atcomsystems.ca/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems Wiring a 551 Western Electric KSU

Hi,
I have a 551 KSU with an 9 line call director style ITT Phone. I would like to wire this KSU to work with the phone. I also purchased a single ended 25 pair cable with a female connector end. Could I use this to wire the KSU? I would like to hook up 2 regular phone lines coming into the house into the KSU so that I could utilize 2 of the 8 lines on the phone. I looked up a wiring diagram for a 1A2 system on wikipedia:
https://upload.wikimedia.org/wikipedia/commons/3/35/25_pair_color_code_chart.svg

I am not sure if I could use this to wire the KSU to the female connector. Also, how would I add the phone lines into the KSU coming from the wall outlet?

Thanks.

"9 line call director style ITT Phone"
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Number on the bottom is 2830, with other following digits for various options? If so, you've got the right type of phone.

You need to browse all thru the 1A2 forum and do a little studying in the past posts. Pretty much everything you need has been covered repeatedly. For us to answer your questions at this point would be frustrating for you and us.

BUT, Welcome to Sundance and stick around, we have a LOT of fun around here. And we WILL answer your questions, but please do browse previous posts first, you'll find most of your answers there.

TCI Library

The wiring diagrams (called "practices" in the trade) are located here and in other collector clubs' on-line libraries.

551 KSU practice

10-button set practices

To answer your immediate questions:

The phone and the KSU are compatible.

You can use the cable you have to connect one telephone to the KSU.

The connection info is (should be) stamped on the 66 block inside the KSU.

The KSU will handle up to 4 CO lines.

You will need to connect the incoming CO lines to the pins marked CO T1 and CO R1, etc.

You will connect the pairs from the cable to the pins on the left side of the block, starting with the first pin, and going down through the 12th pin, using the standard even-count color code. Do not connect anything to the 10th pin.

Do you have an impact tool? Are you conversant with the color code? Do you understand how 1A2 works? Does the KSU have a 118A frequency generator installed?

Unfortunately, 1A2 is not "plug-n-play" like so many other things these days. It is 50 year-old technology, and it has taken people many years to become good installers and maintainers.

Don't get frustrated, but also, don't expect to figure it all out quickly. Try to learn the correct terminology, including lots of acronyms, right off the bat, because we all talk telephony here. It is like English, but very specialized. If you use the wrong term, we will correct you ONCE. After that, be prepared to get ignored by the COTM* who live here.

*(Crusty Old Telephone Men)

First lesson: Call Director® is a trade mark of the AT&T company. What you have is a "10-button" or "9-line & Hold" tel set. They were invented by Bell Labs, and cloned by other makers. AT&T is referred to as "The American Company" by those of us who worked for them. "The Western Company" means Western Electric. "The New York Company" means New York Telephone Company.

After a few years, you'll speak telephone as well as we do.

2830 tel set practice

Click the above link. The one I sent previously only deals with adding a speakerphone to the set.

Sorry for the confusilation.

"After a few years, you'll speak telephone as well as we do."

It's true. Welcome aboard! Fellow 1A2 enthusiast here...

Welcome to this forum! I have within the last year installed a 1A2 system (see my many posts and questions about this). It works reasonably well, I have four desk keysets, an intercom (still haven't gotten around to hooking it up), and a PA amplifier that I need to incorporate into this thing. Along the way, I somehow got a wee bit diverted, and now I am working on restoring a cord board, and have finally made myself certifiable by deciding to build my very own SXS central office. But I still love my old 1A2 setup, and still find myself polishing yet another old keyset telephone shell. Just be aware that as you get along in this endevor of yours, that you might find yourself spending more and more time on e-pay, craigs list and forums (I belong to 4 just for telephony). Then, you will find someone who has something that you need some 200 miles away, and suddenly, you are making monthly road trips in the heat of summer to get yet even more things to work on. Yep, this hobby turns into a full time job with no paycheck. We do get compensated in enjoyment, however.

Best,

Joe

Regarding Arthur's last post: I didn't know you could add a speakerphone to that phone. Thanks! Learn something new every time I get on here.