How does a No. 1 Crossbar work? - Dial Equipment Appreciation, Part 2
13:40
How does MF signaling work? - Dial Equipment Appreciation, Part 3
23:20
How does a No. 1 Crossbar Marker work?
10:21
The Beautiful Life Of A Telephone Operator. Wouldn't This Convince You To Become One?
16:31
How does call tracing work? (Part 1)
23:44
Electromechanical switching methods for telephone exchanges Part 2
41:36
Why isn't the 1XB completing calls?
24:51
Bits, Bytes, and Bauds, Telecommunications for TOPS.
8:54