The Basic Digital Telephone experiment card set is designed for use with the Model 130ST trainer. Students are introduced to the elements of a communications system, including circuits, components, bandwidth, and noise as limiting factors. Hands-on work covers telephone-set operation and measurement of signals in the local loop of an electronic telephone set.

The Advanced Digital Telephone experiment card set covers two signal-processing methods at block-diagram level—analog time division multiplexing and digital pulse code modulation—and fiber optics as a transmission medium, also at block-diagram level.