We found this tube receiver in a 1950s Japanese publication. The circuit uses 5 tubes and has an RF amplifier stage for greater sensitivity. The power supply is not shown on the circuit.
Found in documentation from the 1970s, this circuit for resistive loads uses a trigger...
This simple receiver for listening on the phone was obtained in a 1960 documentation. The circuit is...
This circuit was found in the 1989 Radio Electronics Experimenter edition. The circuit has the...