how to connect a portable telephone (Test Set) to punch down panel

Posted on 2009-12-16
Last Modified: 2013-12-29
I have a portable telphone (test set) that I need to connect to a punch down panel to find a telephone number.  Does anyone know the procedures to clamp a test set onto a punch down panel to get a dial tone?  
Question by:RaffaeleScotti
    LVL 10

    Accepted Solution

    Goodness we are old school.

    I assume we have a butt set with two clamps.

    1st: Verify that the line is in fact a POTS (plain old telephone service) line. If it is a 6 wire ISDN line you may break your test set if you accidentally connect to the power line. If it is a 4 wire isdn line it won't work. If it is a t-1 line you will disrupt service. And it wont work.

    - A regular phone line, the kind that you can use a butt set with,  has 1 working pair of copper per active line. The cables to the phones usually have two pairs,  one of which is unused unless it is a two line phone.

    The color code for the punchdown block is as shown on this page.

    Basically you want to identify the correct pair, and connect one end of the data set to the first pin in a pair, and connect the other clamp to the other pair. The black goes on tip, red goes on ring, but actually you get dial tone if they are reversed. If the butt set has a polarity tester the led will tell you if it is backwards.
    LVL 12

    Expert Comment

    If its a 66 type block, just clamp on the pins like lanboyo says above.
    If it's a 110 or bix block, you need an adapter, or in a pinch you can clamp your test set leads to 2 unwound paperclips and stick them into the 110 block.
    Obviously, caution should be taken like lanboyo says above, if you do that to a T1 line, down she goes.  Dragging the paperclip across other circuits on the block will also cause service disruption, so a steady hand is necessary.
    Below are little pix of what a 66 block looks like and what a 110 block looks like


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