Originally posted by EV607797:
I've never seen that KTU before.
Me either, Ed. I'm with you - It's got to be a device for "neatly" terminating components you needed to add to a larger (1A1 or 6A system).
My guess is that you would remove the front screw panel, wire up whatever components (diodes, capacitors, etc.) you needed for a circuit to the wire wrap terminals on the back, tuck them all in neatly, replace the front panel and then make your wiring connections to the system on the front screw terminals.
The components are now hidden away behind the plate, making for a nice, clean "Bell System approved" install.
Sam
