Classification-Dome-type bulb of glass, a white ceramic base with four-prong bayonet gold pins , oxide coated filamentary, mesh plate, canbon plate triode.
Application-Audio frequency amplifier where power outputs of approximately 25 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 and 2.

Nominal operating conditions and parameters

Filament voltage………………………………………………………………7.5 V*
Nominal filament current……………………………………………………1.35 A
Plate voltage………………………………………………………………… 450 V
Grid voltage…………………………………………………………………－84 V**
Grid voltage…………………………………………………………………－82 V***
Plate current………………………………………………………………… 55 mA
Plate current…………………………………………………………………-57 mA
Amplification factor………………………………………………………… 3.8
Grid current………………………………………………………………… 0.05 μA
Plate resistance………………………………………………………………1800 ohms

*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.

Limiting Operation Conditions for Safe Nor-nor simultaneous ratings
Maximum plate voltage………………………………………………………… 450 volts
Maximum plate dissipation……………………………………………………… 25 watts

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