The original purpose of this circuit, which we find in old American documentation, is to modulate an RF carrier for telecommunications applications. Transistors support equivalents.
In this circuit the capacitor under test is charged at switch position A and then discharged...
This is a common circuit in the 1990s, when experimental FM transmitters were in vogue. The...
Using a piezoelectric sensor of the time, this circuit was found in the February 1994 issue of...