Skip to main content
Tube Tinker — Electron Tube Database
Alternatives & variationsDownload PDF datasheet

Power - Triode (over 1000V 100W) ·Triode

TB25300

Directly heated Philips RF and AF transmitting triode for power-amplifier service. Rated for approximately 135 W plate dissipation and 2.5 kV plate voltage, with moderate gain and manufacturer operating data for transmitting applications.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
B5F
Base pins
-
Nominal heater
6.3 V / 5.4 A

Description

TB25300 is a Philips RF/AF transmitting triode. The supplied datasheet provides direct-filament data, RF/AF ratings, capacitances and high-power operating conditions.

Socket description

Giant 5-contact all-glass base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
B5F
Base pins
-
Nominal heater voltage
6.3 V
Nominal heater current
5.4 A
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

Terminal pinout

Electrical assignments shared by every tube using this base designation.

No verified pinout is recorded for this base designation.

Section ratings

1 physical section, each with unique specifications.

Section 1

Triode

X-ray radiationInterelectrode capacitances
Transconductance
0.0028 S
Amplification factor
25
Max plate voltage
2500 V
Max plate dissipation
135 W
Max cathode current
250 mA

Published filament, capacitance, typical characteristics, limiting values and RF/AF operating tables reviewed.

Source-dependent data

Operating conditions by source

Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.

Data set 01

1963 Philips Electron Tubes Handbook V4

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristic

  • Filament voltage

    6.3 V

    DirectlyHeated

  • Filament current

    5.4 A

    DirectlyHeated

  • Amplification factor

    25

    Published

  • Transconductance

    2800 µS

    Published

Other

  • Maximum plate voltage

    2500 V

    Published limit

  • Maximum plate dissipation

    135 W

    Published limit

  • Maximum cathode/plate current

    250 mA

    Published limit

Capacitance

  • Plate capacitance

    0.1 pF

    Published

  • Grid capacitance

    4.3 pF

    Published

  • Grid-to-plate capacitance

    5.2 pF

    Published

Data set 02

1999 Philips E-Z

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristics

  • Filament voltage Ve

    6.3 a

    Filament voltage Ve = 6.3V

  • Filament current If

    5.4 a

    Filament current If = 5.4 A

  • Anode to all other elements except grid Caq

    100 mA

    Anode to all other elements except grid Caq = 0.1 pF

  • Grid to all other elements except anode Cg

    4.3 a

    Grid to all other elements except anode Cg = 4.3 pF

  • Anode to grid Cag

    5.2 A

    Anode to grid Cag = 5.2 pF

  • Anode connector 40624

    40624 A

    Anode connector 40624

  • Socket with grounded grid connections 40215/01

    1 S

    Socket with grounded grid connections 40215/01

  • * Anode red hot, temperature

    850 A

    * Anode red hot, temperature = 850 ©C.

  • RF power triode TB2.5/7300

    7300 w

    RF power triode TB2.5/7300

  • Wavelength

    4 W

    Wavelength = 4 4 4 4 m

  • Anode voltage 15 00 1000 V

    1000 A

    Anode voltage 15 00 1000 V

  • Grid voltage -1 10 -80 V

    -80 v

    Grid voltage -1 10 -80 V

  • Anode current 2 05 205 mA

    205 A

    Anode current 2 05 205 mA

  • Grid current 40 40 mA

    40 mA

    Grid current 40 40 mA

  • Grid input power 11 10 W

    10 w

    Grid input power 11 10 W

  • Anode input power

    205 A

    Anode input power = 512 410 3 08 205 W

  • Anode dissipation

    79 A

    Anode dissipation = 122 115 98 79 W

  • Wavelength 4 4 n

    4 W

    Wavelength 4 4 n

  • Anode voltage 2500 2000 1500 V

    1500 A

    Anode voltage 2500 2000 1500 V

  • Grid voltage -87 -45 Vv

    -45 v

    Grid voltage -87 -45 Vv

  • Anode current 77 120 mA

    120 A

    Anode current 77 120 mA

  • Anode input power 193 180 W

    180 A

    Anode input power 193 180 W

  • Anode dissipation 128 121 W

    121 A

    Anode dissipation 128 121 W

  • Grid current 52 mA

    52 mA

    Grid current 52 mA

  • Grid input power 9.4 W

    9.4 w

    Grid input power 9.4 W

  • Wavelength A

    4 W

    Wavelength A = 4 4 4 m

  • Anode voltage Va

    1000 A

    Anode voltage Va = 2000 1500 1000 V

  • Grid voltage Vg

    -130 v

    Grid voltage Vg = =225 ~-180 -130 V

  • Anode current I,

    255 A

    Anode current I, = 255 255 255 mA

  • Grid current Ig

    80 mA

    Grid current Ig = 80 80 80 mA

  • Grid input power Wig

    23 w

    Grid input power Wig = 30 27 23 W

  • Anode input power Wia

    255 A

    Anode input power Wia = 510 382 255 W

  • Anode dissipation W,

    65 A

    Anode dissipation W, = 102 76 65 W

  • Modulation power Wmod

    126 a

    Modulation power Wmod = 255 191 126 W

  • Wavelength A

    1.5 W

    Wavelength A = 2 2 1.5 m

  • Anode voltage Va

    2000 A

    Anode voltage Va = 2500 2000 2000

  • Anode current I

    346 A

    Anode current I = 410 410 346 mA

  • Grid resistor Rg

    1875 s

    Grid resistor Rg = 2500 1875 1875 Q@

  • Anode input power Wia

    692 A

    Anode input power Wia = 1025 820 692 W

  • Anode dissipation W,

    270 A

    Anode dissipation W, = 245 230 270 W

  • Grid input power Wig

    26 w

    Grid input power Wig = 28 26 26 W

  • RF power triodes TB2.5/300

    300 w

    RF power triodes TB2.5/300

  • Wavelength A

    7.3 W

    Wavelength A = 7.3 m

  • Anode voltage vV,

    2000 A

    Anode voltage vV, = 2000 Vv b

  • Anode current I,

    170 A

    Anode current I, = 170 mA

  • Grid current Ig

    34 mA

    Grid current Ig = 34 mA

  • Grid resistor Rg

    3750 s

    Grid resistor Rg = 3750 @

  • Anode input power Wi,

    420 A

    Anode input power Wi, = 420 W

  • Anode dissipation W,

    120 A

    Anode dissipation W, = 120 W

Other

  • Amplification factor

    25 A

    Amplification factor = 25

  • Anode voltage Va max. 2500 V

    2500 A

    Anode voltage Va max. 2500 V

  • Anode dissipation™ W, max. 135 W

    135 A

    Anode dissipation™ W, max. 135 W

  • Grid dissipation Wg max. 16 W

    16 s

    Grid dissipation Wg max. 16 W

  • Grid circuit resistance with fixed grid bias Rg max. 0,1 MQ

    0.1 s

    Grid circuit resistance with fixed grid bias Rg max. 0,1 MQ

  • Grid circuit resistance with automatic grid bias Rg max. 0,2 MQ2

    0.2 s

    Grid circuit resistance with automatic grid bias Rg max. 0,2 MQ2

  • Cathode current 1k max. 250 mA

    250 a

    Cathode current 1k max. 250 mA

  • Peak cathode current Ikp max. 1,6 A

    1.6 a

    Peak cathode current Ikp max. 1,6 A

  • Temperature of anode seal max. 220 oC

    220 a

    Temperature of anode seal max. 220 oC

  • Bottom temperature max. 180 oC

    180 a

    Bottom temperature max. 180 oC

  • Peak grid AC voltage 3 00 260 V

    260 a

    Peak grid AC voltage 3 00 260 V

  • Output power

    126 w

    Output power = 390 295 2 10 126 W

  • Efficiency

    5 %

    Efficiency = 76 72 68 6L.5 %

  • Peak grid AC voltage 100 100V

    100 a

    Peak grid AC voltage 100 100V

  • Output power 59 W

    59 w

    Output power 59 W

  • Efficiency 33 %

    33 %

    Efficiency 33 %

  • Peak grid AC voltage Vgp

    320 a

    Peak grid AC voltage Vgp = 415 370 320V

  • Output power W,

    190 w

    Output power W, = 408 306 190

  • Efficiency n

    7.5 %

    Efficiency n = 80 80 7.5 %

  • Output power W,

    396 w

    Output power W, = 752 564 396 W

  • Efficiency n

    57 %

    Efficiency n = 73 69 57 %