6DW4

Half-Wave Vacuum Rectifier Diode, engineered to handle high inverse voltage pulses up to 5,000V peak. Operating with a 6.3V heater, it functions as a high-efficiency damper diode in television horizontal deflection circuits to suppress inductive ringing and recover wasted energy, housed in a standard 9-pin miniature glass envelope (Noval, T-6.5 bulb).