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

Voltage Pentode - Sharp Cutoff (single) ·Pentode

3AU6

Sharp-cutoff miniature pentode for wideband RF amplification and FM limiter service in high-frequency equipment.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
7BK
Socket code
B7G
Base pins
7
Nominal heater
3.15 V / 600 mA

Description

Sharp-cutoff miniature pentode for RF amplification in high-frequency wide-band equipment and for FM limiter service.

Socket description

Miniature 7-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
7BK
Socket code
B7G
Base pins
7
Nominal heater voltage
3.15 V
Nominal heater current
600 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

7BK - Terminal pinout

Electrical assignments shared by every tube using this base designation.

TerminalSectionConnectionEvidence
PIN1G1AG1 — Control Grid

EIA chart transcription; independent manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 128, 7BK

PIN2G3AG3 — Suppressor GridGroup 7BK2

EIA chart transcription; independent manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 128, 7BK

PIN2ISAIS — Internal ScreenGroup 7BK2

EIA chart transcription; independent manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 128, 7BK

PIN3H—H — Heater

EIA chart transcription; independent manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 128, 7BK

PIN4H—H — Heater

EIA chart transcription; independent manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 128, 7BK

PIN5PAP — Plate (Anode)

EIA chart transcription; independent manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 128, 7BK

PIN6G2AG2 — Screen Grid

EIA chart transcription; independent manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 128, 7BK

PIN7KAK — Cathode

EIA chart transcription; independent manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 128, 7BK

Section ratings

1 physical section, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances
Plate resistance
1000000 Ω
Transconductance
0.0052 S
Amplification factor
36
Max plate voltage
320 V
Max screen voltage
330 V
Max plate dissipation
3.5 W
Max screen dissipation
0.75 W
Max cathode current
18 mA
Rectifier warm-up time
11 s

Published ratings/characteristics promoted where semantically applicable; supplemental values retained in parameter table.

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

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Maximum plate voltage

    300 V

    Published handbook rating

  • Maximum screen voltage

    150 V

    Published handbook rating

  • Plate voltage

    250 V

    ClassA

  • Screen voltage

    150 V

    ClassA

  • Plate current

    10.6 mA

    ClassA

  • Screen current

    4.3 mA

    ClassA

Characteristic

  • Plate resistance

    1000000 ohm

    Published handbook characteristic

  • Transconductance

    5200 µS

    Published handbook characteristic

  • Heater/filament voltage

    3.15 V

    Published heater/filament rating

  • Heater/filament current

    600 mA

    Published heater/filament rating

Data set 02

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Pentode

Capacitance

  • Grid To Plate Capacitance

    0.003 pF

    PentodeConnection

Other

  • Heater Cathode Voltage

    200 V

Data set 03

1965 Sylvania Electronic Tubes Vol3

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristics

  • Plate voltage

    250 V

    PentodeConnection

  • Screen-grid voltage

    125 V

    PentodeConnection

  • Cathode resistor

    100 Ohm

    PentodeConnection

  • Transconductance

    4500 uS

    PentodeConnection

  • Plate resistance

    1500000 Ohm

    PentodeConnection

  • Plate current

    7.6 mA

    PentodeConnection

  • Screen-grid current

    3 mA

    PentodeConnection

  • Triode-connected plate voltage

    250 V

    TriodeConnection

  • Triode-connected amplification factor

    36 ratio

    TriodeConnection

  • Triode-connected plate resistance

    7500 Ohm

    TriodeConnection

Capacitance

  • Grid-to-plate capacitance

    0.0035 pF

    PentodeConnection

  • Input capacitance

    5.5 pF

    PentodeConnection

  • Output capacitance

    5 pF

    PentodeConnection

Data set 04

1965 Westinghouse Data Book

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

  • Heater Voltage

    3.15 V

  • Heater Current

    600 mA

  • ControlledWarmupHeater

    1 boolean

  • Heater Warmup Time

    11 s

  • Transconductance

    5200 uS

  • Plate Resistance

    500000 ohm

  • GridToPlateCapacitanceMaximum

    0.0035 pF

  • Input Capacitance

    5.5 pF

  • Output Capacitance

    5 pF

  • Application

    Wide-band RF/IF and audio voltage amplifier

Other

  • Plate Voltage

    250 V

    PentodeConnection

  • Screen Voltage

    150 V

    PentodeConnection

  • Grid Voltage

    -2 V

    PentodeConnection

  • Plate Current

    10.5 mA

    PentodeConnection

  • Screen Current

    4.2 mA

    PentodeConnection

Data set 05

1966 Tung Sol Electronic Tubes 1 of 4

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

  • Heater voltage

    3.15 V

    Published heater rating

  • Heater current

    600 mA

    Published heater rating

  • Transconductance

    5200 µS

    PentodeConnection

Capacitance

  • Grid-to-plate capacitance

    0.003 pF

    PentodeConnection

  • Input capacitance

    5.5 pF

    PentodeConnection

Other

  • Plate voltage

    250 V

    PentodeConnection

  • Screen voltage

    150 V

    PentodeConnection

  • Plate current

    10.6 mA

    PentodeConnection

  • Screen current

    4.3 mA

    PentodeConnection

Data set 06

1971 RCA HB3 Binder 4 of 7

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristics

  • Current — published value 1

    0

    Published datasheet value; multiple numbers on a row represent separate source limits or conditions.

  • Current — published value 2

    600

    Published datasheet value; multiple numbers on a row represent separate source limits or conditions.

  • Current — published value 3

    0.04

    Published datasheet value; multiple numbers on a row represent separate source limits or conditions.

  • Voltage (AC or Ix) at heater — published value 1

    0

    Published datasheet value; multiple numbers on a row represent separate source limits or conditions.

  • Voltage (AC or Ix) at heater — published value 2

    0

    Published datasheet value; multiple numbers on a row represent separate source limits or conditions.

  • Voltage (ac or dc) at 0.600 A — published value 1

    0 V

    Published datasheet value; multiple numbers on a row represent separate source limits or conditions.

  • Voltage (ac or dc) at 0.600 A — published value 2

    0.6 V

    Published datasheet value; multiple numbers on a row represent separate source limits or conditions.

  • Voltage (ac or dc) at 0.600 A — published value 3

    3.15 V

    Published datasheet value; multiple numbers on a row represent separate source limits or conditions.

  • Warm-up Time (Average)

    11

    Published datasheet value; multiple numbers on a row represent separate source limits or conditions.

  • Voltage (ac or dc) at 0.450 A — published value 1

    0 V

    Published datasheet value; multiple numbers on a row represent separate source limits or conditions.

  • Voltage (ac or dc) at 0.450 A — published value 2

    0.45 V

    Published datasheet value; multiple numbers on a row represent separate source limits or conditions.

  • Voltage (ac or dc) at 0.450 A — published value 3

    3 V

    Published datasheet value; multiple numbers on a row represent separate source limits or conditions.

Data set 07

1975 RCA RC30

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Heater Voltage (ac/dc) 3.15 4.2 6.3

    12.6 V

    Heater Voltage (ac/dc) 3.15 4.2 6.3 12.6 volts

  • Heater Current 0.6 0.45 0.3

    150 mA

    Heater Current 0.6 0.45 0.3 0.15 ampere

  • Plate Voltage 275

    330 V

    Plate Voltage 275 330 volts

  • Plate Dissipation 3.5

    3.5 W

    Plate Dissipation 3.5 3.5 watts

  • For grid-No.2 voltages up to

    165 V

    For grid-No.2 voltages up to 165 volts

  • For grid-No.2 voltages between 165 and

    330 V

    For grid-No.2 voltages between 165 and 330 volts

  • Maximum plate voltage

    330 V

    Published maximum rating

  • Maximum screen-grid voltage

    165 V

    Published maximum rating

Characteristic

  • Grid-No.2 Supply Voltage 100 125

    150 V

    Grid-No.2 Supply Voltage 100 125 150 volts

  • Plate Resistance (Approx.) 0.5 1.5

    1 Mohm

    Plate Resistance (Approx.) 0.5 1.5 1 megohms

  • Plate Current 12.2 5 7.6

    10.6 mA

    Plate Current 12.2 5 7.6 10.6 mA

  • Amplification factor

    36

    Published section characteristic