This 1967 General Electric circuit makes use of an array of 3 (integrated) transistors for an amplifier stage. The circuit has a 500 mV output.
This circuit was obtained in a 90s documentation. However, it can be developed with modern...
This circuit uses a 455 kHz crystal or for close frequencies. We found it in documentation from...
This circuit turns off after a time that depends on C1. The circuit is from an Electronics Now...