This oscillator for the fifth overtone of a crystal was found in a Radio Electronics magazine from May 1970. Transistors are RF types, and the transistor determines the maximum frequency achieved.
This two-color LED indicator was found in a Popular Electronics from the 90's. The transistor...
This circuit was found in a Radio Electronics from the 90's. It provides lower frequency signals from...
This monostable circuit uses one of the two flip-flops available on the CMOS 4098 integrated...