Found in an English documentation, this circuit serves as a receiver for modulated sources of ultrasound. The sensor is a ceramic capsule. Transistors are general purpose types.
This micro AM radio will tune strong stations in the frequency range between 530 and 1,600 kHz....
This circuit was obtained in a Electronics World of 1968. The transistors can be equivalent as the BC558...
Based on an integrated circuit of the time, this circuit appeared in the October 1979 issue of...