This circuit is from a 1980's documentation for telecommunications. The circuit is used in SSB and the diodes must be suitable types for the application. The audio input is low impedance.
This circuit was found in an American audio documentation from 1968. The configuration can be...
This is a small audio amplifier for headphones for experimental receivers. The transistor can be...
This circuit was found in the July 1992 Radio Electronics magazine. Sensitivity adjustment is made...