This circuit was obtained from an Electronic Design from 1964. Transistors admit modern equivalents and the range of frequencies generated can be changed.
In fact, the original American publication exaggerated a little about the range that a good...
We found this circuit in an American documentation from the 90s. Through an LED it indicates the...
August 2017 - Mouser Electronics is announcing the availability of TDK ICS-52000 microphones with...