atcomsystems.ca/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems cabling question

Hey guys-
I was out on an install today with my dad's work. I noticed some interesting (to me) 25 pair cable punched down. It was not in the standard color order. There were some groups of four pairs, some of five, some half pairs, and yellow/orange & yellow/slate were at the bottom. Am I crazy or is this how 1A2 blocks were wired? Wish I had a pic.

Jeff:

Are you sure that you weren't looking at 5 X 20 pr. 100 pair cable? These were used for Call Director sets where no violet pairs were provided, just the standard color code for the white, red, black and yellow groups. Could that be what you saw? The cables still had 25-pair "fingers" on the station end, but only 20 pairs were wired to them.

No, it was individual 25 pair cables punched down to 66M blocks, 2 per block, and labeled for a 4 line 1A2. The colors in the cable were all the same, just punched down in an order I have never seen before.

About 35 years ago I saw a job done by someone (a sparkie) who had never seen the Telephone Color Code. He invented his own. It was very logical. But it wasn't the color code.

In all fairness I once got some 25 pair Belden Microphone cable to terminate (about 200 runs!). I asked what the color code was and the foreman had no idea. Just do it! So I made up my own color code.

Needless to say it was wrong. Very logical, but wrong.

Sam

Well I suppose anything is possible

IIRC the old ITT Terryphone had a special color code. Some of the pairs were shielded and the bell and buzzer pairs were seperate in the sheath. This cable would have to be mid '70s vintage. I think it had something to do with the talkback intercom capabilities.

Carl

There was a period when it was suggested to wire cables for 10 button sets this way. This allowed all wires for each line to be together. You ended up with pairs for A-A1 split and the Yellow orange and yellow slate pair at the bottom of the block.

It sounds like ntcp maybe right. I've never heard of it being suggested, but I've seen installers doing wackier things.

It was very common to use split 66m blocks and run one x-connect for every two staions and use bridging clips to connect the second set. When we used to put out Northern Telecom Logic sets (that had a slightly different cut down) along with ITT sets, the guys used to try to do all sorts of stuff to make it work (with one xconnect).

When I did a lot of 1A2, if you had a big closet, a lot of times you would work two guys xconnecting. I remember having one guy who could wire KVs but not K-10s. He could only do the equipment side, not the set side. He would have liked having the swaps done for him on the block.

Sam

A car wash near me still has Terryphones hanging on the wall!

I always tell the story of Chuck with my last 1a2 system. He has about 6 or 7 lines, maybe 12-15 phones, and a VOICEPAC 1500 intercom. If it wasn't for the intercom, he "MIGHT" consider getting a new phone system.

When he dials "0" it turns on all trumpets and they can answer back. Not one zone talkback, but ALL ZONE talkback, and there are transducers in the phones. If an employee is near a phone, he can pick it up and talk one-to-one to the paging person.

Since I can't find the print to the Voicepac, and I don't remember how you turn zones on and off in the all page, I'm at a bit of a loss. I've tracked down the successors to the company in OK City, but they are out until Monday of next year.

I just can't get that single digital phone pair to manufacture all of those extra contact closures and resistance to make a conventional key phone work....

Carl