66/110 blocks - newbie question

Seriously newbie ignorant question. If that offends you, read no further.

I'm asking for help in verifying that my basic grasp of 66/110 blocks is corrrect.

A 66 block has metal contacts arranged in 4 columns. The outer pairs of columns are connected across. To connect ("terminate" just doesn't set off the right thoughts in my brain) wires you punch them down on the outer columns. To connect wires in the block horizontally you use small metal clips on the inner columns. To connect them vertically you punch down jumper wires right on top of the original wires.

A 110 block is just a piece of plastic with grooves/receptacles for clips, in two columns or rows. You attach/make ready wires by punching them down into the block. To make electrical contact to the wires available you punch down clips on top of the wires, either with a special tool or with multiple impacts of the simple punchdown tool you used originally. To make any connections between wires in the block, horizontal or vertical, you punch down jumpers on top of the clips.

Thanks for the help.

Reply to
Bob
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Depends on which 66 block you're talking about, as their use is not limited to LANs and single-line voice circuits. They formerly found wide use with the older 1A2 key telephone systems. In fact, usage of 66- series connecting blocks dates back to the 1960's.

The 66M4-25 has 50 rows of six parallel-connected (across each row) clips. The last column of these clips faces the opposite direction of the others.

The one you're most likely to see today is the 66M1-50. These blocks, also known as 'split' type, can accommodate 50 pairs (100 wires total), 25 pairs each side. Although they have four columns, said columns are electrically split right down the middle.

In other words, the first two columns of each row on the left side of the block are electrically parallel with each other. The second two columns of each row on the right side of the block are likewise parallel with each other. HOWEVER -- The rows are NOT electrically connected all the way across unless you install bridging clips to make them so.

66 blocks can only accommodate one wire per clip. However, you can get stack-on widgets with extra clips. I don't recommend these for LAN use, as they can introduce quite an impedance bump. Come to think of it, I wouldn't use 66-blocks for anything above 10Base-T, period.

Yes and no. There are different punch-blades for 66 and 110 blocks. A good-quality punch tool should need no more than one punch per wire, assuming it's held correctly and the block itself is in good shape.

That sounds right. The clips have connecting slots on the front side.

You're most welcome. Are you also aware of the standard telephone cable color code?

Reply to
Dr. Anton T. Squeegee

A 66M1-50, one of the most commonly used, indeed, has 4 rows by 50 pins. The pins are paired 2x2. An M1-25 is 4 rows all wired the same, and B blocks are 6 rows across 3x3 for the 50 and 6 across for the 25.

To connect them vertically you

No. You only get one punch per pin, but you can connect something to the inner pins before you use bridging clips.

Yeah, that's it. A multi-punch tool does a better job of seating the

110C clips, but in a pinch a block of wood or carefully punching both ends with a single tool will work.

Carl Navarro

Reply to
Carl Navarro

In all my years of experinece, I've never seen two wires punched down on a single terminal, except by mistake. If two wires are on a single terminal, one of them will make poor contact and be noisy or intermittent.

[snip]

Reply to
Watson A.Name - "Watt Sun, th

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