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Voltage - Pentode Sharp Cutoff (single) ·Pentode

6AU6A

Sharp-cutoff 6AU6-family pentode for fixed-gain RF and IF voltage amplification.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
7BK
Socket code
B7G
Base pins
7
Nominal heater
6.3 V / 300 mA

Description

Sharp-cutoff pentode explicitly identified by the 7543 source as electrically identical except for the 7543 controlled-hum characteristic.

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
6.3 V
Nominal heater current
300 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
Max plate voltage
330 V
Max screen voltage
150 V
Max plate dissipation
3.5 W
Max screen dissipation
0.75 W
Max cathode current
25 mA
Rectifier max heater-cathode voltage
200 V

Promoted from published ratings/characteristics; identical repeated sections compressed where applicable.

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

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 02

1965 Westinghouse Data Book

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

  • HeaterOrFilamentVoltage

    6.3 V

  • HeaterOrFilamentCurrent

    300 mA

  • ControlledWarmupHeater

    1 boolean

  • Heater Warmup Time

    11 s

  • Plate Voltage

    250 V

  • Screen Voltage

    150 V

  • Grid Voltage

    -2 V

  • Plate Current

    10.5 mA

  • Screen Current

    4.2 mA

  • Transconductance

    5200 uS

  • Plate Resistance

    500000 ohm

  • GridToPlateCapacitanceMaximum

    0.0035 pF

  • Input Capacitance

    5.5 pF

  • Output Capacitance

    5 pF

  • TriodeConnectedAmplificationFactor

    36

  • TriodeConnectedPlateResistance

    7500 ohm

    TriodeConnection

Data set 03

1966 Tung Sol Electronic Tubes 1 of 4

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

  • Heater voltage

    6.3 V

    Published table

  • Heater current

    300 mA

    Published table

  • Plate resistance

    1000000 ohm

    Published table

  • Transconductance

    5200 µS

    Published table

  • Amplification factor

    36

    Published table

  • Heater warm-up time

    11 s

    Published table

Other

  • Plate voltage

    250 V

    RFAmplifier

  • Screen voltage

    150 V

    RFAmplifier

  • Plate current

    10.6 mA

    RFAmplifier

  • Screen current

    4.3 mA

    RFAmplifier

Data set 04

1971 RCA HB3 Binder 3 of 7

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Heater voltage

    6.3 V

  • Heater current

    300 mA

  • Plate voltage

    250 V

    ClassA

  • Screen voltage

    150 V

    ClassA

  • Grid voltage

    -2 V

    ClassA

  • Plate current

    10.5 mA

    ClassA

  • Screen current

    3.5 mA

    ClassA

  • Heater warm-up time

    11 s

    ControlledWarmup

Characteristic

  • Transconductance

    5200 uS

    ClassA

  • Plate resistance

    500000 ohm

    ClassA

Capacitance

  • Grid-to-plate capacitance

    0.0035 pF

    WithShield