The 9A8 is a multi-unit glass vacuum tube featuring a medium-mu triode and a sharp-cutoff pentode housed in a single 9-pin miniature envelope. Designed primarily for television receiver circuitry—commonly utilized in vertical deflection oscillator and amplifier stages or audio output applications—it features a 9.0-volt, 450mA heater designed for series-string tube filament configurations. Also applied in various radio reception circuits and vintage audio/receiver equipment that required high-frequency switching or amplification. Manufactured by companies such as RCA, Sylvania, GE, and Tung-Sol, this tube provides reliable dual-section performance for vintage television chassis restoration and specialized electronics repair. Also known by its European equivalent designation, the PCF80.