This circuit from a Popular Electronics from the 90's can generate signals from 0.03 Hz to 3 kHz depending on the value of the capacitor and resistor.
This circuit consists of a simple continuity test with two transistors forming a relaxation...
This circuit is a manual of 1972 RCA power transistors. The critical components of the project are...
Found in the 1974 Ferranti transistor manual, this Schmitt trigger circuit uses general-purpose transistors...