400 Type 1a2 KTU line cards, Western Electric,ITT and other Manufactures 

You've had an amazing telecom career. Appreciate all your videos.

Thank you Phil, very interesting!

This was very interesting. I've never encountered a 1A1 system. The 1A1 H relay must be the equivalent of the L(?) dual coil relay in the 400E card which is in series with the line when hold is depressed. I've used the L relay to make circuits for A-lead signalling and hold from non-1A2 phones and other applications, then used opto-isolators. Nice to see there's others still interested in and using this old but reliable technology.

I have hundreds of these things complete with power supplies, what are they? I know you said they are line cards. But like what use are they for in a modern phone system? I had tons of them on every floor of our 7 story building. I called att and asked wtf are these? They said they have no idea probably some old PBX stuff. So I busted out the butt set and they were clearly still working. However, none of them had dial tone so I started yanking wires and pulling them off the walls.

Anybody need KTU office equipment. All working.

Pretty Good video, Phil. I ahve many of those same cards. In the past, we used the ITT 400E almost exclusively at the interconnect company I worked for. I now have several WE KSU's hooked into a Mitel PBX, using an assortment of cards. BTW there is a simple mod that can be used on pre-ISS 15 400D;s to allow bridged ringing, its is available on the TCI website www.telephonecollectors.info/

And all the stuff made it's way to scrap yard.. I should have known...

What the hell are these cards? Some kind of communications circuitry. I'm a 90's kid do they still use this stuff? Just get a cell phone.