Understanding Telphone cable

[600rob]

I need to get some telephone cable to extend the position of a slave socket that comes off a master.

Can anyone explain what the term 'pair' represents when looking at cable specifications?
For example, i think i need to buy some 3 pair 6 core cable.

At a guess i thought pair might represent there being 3 pairs of insulated cores.

Anyone able to explain and advise on what is most suitable?
Thanks Rob

 

[rsgaz]

explain what the term 'pair' represents when looking at cable specifications?

It means that two wires are twisted together by themselves inside the cable jacket. So a three pair cable has three sets of 2 wires that are twisted together on their own, rather than all 6 wires twisting round each other. (these pairs do all then slowly spiral around each other along the length of the cable)

Whereas, if you look at alarm cable, they are not in 'pairs', all of the wires inside the cable jacket just slowly all spiral around together in a bunch along the length of the cable...

 

[600rob]

Got it. Thanks Gaz

 

[rsgaz]

advise on what is most suitable?

Indoor or outdoor cable run?

 

[600rob]

Indoor or outdoor cable run?

Indoor.

Was thinking something like this

 

[rsgaz]

something like this

Yep, perfect.

You could get away with less pairs, but it's already a very thin cable (4.5mm), so it'll be easier to find clips or staples to fit it properly. Running more pairs now can help in the future if you needed a second line for a fax, or wanted to move your broadband router and split the ADSL signal at the master, etc.

 

[600rob]

Cool. Thanks again

 

[Nozzle]

a fax

I remember reading about those. Didn't they fall out of use with the conclusion of the Industrial Revolution, Circa 1840?

Nozzle

 

[rsgaz]

Didn't they fall out of use

But what if he needs to send a telegram to King George III?

Yes, I know they're outdated, but every business I work in still uses one. It was just an example of why running spare pairs is a good idea to save grief in future.