The circuit shown in the figure is characterized by stability and the use of a common component. This circuit can generate signals in the range from 100 kHz to 500 kHz depending only on the crystal used. The component values are for a 12 V supply with the indicated transistor, originally manufactured by RCA. Double-gate equivalents can be experimented with possible changes in the polarization components. Changes in the 100 ohms resistor, in series with the power supply, allow the use of sources with other voltages. Remember that the current drained by the step is of the order of 8 mA. This allows you to calculate the voltage drop across the resistor.
