6BK7B

Medium-Mu Dual Triode Amplifier Tube, featuring an internal shielding barrier between the two triode sections to prevent cross-talk. Operating with a 6.3V heater, it is highly optimized for use as a low-noise VHF cascode RF amplifier or localized oscillator in television tuners, housed in a standard 9-pin miniature glass envelope (Noval, T-6.5 bulb).