Dynamic compressor (CB21762E)

This circuit was found in a 1977 publication for radio amateurs. Transistors are common general-purpose types of the time.

Simple field strength meter (CB4114E)
The more sensitive the instrument used the better the sensitivity of the indicated meter. We...
Telephone dialing simulator (CB8658E)
Based on the 4017 integrated circuit, this circuit of a European 303 Circuits from the 90s,...
White Noise Generator (CB19614E)
The integrated circuit used in this project is unusual and it includes internal transistors that...