Telephone cable - which one do I need?
 

Looking to add a couple of extensions - all indoors.

Do I need a 4-core cable (Screwfix quote 18134) or a 6-core cable (quote
17421)?

TIA.

On Thu, 9 Jun 2005 21:51:19 +0100, "JoeJoe" wrote:

Looking to add a couple of extensions - all indoors.

Do I need a 4-core cable (Screwfix quote 18134) or a 6-core cable (quote
17421)?

TIA.

For a normal UK exchange line, 4 core will do. If the price difference
isn't bad, 6 core (3 pair) might be a better idea if the wiring's
difficult to get at, it gives you a spare pair if one goes wrong.
Only terminals 2,3,4 and 5 need to be connected (One of those is the
earth and isn't really needed but its there so why not LOL)
Terminals 1 and 6 are not used on domestic phonelines

HTH

"Chipmunk" wrote in message
...
On Thu, 9 Jun 2005 21:51:19 +0100, "JoeJoe" wrote:

Looking to add a couple of extensions - all indoors.

Do I need a 4-core cable (Screwfix quote 18134) or a 6-core cable (quote
17421)?

TIA.

For a normal UK exchange line, 4 core will do. If the price difference
isn't bad, 6 core (3 pair) might be a better idea if the wiring's
difficult to get at, it gives you a spare pair if one goes wrong.
Only terminals 2,3,4 and 5 need to be connected (One of those is the
earth and isn't really needed but its there so why not LOL)
Terminals 1 and 6 are not used on domestic phonelines

HTH

It does - thanks a lot.

Chipmunk wrote:
On Thu, 9 Jun 2005 21:51:19 +0100, "JoeJoe" wrote:


Looking to add a couple of extensions - all indoors.

Do I need a 4-core cable (Screwfix quote 18134) or a 6-core cable (quote
17421)?

TIA.


For a normal UK exchange line, 4 core will do. If the price difference
isn't bad, 6 core (3 pair) might be a better idea if the wiring's
difficult to get at, it gives you a spare pair if one goes wrong.
Only terminals 2,3,4 and 5 need to be connected (One of those is the
earth and isn't really needed but its there so why not LOL)
Terminals 1 and 6 are not used on domestic phonelines

I'd recommend the 6 core if you can afford the difference (I haven't
checked).

When I wired in our new church building's phone/network cabling I was
pleased 6 core was used (for the phones, CAT5 was used for network).
All the wiring was already done by the builders etc, but my task was to
terminate the ends into a patch panel etc. On one cable, there was a
short on one of the pairs that had been used - wasn't at either end of
the cable, so somewhere in between. Seeing as the building was
practically finished at this point, replacing the cable wasn't really an
option. As there was a spare pair, I just switched to this pair for
this socket and everything worked.

D

On Thu, 9 Jun 2005 21:51:19 +0100, "JoeJoe" wrote:

Do I need a 4-core cable (Screwfix quote 18134) or a 6-core cable (quote
17421)?

May as well use either 4 or 8.

4 is simple and makes your phones work. If you want any more than this,
Cat5 is the thing to go for. 6 core phone is pretty much extinct in the
middle - we're moving away from complex phone extension systems done by
complex wiring, and any "business phones" that needed 6 cores are
superceded by things that want a full network conenction, or at least
cat5 structured cabling.

The main thing to get right is to do phones (pushdown IDC connectors) in
solid core and alarms (screw terminals) with stranded. Use the wrong
typoe of core in the wrong conector and you will have connection
troubles.


--
Cats have nine lives, which is why they rarely post to Usenet.

Do I need a 4-core cable (Screwfix quote 18134) or a 6-core cable (quote
17421)?

I only use Cat5e for telephone wiring. It will run 2 phone lines, 4 if you
cheat. It is much higher quality than standard phone cable and specially
rated for voice as well as network cabling.

Christian.

JoeJoe wrote:
Looking to add a couple of extensions - all indoors.

Do I need a 4-core cable (Screwfix quote 18134) or a 6-core cable (quote
17421)?

TIA.


Consider using Cat5/6 type cable, it's cheap enough. Eventually domestic
phones may be upgradable to IP type devices in the not too distant future.

--
Adrian

Adrian C wrote:
JoeJoe wrote:
Looking to add a couple of extensions - all indoors.

Do I need a 4-core cable (Screwfix quote 18134) or a 6-core cable (quote
17421)?

TIA.


Consider using Cat5/6 type cable, it's cheap enough.

I came to grief recently by assuming cat6 is upward compatible with
cat5. IM(very limited)E cat5 & 6 are possibly equivalent at low
frequency, but not at high.

I bought cat6 at the same price as cat5 would have been, on basis that
hard work is pushing the cable thru & it would provide some future
proofing, whilst using the lower cost cat5 plugs and sockets.

Various web sites (eg clarity.it) suggest you can use a cat 5 cable to
link the front to the back of the house to take normal speech tel
traffic; & to bring the broadband feed from the back where the wireless
router is to the whole-house filter in the BT socket at the front. It
didn't work on the broadband side. However it worked when I replaced
the bb link with ordinary tel cable.

Presume that it has something to do with the hf impedance of the cat6
compared with the cat5. (the term 'image impedance' rings a faint
bell, but that could be a ghost from a long forgotten shady past). dc
testing showed no problem - errors only appeared at broadband
frequencies. Unfortunately I have no hf test gear to be sure.

Looking at the cables in cross section, Cat5 is simply 4 twisted pairs
run touching in a pvc tube, whilst cat6 has a central dividing pvc core
keeping each twisted pair separate. Also I see the Maplin (not,
incidentally, where the cat6 was bought) catalog has various values for
C of cat5, but doesn't specify the capacitance of cat6, so it could be
there's a query on cat6 capacitance matching.