Variable Frequency Oscillator

Variable-frequency oscillator (VFO) ( English : oscillator with variable frequency ) is the generic term for all tunable oscillator circuits or frequency generators . As a rule, either the capacitor or the inductance of a resonant circuit is changed. VFO generators are mainly used in radio technology.

VFOs are usually as a voltage controlled oscillator (ger .: Voltage Controlled Oscillator (VCO)) or as a digitally controlled oscillator (ger .: Digitally Controlled Oscillator realized (DCO)).