atcomsystems.ca/forum Forums Other TDM Phone Systems 1A2 and Comkey Telephones & Systems ITT 403 MOH practice

I've been looking for one of these for almost two years with no luck. I was poking around ebay and a guy was selling an ITT KSU that he knew nothing about. In the pictures I saw the 403 card. He was asking way too much for an old, untested 1A2 KSU. (Even though we all know it probably is fine.) I sent him a message, offering to buy just the 403 card if the listing ended without a buyer. I knew it would. We went back and forth, agreed on a price, and when the listing ended, we made the deal. After the 403 card was in the mail, I filled him in on what exactly he had, a 501 KSU and a 400E line card, told him what he should list it as, and he was happy as a clam. He got money for a card he thought was worthless, and I got a deal on a pretty rare card. And you all know what a frugal guy I am. I love this old stuff, more than I have money to love it, that's for sure.

Ed, I think the card you are thinking of is the WECO 451 card. It's a 40 pin, 4 inch card that supports 7 CO lines. It has 20 pins front, and 20 pins back. Many are vacant, but it has tip & ring on the CO side of the line cards going in, and tip & ring on the station side of the line cards going in. As I recall, the ring sides are just strapped together on the card and the tip sides go across the isolation transformers. I figured this out when I was in a pinch and needed to get music on to an ITT 400E card. I took the two tip leads from an unused set and connected them to the MOH inputs on the 400E and I had music on hold. I had a 400D card go belly up on me and I didn't have a spare one around that I had modified for bridged ringing. I still can't figure out which component failed on that 400D. I had a 400E die on me and I tracked it to a bad diode. A simple swap and that card was back in action. When I get some time I'll give that dead 400D a good look. I take great pleasure in resurrecting dead electronics.

Resurrecting dead electronics is a lost art.

Good for you!

Sam

So true, Sam. Everything is disposable now. The things people used to have repaired we just throw away and buy another one. Remember the days of the TV repair man. He would actually run tests and diagnose a faulty part and replace only the bad component or -gasp- tube. Nowadays we just pitch the TV and head to Best-buy or Wal-mart for a new one. Even if a set is repaired, its just a matter of throwing a new circuit board at it and hoping that fixes it. That's one of the things I love about 1A2. Every part of the system can be repaired. I've adjusted chaining switches, tuned dtmf pads, rebuilt switch-hook pileups, and even rewired my 501 KSU from scratch. (Someone butchered that poor thing.) It all works just as well as it did in the 1970's or earlier when this stuff was new. My ACS stops working... that's not a free -change a component- fix. It's an expensive processor replacement, or an expensive trip to a refurbisher. -Not my preferred choice.

When I worked for GTE, every Electronic or Digital CO came with an Oscilloscope, a VOM and a Huntron Tracker. You were expected to troubleshoot your problems - and repair them.

The Huntron was a little box, like a mini O-Scope, that showed you a picture of the component you were testing - A good capacitor was a circle or an oval; a bad one had a bubble sticking out of the circle, a good diode was a check, a bad one was a straight line, etc. It also came in a dual screen model, so you could compare two components side by side.

I had one (and used it) for years. After I retired, I gave it away to a former board member - I hope he's still using it.

They used to be available on Amazon, but no more. eBay still has them though, for a variety of prices.

Sam

Sounds like a neat piece of tech. I'll have to look into one.