Classification- Dome-type or Aubergine-type bulb of glass, a white ceramic base with four-prong bayonet golden pins, oxide coated filamentary, solid plate or mesh or carbon plate triode. Application -Audio frequency amplifier where power outputs of approximately 8.5watts 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* …………………………………………………………… 5V or 2.5V Nominal filament current …………………………………………………… 1.2A or 2.4A Plate voltage ………………………………………………………………… 300V Grid voltage** ……………………………………………………………… -58V Plate current ………………………………………………………………… 60mA Amplification factor …………………………………………………………… 3.85 Grid to plate transconductance …………………………………………… 5.7mA / V Grid current ………………………………………………………………… 0.05 μ A Plate resistance …………………………………………………………… 700 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 4. shown typical curves of plate currents of grid voltage for several values of plate voltages. It is alternating-current filament supply.
Fig. 4 Limiting Operation Conditions for Safe Nor simultaneous ratings Maximum plate voltage ………………………………………………… 450 volts Maximum plate dissipation …………………………………………… 40 watts Maximum plate current of average tube for fixed gird bias ………… 70mA Maximum plate current of manually adjusted gird or self-biasing circuit……………………………… 100mA
