Information About66 Block |
| CATEGORIES ABOUT 66 BLOCK | |
| telephony equipment | |
| local loop | |
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A 66 block (also '''M-Block''') is a type of Punchdown Block used to connect sets of wires in a Telephone system. 66 blocks accept 22 to 26-gauge solid wire. The 25 Pair standard non-split 66 Block contains 50 rows, each with a single clip having four slots. The 25 Pair 'Split 50' 66 Block is the industry standard for easy termination of voice cabling. Each row contains two separate 2-slot clips. 66 blocks can be bought pre-wired with an RJ-21 connector that allows a quick connection to a 25-pair cable. Telephone pairs are connected to the block with a punch-down tool by terminating "tip" on the leftmost slot of one row and "ring" on the leftmost slot of the next lower row. Typically a 25-pair cable coming from the phone company punched-down on the left side of this block in pairs. The right hand-side of the block is wired to the customer premise equipment. Bridging clips are used to connect the two center slots connecting left-hand side of a split block its right-hand side. The bridging clips can be removed for testing the circuit without the customer premise equipment. Currently, 66 blocks are considered legacy products. They are physically large and not suited for data applications above 10 Mbit/s. 'Split 50' 66 blocks are still used as network interface blocks in MDFs because of their bridging clip feature. The newer 110 Blocks are used for data applications. SEE ALSO The 110 Block is a similar device that serves the same purpose. The 25-pair Color Code is used to identify individual pairs within a 25-pair cable. |
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