signal is minimal. But if there is a long line or there are other reasons for reduction of broadband signal along the line then removing micro-filters from the system can noticably improve broad band operation.

My recommendation is to separate the wiring for broad band from the wiring for telephones at the NTE 5. Replacing the front section with a "master" filter module that provides terminals for telephone wiring (filtered) and a socket ( and in some cases also terminals ) for the broad band circuit to the modem removes the need for micro-filters. By separating telephone wiring from broad band wiring the broad band signal is not loaded or other wise affected by telephone operation. ( at least not in the internal wiring )

 

[ColJack]

thanks...

now, is there anywhere I can get a new master socket from?
the front of mine is bowed out at the top where it's been pushed out by scotchlok connectors wedged behind the plastic cover inside..

oh and I have cable internet.. 50Mb ..... so I don't really need to know about filters and such for BT broadband.. ta

 

[wingcoax]

Used to be able to get them from B&Q but not looked lately.

 

[RF Lighting]

Type NTE5 into eBay

 

[dave.m]

http://www.run-it-direct.co.uk/BTsocketNTE5.html

 

[MrHumbug]

bernardgreen

Absolutely agree with what you say about the filtered faceplate and running broadband seperately from voice - it's how I've done it at home

But if I understood it correctly, isn't the reason to leave the ring wire disconnected at all sockets because the wire is unbalanced and can pick up interference that degrades your ADSL signal? Consequently it's more of a problem if you have a lot of internal wiring, rather than dependent on your distance from the exchange.

 

[bernardgreen]

NTE 5 can be obtained from Solwise

http://www.solwise.co.uk/adsl_splitters.htm#NTE5

The filtered face plate splitter ( ADSL separated from phone ) is shown on
http://www.solwise.co.uk/images/adsl-nteface-mid.jpg

Other suppliers do exist

 

[bernardgreen]

isn't the reason to leave the ring wire disconnected at all sockets because the wire is unbalanced and can pick up interference that degrades your ADSL signal?

The capacitor in the master socket connects wire 3 to wire 2 for AC signals. This does cause a degree on un-balance in the twisted pair of wires 2 and 5. On a balanced pair any interference affects both wires equally so in effect is cancelled out. With wire 3 connected there is an parallel route to the line for some of the interference that would otherwise affect wire 2. The result is wire 2 has less interference to carry than wire 5 and the interference on 5 and 2 does not cancel out.

Close to the exchange and the ADSL signal is strong and any interference from an un-balanced 2-5 pair is swamped by the signal. But where the ADSL signal is low due to a long line from the exchange then the interference signals need to be kept as low a possible otherwise they distort or even swamp the ADSL signal.

 

[scrappington]

1 and 6 are not used in a domestic telephone installation.

4 is used on telephone systems with 3

! and 6 are used on specialist telephone systems

 

[Lectrician]

1 and 6 are not used in a domestic telephone installation.

4 is used on telephone systems with 3

! and 6 are used on specialist telephone systems

1 & 6 are often used for DATA on telephone PBX's. Other PBX's use the 3 & 4 as DATA, you must make sure you do not use a master socket with those. 2 & 5 are always the analouge speech pair. Systems that use 1 & 6 are designed for use with master sockets and are usually classed as 'hybrid' systems which can use either a standard SLT telephone (picking up the 2 & 5 plus the 3 ringer via the master cap), or a dedicated featurephone which will use the 2 & 5 for the speech and the 1 & 6 for data for the screen and one touch buttons etc.

 

[ColJack]

while i've got you here, my phone keeps blipping ervery now and then for no reason I can tell..
it does it at random whilst on the hook, and blips a few times sometimes when I hang up...

any ideas?

 

[wingcoax]

All extensions i have fitted were on 2,3 &5 this seems to prevent blipping!

 

[bernardgreen]

Do you have more than one master socket in the system and wire three is connected ?

If you do then check the wiring of pins 2 and 5 between the masters. Ensure that pins 2 are joined together and pins 5 are joined together and not crossed over.

If they are crossed the result is a capacitor across the "bell" in the phone and this can store energy via 470,000 ohm resistor until there is enough energy to "strike" the bell.

Some micro-filters ( those with 3 pins in the lead to the wall socket ) and some modems with ring detect can create this fault.