TOSHIBA 8T25RA

8T25RA is a forced air cooled, ceramic—metal medium-mu power triode containing a thoriated tungsten carbide cathode, of which the plate input power up 31kW when operating at Class C. The tube  used primally in hign frequency heating service.
GENERAL  CHARACTERISTICS
Filament Voltage ………………………  8±  0.5 V
Filament Current  ……………………………110  A
Maximum Filament Impact Current …………  20  A
Amplification Factor……………………………20
Transconductance (Ia=2A) ………………… 24 mA/V
Interelectrode Capacitance
Grid Plate  ………………………………   32 pF
Grid Cathode ……………………………   46 pF
Plate Cathode ……………………………  1.8 pF
Maximum Operation Frequency  ……………40  MHz
Maximum Height  …………………………    386 mm
Maximum Diameter  ………………………    204 mm
Appro.Weight …………………………………18  kg
Operation Position  ………………Vertical, base down
Cooling   …………………………………   Forced Air
Minimum Air Flow  ………………………  25 m3/min
Minimum Static Pressure Intencity  …………   980 Pa
Maximum É¢ÈÈÆ÷ Operation Temprature  …… 250 ¡æ
Maximum In-coming Air Temprature…………   40 ¡æ
Maximum Seal and Anode CoreTemprature…   250 ¡æ
MAXIMUM RATING ABSOLUTE £¦#118alue
RF Power Amplifier and Oscillator - Class C Telegraphy
DC Plate Voltage ……………………………14 kV
DC Grid Voltage …………………………… -2  kV
DC Plate Current  …………………………  4.5  A
DC Grid Current  …………………………   0.8  A
Plate Dissipation  …………………………    15  kW
Grid Dissipation  …………………………   400  W

TYPICAL OPERATION (Oscillator)
DC Plate Voltage ……………………10        12 kV
DC Plate Current ……………………  4       3.7  A
DC Grid Current ……………………0.4       0.4  A
Grid Impedance……………………2500    2800 Ω
Plate Input Power  ……………………28       31  kW