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

Power - Beam (NOT sweep) ·BeamPower

7408

Beam-power tube designed as an output amplifier in high-quality sound systems, providing substantial audio-frequency power capability.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
IO
Base pins
8
Nominal heater
6.3 V / 450 mA

Description

Beam power tube used as an output amplifier in high-quality sound systems.

Socket description

International Octal

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
IO
Base pins
8
Nominal heater voltage
6.3 V
Nominal heater current
450 mA
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

Beam Power

X-ray radiationInterelectrode capacitances
Plate resistance
50000 Ω
Transconductance
0.0040999999999999995 S
Max plate voltage
350 V
Max screen voltage
315 V
Max plate dissipation
14 W
Max screen dissipation
2.2 W
Max cathode current
100 mA

Promoted only from clearly labeled printed ratings/characteristics; specialized and operating data retained in parameter rows.

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

1965 Sylvania Electronic Tubes Vol3

Published operating points and test conditions from this source.

SECTION 1

Beam Power

Characteristic

  • Heater Voltage

    6.3 V

  • Heater Current

    450 mA

  • Grid To Plate Capacitance

    0.7 pF

  • Input Capacitance

    9 pF

  • Output Capacitance

    5.5 pF

  • Transconductance

    4100 uS

Other

  • Plate Voltage

    250 V

    ClassA

  • Screen Voltage

    250 V

    ClassA

  • Grid Voltage

    -12.5 V

    ClassA

  • Plate Current

    45 mA

    ClassA

  • Screen Current

    4.5 mA

    ClassA

  • Load Resistance

    5000 ohm

    ClassA

  • Power Output

    4.5 W

    ClassA

  • Power Output

    14 W

    TwoTubes;PushPull;ClassAB

Data set 02

1968 General Electric Co

Published operating points and test conditions from this source.

SECTION 1

Beam Power

Other

  • Plate Voltage . . . . . .. ..o 350 Volts Pin 3—Plate

    350 Volts

    Published datasheet; semantic line recovery

  • Screen Voltage. . . ... ... e e 315 Volts Pin 4—Grid Number 2

    315 Volts

    Published datasheet; semantic line recovery

  • Plate Dissipation. . . . ... ... ... . . . 14 Watts (Screen)

    14 Watts

    Published datasheet; semantic line recovery

  • Screen Dissipation. . .. ... . .. ... ... 2.2 Watts

    2.2 Watts

    Published datasheet; semantic line recovery

  • DC Component. ... ... ... i, 100 Volts Pin 8—Cathode and Beam

    100 Volts

    Published datasheet; semantic line recovery

  • Total DCand Peak. . ....... ... ... ... ..o ouin.. 200 Volts Plates

    200 Volts

    Published datasheet; semantic line recovery

  • With Cathode Bias. . .. ... ... . ... .. ... . oo, 0.5 Megohms

    0.5 Megohms

    Published datasheet; semantic line recovery

  • Plate Voltage . . . ... . 60 250 Volts

    250 Volts

    Published datasheet; semantic line recovery

  • Screen Voltage. . .. ... .. . 250 250 Volts

    250 Volts

    Published datasheet; semantic line recovery

  • Grid-Number 1 Voltage . . . . ... ... .. . . 0 —12.5 Volts

    1 Volt

    Published datasheet; semantic line recovery

  • Grid-Number 1 Voltage . . . . ... ... .. . . 0 —12.5 Volts

    12.5 Volts

    Published datasheet; semantic line recovery

  • Peak AF Grid-Number 1 Voltage . . ........ ... .. . .. . .. . . . . . . ... — 125 Volts

    1 Volt

    Published datasheet; semantic line recovery

  • Peak AF Grid-Number 1 Voltage . . ........ ... .. . .. . .. . . . . . . ... — 125 Volts

    125 Volts

    Published datasheet; semantic line recovery

  • Plate Resistance, approximate. . . .. ... . . .. .. ... —_ 50,000 Ohms

    50000 Ohms

    Published datasheet; semantic line recovery

  • Transconductance . . . . ... ... ... —_ 4100 Micromhos

    4100 Micromhos

    Published datasheet; semantic line recovery

  • Zero-Signal Plate Current. . . .. ... .. ... . .. . 100 45 Milliamperes

    45 Milliamperes

    Published datasheet; semantic line recovery

  • Maximum-Signal Plate Current. . . . .. ... ... ... ... — 47 Milliamperes

    47 Milliamperes

    Published datasheet; semantic line recovery

  • Zero-Signal Screen Current. . . ......... ... ... 22 4,5 Milliamperes

    5 Milliamperes

    Published datasheet; semantic line recovery

  • Maximum-Signal Screen Current. . . .. ... .. ... . ... — 7.0 Milliamperes

    7 Milliamperes

    Published datasheet; semantic line recovery

  • Maximum-Signal Power Output. . ... ... .. .. .. .. . . . . — 4.5 Watts

    4.5 Watts

    Published datasheet; semantic line recovery

  • T Heater current of a bogey tube at Ef =6.3 volts.

    6.3 volts

    Published datasheet; semantic line recovery

  • Ke55611-T01 105 GRID-NUMBER 1 VOLTAGE IN VOLTS APRIL 15, 1960

    1 VOLT

    Published datasheet; semantic line recovery

  • Heater Voltage

    6.3 V

    Published datasheet

  • Heater Current

    450 mA

    Published datasheet

Data set 03

1971 RCA HB3 Binder 5 of 7

Published operating points and test conditions from this source.

SECTION 1

Beam Power

Other

  • Heater voltage

    6.3 V

  • Heater current

    450 mA

  • Plate voltage

    250 V

    ClassA

  • Screen voltage

    250 V

    ClassA

  • Plate current

    45 mA

    ClassA

  • Power output

    4.5 W

    ClassA

  • Maximum plate voltage

    350 V

  • Maximum screen voltage

    315 V

  • Maximum plate dissipation

    14 W

  • Maximum screen input

    2.2 W

  • Peak heater-cathode voltage heater negative

    200 V

  • Peak heater-cathode voltage heater positive

    200 V

Characteristic

  • Plate resistance

    50000 ohm

    ClassA

  • Transconductance

    4100 uS

    ClassA

Capacitance

  • Grid-to-plate capacitance

    0.7 pF

  • Input capacitance

    9 pF

  • Output capacitance

    7.5 pF

Data set 04

1975 RCA RC30

Published operating points and test conditions from this source.

SECTION 1

Beam Power

Other

  • Peak Heater-Cathode Voltage

    200 V

    AbsoluteValue

  • Average Heater-Cathode Voltage

    100 V

    AbsoluteValue

  • Typical Plate Voltage

    250 V

    ClassA

  • Typical Screen Voltage

    250 V

    ClassA

  • Grid No.1 Voltage

    -12.5 V

    ClassA

  • Zero-Signal Plate Current

    45 mA

    ClassA

  • Maximum-Signal Plate Current

    47 mA

    ClassA

  • Zero-Signal Screen Current

    4.5 mA

    ClassA

  • Maximum-Signal Screen Current

    7 mA

    ClassA

  • Load Resistance

    5000 ohm

    ClassA

Capacitance

  • Grid No.1 to Plate Capacitance

    0.7 pF

    ClassA