Classification-Dome-type bulb of glass, a white ceramic base with four-prong bayonet gold pins , oxide coated filamentary, mesh plate triode.
Application-Audi amplifier Class A Service, Radio Amplifier Class B Service. Oscillaator Class C Service.
Dimensions-Dimensions, outline diagrams of the tube and bases, and the arrangement of electrode connections to the base terminals are shown in Figures 1 and 2.

Nominal operating conditions and parameters

Filament voltage………………………………………………………………5.0 V*
Nominal filament current…………………………………………………… 1.2 A
Plate voltage…………………………………………………………………400 V
Grid voltage…………………………………………………………………－24 V
Plate resistance--------------------------------------------------------------------2.5 kohms
Plate current………………………………………………………………50mA
Amplification factor………………………………………………………… 7.3

*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 plate 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

Maximum plate voltage…………………………………………………………450 volts
Maximum plate diissipation……………………………………………………30 watts
Maximum plate current…………………………………………………………80mA