<< PX25/n PX25/n/5v Vacuum Tube



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.

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 ¦ÌA

*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.

Fig 3

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