Screen-grid valves exhibited greater voltage gain and higher frequency capability than triodes, and permitted the development of the first true RF amplifiers in the MF and HF frequency ranges in radio equipment. They were commonly used as the first stage of radio-frequency amplification in domestic radio receivers in the period 1927 to 1930, after which they were superseded in this application by RF pentodes. Triodes were ill-suited to this type of application on account of their relatively high anode-grid capacitance and low anode resistance.