The 6AF9 is a type of pentode tube (valve) manufactured by RCA. It has a metal/ceramic base, and it is mainly used in audio amplification circuits. It has a heater voltage of 6.3V, and its plate voltage can range between 250 and 450V. It has a maximum plate dissipation of 7.5 watts, and its transconductance is 5.5 mA/V. Other features of the 6AF9 include a resonance frequency of 40.5 MHz, a typical noise figure of 16 dB, and a peak anode current of 0.3 mA.