We found this circuit in the Radio Electronics magazine of February 1993. The main integrated circuit is from that time and the power supply is made with voltages of 6 to 15 V.
This detector with ultra-low deviation was found in an American documentation from the 90s....
This circuit is from an old Popular Electronics, but it can be easily implemented nowadays, even...
This is the configuration of this type of oscillator given in an article in Electronics Now...