Classification- Dome-type bulb of glass, a white ceramic base with four-prong bayonet golden pins, oxide coated filamentary, mesh plate or carbon plate triode.

Application -Audio frequency amplifier where power outputs of approximately 10 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.

PX25_01_en

Nominal operating conditions and parameters
Filament voltage* ………………………………………………………… 4.0V or 5.0V
Nominal filament current ………………………………………………… 2A or 1.6A
Plate voltage ………………………………………………………………… 400V
Grid voltage** ……………………………………………………………… -30V
Plate current ………………………………………………………………… 62.5mA
Impedance ……………………………………………………………………1265 ohms
Amplification factor …………………………………………………………… 9.5
Mutual Conductance ………………………………………………………… 7.5 mA/V
Grid current …………………………………………………………………… 0.05 μA

*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.
Measured at Va=100; Vg=0

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.

PX25_02

 

Fig. 3

Limiting Operation Conditions for Safe Nor simultaneous ratings
Maximum plate voltage ………………………………………………… 500 volts
Maximum plate dissipation …………………………………………… 30 watts