<< Product 205D 205D/n Vacuum Tube




Classification-Globe-type bulb of glass, a white ceramic base with four-prong bayonet gold pins , oxide coated filamentary, solid plate, 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”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­4.5 V*
Nominal filament current”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­ 1.2 A
Plate voltage”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­300 V
Grid voltage”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­£­24 V
Plate resistance--------------------------------------------------------------------5.0 kohms
Plate current”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­15 mA
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”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­ 400 volts
Maximum plate diissipation”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­14 watts
Maximum plate current”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­”­50mA