6AF3 is a miniature glass triode vacuum tube that was commonly used in consumer radios and televisions for intermediate frequency (IF) amplification and other applications. It was manufactured by RCA and other makers during the 1940s and 1950s. The tube was notable for its small size, being only 0.78 inches (19.6 mm) in length and 0.435 inches (11 mm) in diameter. The base was a 4-pin Noval type. The tube was designed to operate as an amplifier at frequencies up to 350 kHz, and it could amplify signals up to 30 mV. In addition, it had a good sensitivity and was capable of providing a good frequency response.