This circuit generates short pulses. The transistor can be a 2N2222 or BC548 and the frequency is given by the resistors and the capacitor that can be changed.
This adjustable frequency circuit was found in December 1986, Radio Electronics magazine. The base...
The source of the figure was found in a 1981 magazine and is recommended for the experimenter's bench. The...
Capacitors C2, C3 and C4 determine the frequency of this simple oscillator. Transistor can be...