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Cat 3 and Cat 5/5E/6 UTP Termination

Cat 3 UTP Termination - Terminating 66 Punchdown Blocks - Part 1


Step 1 NEXT BACK  Examining Cat 3 66 Punchdown Blocks

You will need:

Cat 3 cable

66 Punchdown Block

Punchdown tool with 66 blade


 Lesson Plan Links

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Cat 5 - 110 Punchdown Block

Cat 5 - Jack

Cat 3 - 66 Punchdown Block

Cat 3 - Jack

Cat 3 & Cat 5 - Plug

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The 66 Punchdown block (2) can be used to interconnect patch panels (1) and work area outlets (4). While Cat 5 versions are available, they are generally used with telephones and Cat 3 cables.


The 66 block consists of 50 rows of 4 punchdown contacts, designed for 50 pair backbone cable. On each row, two contacts on either side are connected, allowing for interconnection flexibility. Incoming cables are punched down in the outer IDC contacts.

The 66 block can be terminated with two cables placed across from each other and the interconnection made by a bridging clip. If the cables are not opposite, the interconnection can be made by using wires punched down into the corresponding inner IDC contacts.


 Another high density way to terminate telephone cables with a 66 block is to terminate one cable on the outside contact and the other cable on the inside contact, using each row for two interconnections.


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