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Power - Pentode Single (NOT beam) (under 10W) ·Pentode

3V4

Directly heated miniature power-output pentode for battery-operated audio amplifiers. Its low filament demand and compact construction provide useful low-frequency output power in portable equipment.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: 6BX
Socket code: B7G
Base pins: 7
Nominal heater: 2.8 V / 50 mA

Description

Directly heated miniature power-output pentode for battery-operated audio amplifiers.

Socket description

Miniature 7-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: 6BX
Socket code: B7G
Base pins: 7
Nominal heater voltage: 2.8 V
Nominal heater current: 50 mA
Parallel heater voltage: 1.4 V
Parallel heater current: 100 mA
Series capable: Yes

6BX - Terminal pinout

Electrical assignments shared by every tube using this base designation.

Terminal	Section	Connection	Evidence
PIN1F	—	F — Filament Source code F; independent manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 6BX
PIN2P	A	P — Plate (Anode) Source code P; independent manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 6BX
PIN3G2	A	G2 — Screen Grid Source code G2; independent manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 6BX
PIN4IC	—	IC Source code IC; independent manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 6BX
PIN5G3	A	G3 — Suppressor GridGroup 6BX5 Source code G3; independent manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 6BX
PIN5FCT	—	FCT — Filament Center TapGroup 6BX5 Source code FCT; independent manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 6BX
PIN6G1	A	G1 — Control Grid Source code G1; independent manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 6BX
PIN7F	—	F — Filament Source code F; independent manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 6BX

Section ratings

1 physical section, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 100000 Ω
Transconductance: 0.00215 S
Max plate voltage: 90 V
Max screen voltage: 90 V
Max plate dissipation: 1 W
Max cathode current: 12 mA

Promoted design-center maximum ratings and a representative 90 V Class A characteristic point; alternate published operating points preserved as parameters.

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

1958 Brimar Radio Valve No 7

Published operating points and test conditions from this source.

SECTION 1

Pentode

Application

Application
Battery audio output

Data set 02

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Plate voltage
90 V
ClassA;ParallelFilaments
Screen-grid voltage
90 V
ClassA;ParallelFilaments
Grid No.1 bias
4.5 V
ClassA;ParallelFilaments
Plate current
9.5 mA
ClassA;ParallelFilaments
Screen-grid current
2.1 mA
ClassA;ParallelFilaments
Plate resistance
100000 ohm
ClassA;ParallelFilaments
Transconductance
2150 uS
ClassA;ParallelFilaments
Load resistance
10000 ohm
ClassA;ParallelFilaments
Power output
0.27 W
ClassA;ParallelFilaments
Plate voltage
85 V
ClassA;ParallelFilamentsLowVoltage
Screen-grid voltage
85 V
ClassA;ParallelFilamentsLowVoltage
Grid No.1 bias
5 V
ClassA;ParallelFilamentsLowVoltage
Plate current
6.9 mA
ClassA;ParallelFilamentsLowVoltage
Screen-grid current
1.5 mA
ClassA;ParallelFilamentsLowVoltage
Plate resistance
120000 ohm
ClassA;ParallelFilamentsLowVoltage
Transconductance
1975 uS
ClassA;ParallelFilamentsLowVoltage
Load resistance
10000 ohm
ClassA;ParallelFilamentsLowVoltage
Power output
0.25 W
ClassA;ParallelFilamentsLowVoltage
Plate voltage
90 V
ClassA;SeriesFilaments
Screen-grid voltage
90 V
ClassA;SeriesFilaments
Grid No.1 bias
4.5 V
ClassA;SeriesFilaments
Plate current
7.7 mA
ClassA;SeriesFilaments
Screen-grid current
1.7 mA
ClassA;SeriesFilaments
Plate resistance
120000 ohm
ClassA;SeriesFilaments
Transconductance
2000 uS
ClassA;SeriesFilaments
Load resistance
10000 ohm
ClassA;SeriesFilaments
Power output
0.24 W
ClassA;SeriesFilaments

Data set 03

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

Transconductance
2150 uS
Typical

Other

Power Output
0.27 W
Typical

Data set 04

1966 Tung Sol Electronic Tubes 1 of 4

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Filament voltage series
2.8 V
Series
Filament current series
50 mA
Series
Filament voltage parallel
1.4 V
Parallel
Filament current parallel
100 mA
Parallel
Plate voltage
90 V
AudioOutput;ClassA
Screen voltage
90 V
AudioOutput;ClassA
Control-grid voltage
-7 V
AudioOutput;ClassA
Plate current
9.5 mA
AudioOutput;ClassA
Screen current
2 mA
AudioOutput;ClassA
Load resistance
8000 Ω
AudioOutput;ClassA
Power output
0.25 W
AudioOutput;ClassA

Data set 05

1968 General Electric Co

Published operating points and test conditions from this source.

SECTION 1

Pentode

Capacitance

Grid 1 to plate capacitance
0.2 pF
Input capacitance
5.5 pF
Output capacitance
3.8 pF

Characteristic

Plate resistance
100000 ohm
ClassA;ParallelFilament;Plate90V;Screen90V
Transconductance
2150 uS
ClassA;ParallelFilament;Plate90V;Screen90V
Zero-signal plate current
9.5 mA
ClassA;ParallelFilament;Plate90V;Screen90V
Zero-signal screen current
2.1 mA
ClassA;ParallelFilament;Plate90V;Screen90V

Other

Load resistance
10000 ohm
ClassA
Maximum-signal power output
0.27 W
ClassA;ParallelFilament;Plate90V;Screen90V