66 block question

On all the ones I've ever seen or used:

None of the rows are ever connected to another row.

Sometimes all the columns in one row are connected to each other, and nothing else.

Sometimes half of the columns in one row are connected to each other (and nothing else), and the other half of the columns in that row are connected to each other (and nothing else). This is often called a "split" block. Applying a bridge connector across the middle two columns in a split block turns it into an un-split block.

There are probably some obscure variants lurking in Bell System documents from 1972, but I think pretty much everything you buy new today will be one of the above two.

Matt Roberds

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I have an old analog phone system in my house. All the stations are wired i n parallel to 66 blocks. I use 2 of these punch down blocks in a metal can. The blocks are individually labelled 66B4-25. These vertically mounted blo cks have 50 horizontal rows of punch down terminals arranged 6 terminals to a row. Each of the 50 horizontal rows of 6 are all individually connected together. Don't use bridging clips. This sounds like what you want. Here is a partial picture. Lenny

There are several different type of Type 66 blocks.

- 4 terminals across, all connected together.

- 6 terminals acorss, all connected together.

- 4 terminals across, split in the middle. (most common type)

- 6 terminals across, split in the middle.

- 4 terminals across, with one terminal monopolized by a 25 pair connector. You need bridging clips for the type that's split in the middle.

Ordered? I get them from the scrap yards. Todays phone systems use Type 110 blocks:

(...)

It's one wire per terminal. With a 6 connector block, you have one wire in, and one wire out, leaving you 4 positions for additional wires. Translation... you'll need the 6 position flavor without the split in the middle. Although you can put a bridging clip over the middle terminals with wires attached, I wouldn't because of the risk of cutting the wire. The clips can have sharp edges.

There are tricks to turn the 66/110 blocks into a bus arrangmenet:

Oh yeah, get a 66/110 punchdown tool. Actually, get two as someone is always borrowing mine.

(...)

If you run out of terminals, you can expand the number of available terminals by placing a second Type 66 block next to the first block, and running jumper wires between them. This is a PITA but is much better than trying to cram two or more wires onto a single terminal, which works, for a while, until it becomes loose.

Ugh. That works, but is really ugly and messy.

Drivel: This is a phone room before I cleaned out the wiring: and after: Notice that all the Type 66 blocks are made for 4 terminals. Phone lines on the left, instrument lines on the right.

Good luck.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Jeff, what do you mean by "instrument lines"?

Curiously, Dave

At least I didn't call it a "blower", "POTS box", "horn", or "farspeaker". I could have called the closet and wiring "inside plant".

In my checkered past, telephones were called "instruments". Mote the article titles: I guess I'm showing my age.

Drivel: The differences between telco lingo and the rest of the world was intentional. In the 1950's, Ma Bell was trying to avoid dismemberment because they were becoming a "vertical monopoly" which controlled everything from components (Western Electric) to end user service. In order to prevent this from happening, Ma Bell had to have one part of their vertical monopoly missing and provided by outside vendors. They chose computers, which were originally considered to be unimportant to telephone service. Big mistake as the previous mechanical switches slowly became computerized starting in the late

1960's starting with 1ESS. Ma Bell was forced to camouflage these computers, which resulted in odd names intended to be very different from what was in use in the computer industry. A computer became a "switch" or "billing machine" and so on. This also inspired the difference in layout of a calculator keyboard, and a telphone keypad. This is pure conjecture and probably wrong, but interesting:

Half a century later, I'm still recovering from all this.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

Ah, "stations", "sets"!

And 50 years hence, yet different nomenclature...

A standard 66 M block has 50 rows of 4 columns making for a total of 200 connectors. They do have ones with 6 terminals across, all connected, but that's less common outside of ancient phone systems. I've not seen one in years that was still in use.

Electrically, there are only two columns. The left and right side of the block are split. If you wiggle the outermost connector on any row you'll see it's the same piece of metal as the one directly next to it.

There are two ways to use a 66 block.

1) use it as a way to connect upto 50 pairs (100 conductors) together. The very left and very right terminals are for either the inside or ouside of the wiring and the inner connector are for the opposite side of the wiring. There are no connections across the block. 2) use it as way to connect 25 pairs for 50 conductors, across the entire block. To connect the gap "bridge clips" are used. You'd usually only use the outer terminals in this configuration. This is the more serious way to wire things up.

In your case, if you want to connect 4 or more lines together you'd weave a common conductor in and out of, or across multiple points on the block, the connect into that. That's why 66 termination tools have a cutting side and a non-cutting blade. Never double connect any one connector either.

My 66M block arrived and I discovered clip 1 = clip 2 | clip 3 = clip 4 of row 1, where "=" means electrically connected and "|" means electrically isolated, on row 1. Similarly, row 1 | row 2 | row 3, . . . | row 50. That means that on row 1, column 1 = column 2 | column 3 = column.

My $15 punch down tool arrived but the 66 blade only punches down and cuts. I can do all the cutting, grind the blade off and do all of the weaving.

Since I only need to join 2 cables at 6 pairs to 6 pairs in each of 3 locations, I only need 36 rows, I can use my bandsaw and cut 12 rows each, leaving the last 14 rows to join 4 cables at 6 pairs each using bridge clips.

It doesn't look like I need to strip the wires on this block, since the clips taper down towards the foot.

Any comments?

Thank all of you for your input.

Regards, Jon

Nope. Remove the blade from the tool. The other end should be there without the cutting edge. It's like this:

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

yup, the standard M or split M block.

Any chance the blade flips over for the non-cutting side? Now that you can see the profile of the tool you may be able to fake with it with something else for the the uncut connections. The impact feature (if your tool has it) isn't needed except for cutting the wires. Maybe wrap the busines end with cut up pop can to hide the cutting part so you don't need to grind the tool.

correct. never strip the wire first, but you should be using the proper guage solid wire for these blocks. They're quite tolerant, take a range of wire and are quite reliable like everything the old AT&T came up with.

Each row of 4 clips are electrically connected. I found them at

(non-split 66M block)