This circuit is from a Radio Electronics magazine from May 1986. Observe the voltages applied to the capacitors, taking care that the capacitor under test can withstand them.
This circuit must have its input connected to the collector of the last IF transistor of the FM...
We found this circuit in a Texas Instruments Opto Electronics manual from 1992. In it we have the...
In reality, it is an audio oscillator that is triggered by a structure that forms a bell-shaped sensor....