Twisted Cable

Discussion in 'Broadband' started by naza, Feb 28, 2007.

  1. naza

    naza Guest

    I am having trouble telling whether that phone cable in my house is
    twisited. Could somebody leave some links to Twisted and untwisted
    phone cable. Also what problems i could have with a Untwisted cable.
    naza, Feb 28, 2007
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  2. naza

    ABC Guest

    Most telephone wiring is twisted. Just look to the individual wires and if
    it's twisted, then there will be pairs of wires twisted round each other.

    An untwisted cable is just that, untwisted.
    ABC, Feb 28, 2007
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  3. naza

    naza Guest

    Also what is the correct way that a 3 way IDC junction box should be
    naza, Feb 28, 2007
  4. naza

    ato_zee Guest

    Not quite - there is the earlier telephone Quad, 4-wires, usually
    in a thin grey or cream sheath, all 4 have a long pitch twist, as
    a bundle. In this case the insulation of the wires is commonly
    solid colour.

    Then there is twisted pair,
    comprising an even number of individual wires, where
    two wires make a pair, with each pair twisted together.
    Colour coding is commonly solid colour + same colour
    with stripe to distinguish both the individual pairs and which
    wire is which in each pair.

    So you can have 4-wires made up as two twisted pairs,
    or 200 wires, laid up as pairs, to make the 100-pair,
    commonly used street or underground distribution
    cable between exchange and street cabinets.
    You can get cables with greater than 100-pairs
    but the world is gradually moving to fibre.

    For phone use there isn't much difference in
    performance between quad and twisted pairs
    the phone still rings and voice quality is
    In a high noise environment (microwaves,
    energy saving lamps, boiler ignition systems,
    Dect and mobile phones, fluorescent lamps,
    power tools) the twist in twisted pair will help,
    but may nor completely eliminate BB interference
    from the above sources.
    The same applies to rwisted pair Ethernet.
    ato_zee, Feb 28, 2007
  5. naza

    Eeyore Guest

    The rate of twist is quite low. It's not readily visible froma casual galnce. In
    fact you'd have to stipa piece of acbelt to bu sure.

    I was under the impression that the cable with the solid colours ( orange blue
    green and white ? ) is untwisted.

    Eeyore, Feb 28, 2007
  6. naza

    kraftee Guest

    it is twisted but not as tightly as the newer cables
    kraftee, Feb 28, 2007
  7. naza

    Eeyore Guest

    Right, so it'll have poorer rejection of RF especially.

    Eeyore, Feb 28, 2007
  8. naza

    m Guest

    The old GPO cable contained blue/orange/green/brown wires.
    The twist/lay of this cable was quite poor and particularly, the
    unbalanced nature made it susceptable to interference and one could not
    be sure the twist was continued up to the joins/sockets.

    I recently cut out a length of this for someone and it made a huge speed

    m, Mar 1, 2007
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