Classification--It is a Twin triode. It is a nine pins tube.oxide coated cathode of indirect heated.
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 commections to the arrangement of electrode connections to the base terminals are shown in Figures 1 and 2 .

Nominal operating conditions and parameters

Heater voltage……………………………………………………………12.6 V
Heater current……………………………………………………..........0.15 A
Plate voltage………………………………………………………………250 V
Grid voltage……………………………………………………………….－8.5 V
Plate resistance…………………………………………………………7.7 kohms
Plate current………………………………………………………………10.5 mA
Amplification factor…………………………………………………………17

Characteristics-Average characteristics

Figure 3. shown typical curves of plate currents as a function of grid voltage for several values of plate voltages.

Fig.3

Limiting Operation Conditions for Safe Nor-nor simultaneous ratings

Maximum plate voltage……………………………………………… 300 V
Maximum Grid voltage………………………………………………-- 50 V
Maximum Grid voltage………………………………………………....0 V
Maximum Power of plate……………………………………………2.75 W