What is frequency control? Why is frequency control important in electronic circuits? Frequency control components keep resonant circuits tuned to a particular frequency, preventing bandpass frequencies drifting especially in radio equipment. The most common type of frequency control components are ceramic resonators, quartz crystals and crystal oscillators. All in-stock resonators, crystals and oscillators are despatched the same day from Rapid. If you are looking for high quality frequency control components for your application requirements and we do not have what you need today, we may be able to source the components for you. Please contact us for details.