Crystal Radio (CB21773E)

This radio with selector switch tuning was found in a Popular Electronics from May 1956. Listening is through a crystal or high impedance earphone.

Component Tester (CB4313E)
This circuit consists of a simple continuity test with two transistors forming a relaxation...
100 W Inverter (2) (CB13974E)
This circuit is a manual of 1972 RCA power transistors. The critical components of the project are...
High speed trigger (CB21850E)
Found in the 1974 Ferranti transistor manual, this Schmitt trigger circuit uses general-purpose transistors...