A voltage-controlled oscillator is a free-running oscillator with a stable frequency of oscillation that depends on a timing capacitance, a timing resistance and an external control voltage. In this experiment, the operation of a nXR-2207 monolithic linear integrated circuit voltage-controlled oscillator is examined. In the voltage-controlled oscillator GUI, users can change the voltage status of two inputs while affecting the output frequency. The voltage status is changed by a timing resistor and capacitors to vary the output frequency. The oscillator produces two wave shapes, square and sine.