This two-microphone amplifier was found in a April 1961 Radio Electronics Magazine. The circuit is powered by battery and has a 600-ohm line output.
This circuit is one of many that the reader can find in this section for testing crystals. The...
This circuit that uses only transistors indicates when the voltage in the circuit has the voltage...
This circuit was found in a 1981 publication and consists of an interesting handicraft game. The...