Found in an American circuit manual from the 1970s, this circuit can use any general-purpose transistor. The operating frequency range is from 600 to 4000 Hz.
The frequency of this oscillator depends on T, which for the audio band can be a common output...
This circuit can work with almost any JFET. The circuit is from an Electronics Now from April...
This voltage-controlled oscillator uses components that are still common in our market. The...