Classification- It is a Twin triode. Dome-type bulb of glass, copper ceramic base with eight golden pins.Application -It intended for use a voltage amplifier or Phase inuerter. Dimensions -Dimensions, outline diagrams of the tube and bases, and the arrangement of electrode connections to the base terminals are shown in the below drawings. 
Nominal operating conditions and parameters Heater voltage ……………………………………………………………… 6.3V Heater current ……………………………………………………………… 0.6A Plate voltage ………………………………………………………………… 250V Grid voltage ………………………………………………………………… -8V Plater resistance ………………………………………………………… 7.7kohms Plate current ………………………………………………………………… 9mA Amplification factor …………………………………………………………… 20 Heater-cathode voltage ……………………………………………………… 90V Characteristics-Average characteristics Figure 3. shown typical curves of plate currents of grid voltage for several values of plate voltages. It is alternating-current filament supply.
Limiting Operation Conditions for Safe Nor simultaneous ratings Maximum plate voltage ………………………………………………… 300 V Maximum Grid voltage ………………………………………………… -50V Maximum Grid voltage ………………………………………………… 0V Maximum Power of plate …………………………………………… …2.5W
