Classification-Dome-type or Aubergine-type bulb of glass, a white ceramic base with four-prong bayonet gold pins , oxide coated filamentary, mesh plate ,cabon plate triode.
Application-Audio frequency amplifier where power outputs of approximately 3.5 watts or less is required at relatively low plate voltages.
Dimensions-Dimensions, outline diagrams of the tube and bases, and the arrangement of electrode connections to the base terminals are shown in Figures 1, 2 and 3.

Nominal operating conditions and parameters

Filament voltage……………………………………………2.5 V*
Nominal filament current…………………………………2.5A
Plate voltage…………………………………………………250V
Grid voltage………………………………………………－45 V**
Plate current…………………………………………………60 mA
Plate current………………………………………………62.5 mA
Amplification factor……………………………………… 4.2
Grid to plate transconductance……………………5250 micromhos
Grid current……………………………………………… 0.05 μA
Plate resistance……………………………………………800 ohms
Load resistance……………………………………………2.5 kohms Maximum plate

*Alternating-current filament supply or Direct-current filament supply.
**Alternating-current filament supply is used. The grid and plate returns should be connected to a center tap on the secondary of the filament transformer.
***Direct-current filament supply is used. The grid and platter returns are connected to the negative end of the filament.

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.

Fig.3

Limiting Operation Conditions for Safe Nor-nor simultaneous ratings
voltage…………………………………………………………300 volts
Maximum plate dissipation…………………………… 15 watts