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 6-transistor commercial radio with 6 V supply was found in a Japanese publication from the...
This latching alarm circuit using relays was found in American documentation. Sensors are...
We found this circuit in the 1989 Radio Electronics Experimenter. The circuit uses common...