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Voltage Pentode - Sharp Cutoff (single) ·Pentode

6AK5

Miniature high-frequency pentode designed for low-noise RF and IF voltage amplification. Its compact construction and reduced noise make it particularly useful in sensitive receiver front-end signal stages.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
7BD
Socket code
B7G
Base pins
7
Nominal heater
6.3 V / 175 mA

Description

Miniature high-frequency pentode for low-noise RF and IF voltage amplification.

Socket description

Miniature 7-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
7BD
Socket code
B7G
Base pins
7
Nominal heater voltage
6.3 V
Nominal heater current
175 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

7BD - Terminal pinout

Electrical assignments shared by every tube using this base designation.

TerminalSectionConnectionEvidence
PIN1G1AG1 — Control Grid

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 128, 7BD

PIN2G3AG3 — Suppressor GridGroup 7BD2

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 128, 7BD

PIN2ISAIS — Internal ScreenGroup 7BD2

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 128, 7BD

PIN2KAK — CathodeGroup 7BD2

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 128, 7BD

PIN3H—H — Heater

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 128, 7BD

PIN4H—H — Heater

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 128, 7BD

PIN5PAP — Plate (Anode)

EIA chart transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 128, 7BD

PIN6G2AG2 — Screen Grid

EIA chart transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 128, 7BD

PIN7G3AG3 — Suppressor GridGroup 7BD7

EIA chart transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 128, 7BD

PIN7ISAIS — Internal ScreenGroup 7BD7

EIA chart transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 128, 7BD

PIN7KAK — CathodeGroup 7BD7

EIA chart transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 128, 7BD

Section ratings

1 physical section, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances
Plate resistance
300000 Ω
Transconductance
0.005 S
Max plate voltage
180 V
Max screen voltage
140 V
Max plate dissipation
1.7 W
Max screen dissipation
0.5 W
Max cathode current
18 mA

Promoted fields mapped from printed maximum-rating and characteristic headings; additional published values preserved 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

1956 Western Electric Tubes

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

  • HeaterOrFilamentVoltage

    6.3 V

  • HeaterOrFilamentCurrent

    175 mA

  • Transconductance

    5000 uS

    Typical

Data set 02

1958 Brimar Radio Valve No 7

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

  • Operating Frequency Maximum

    400 MHz

    Amplifier use

Other

  • Plate Voltage

    180 V

  • Plate Current

    7.7 mA

  • Screen Voltage

    120 V

Data set 03

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Maximum plate voltage

    180 V

    Published handbook rating

  • Maximum screen voltage

    140 V

    Published handbook rating

  • Plate voltage

    180 V

    ClassA

  • Screen voltage

    120 V

    ClassA

  • Plate current

    7.7 mA

    ClassA

  • Screen current

    2.4 mA

    ClassA

Characteristic

  • Plate resistance

    500000 ohm

    Published handbook characteristic

  • Transconductance

    5100 µS

    Published handbook characteristic

  • Heater voltage

    6.3 V

    Published heater rating

  • Heater current

    175 mA

    Published heater rating

Capacitance

  • Input capacitance

    4 pF

    Published capacitance column

  • Output capacitance

    2.8 pF

    Published capacitance column

  • Grid-to-plate capacitance

    0.02 pF

    Published capacitance column

Data set 04

1961 Ferranti Technical Handbook

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

  • HeaterOrFilamentVoltage

    6.3 V

  • HeaterOrFilamentCurrent

    175 mA

  • MaximumOperatingFrequency

    400 MHz

    WideBandAmplifier

Data set 05

1963 Amperex Condensed

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

  • Heater voltage

    6.3 V

    Published rating

  • Heater current

    175 mA

    Published rating

  • Transconductance

    5000 µS

    Published table

  • Published characteristic value

    340

    Published table

Other

  • Plate voltage

    120 V

    Published table

  • Screen voltage

    120 V

    Published table

  • Cathode resistor

    100 ohm

    Published table

  • Published current value

    2.5 mA

    Published table

Data set 06

1966 Tung Sol Electronic Tubes 1 of 4

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Plate voltage

    120 V

    ClassA

  • Screen voltage

    120 V

    ClassA

  • Plate current

    7.5 mA

    ClassA

  • Screen current

    2.5 mA

    ClassA

  • Application

    Sharp-cutoff high-frequency voltage amplifier

    Section1

Characteristic

  • Plate resistance

    0.3 MΩ

    Condition1

  • Transconductance

    5000 µS

    Condition1

  • Plate resistance

    0.5 MΩ

    Condition2

  • Transconductance

    5100 µS

    Condition2

Data set 07

1967 Mullard Receiving and Amplifying Valves

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • ( in 4.0

    4 pF

    Published in approved EF95 target datasheet entry; Section1

  • Cout 2.2

    3.1 pF

    Published in approved EF95 target datasheet entry; Section1

  • ( a - g'! 23 <

    0.02 pF

    Published in approved EF95 target datasheet entry; Section1

  • Ch- k 2

    2 pF

    Published in approved EF95 target datasheet entry; Section1

  • Cin 2.7

    2.8 pF

    Published in approved EF95 target datasheet entry; Section1

  • Cou t 4.2

    5.1 pF

    Published in approved EF95 target datasheet entry; Section1

  • ( ( a- g 1.4

    1.4 pF

    Published in approved EF95 target datasheet entry; Section1

  • gm 5.0

    5.1 mA

    Published in approved EF95 target datasheet entry; Section1

  • Pg2 max

    500 mW

    Published in approved EF95 target datasheet entry; Section1

  • T h ul h max

    170 °C

    Published in approved EF95 target datasheet entry; Section1

Data set 08

1968 Mazda Belvu

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • HeaterVoltageNominal

    6.3 V

    Nominal

  • HeaterCurrentNominal

    175 mA

    Nominal

  • Maximum Plate Voltage

    200 V

  • Maximum Screen Voltage

    155 V

  • Maximum Plate Dissipation

    1.7 W

  • Maximum Screen Dissipation

    0.55 W

  • Maximum Cathode Current

    20 mA

Characteristic

  • Transconductance

    5000 µS

    Typical

  • Plate Resistance

    340000 ohm

    Typical

Data set 09

1975 RCA RC30

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • 100 /iA

    -5.4 V

    Published in approved EF95 target datasheet entry; Section1

  • For fixed-bias operation 0.5

    0.1 MΩ

    Published in approved EF95 target datasheet entry; Section1

  • For cathode-bias operation 1

    0.25 MΩ

    Published in approved EF95 target datasheet entry; Section1

  • 7BD cies up to

    400 MHz

    Published in approved EF95 target datasheet entry; Section1

  • Heater Voltage (ac/dc)

    6.3 V

    Published in approved EF95 target datasheet entry; Section1

  • Heater Current

    175 mA

    Published in approved EF95 target datasheet entry; Section1

  • Plate Voltage

    180 V

    Published in approved EF95 target datasheet entry; Section1

  • Grid-No.2 Supply Voltage

    180 V

    Published in approved EF95 target datasheet entry; Section1

  • Grid-No.l Voltage, Positive-bias value

    0 V

    Published in approved EF95 target datasheet entry; Section1

  • Plate Dissipation

    1.7 W

    Published in approved EF95 target datasheet entry; Section1

  • For grid-No. 2 voltages up to

    90 V

    Published in approved EF95 target datasheet entry; Section1

  • For grid-No. 2 voltages up to 90 volts

    0.5 W

    Published in approved EF95 target datasheet entry; Section1

  • For grid-No.2 voltages between 90 and

    180 V

    Published in approved EF95 target datasheet entry; Section1

  • Cathode Current

    18 mA

    Published in approved EF95 target datasheet entry; Section1

  • Grid-No.2 Supply Voltage 120

    120 V

    Published in approved EF95 target datasheet entry; Section1

Capacitance

  • Internal Shield

    4 pF

    Published in approved EF95 target datasheet entry; Section1

  • Internal Shield

    2.8 pF

    Published in approved EF95 target datasheet entry; Section1

Characteristic

  • Cathode- Bias Resistor 180

    180 Ω

    Published in approved EF95 target datasheet entry; Section1

  • Plate Resistance tApprox.) 0.3

    0.5 MΩ

    Published in approved EF95 target datasheet entry; Section1

  • Transconductanee 5000

    5100 µS

    Published in approved EF95 target datasheet entry; Section1

  • Plate Current 7.5

    7.7 mA

    Published in approved EF95 target datasheet entry; Section1

  • Grid-No. 2 Current 2.5

    2.4 mA

    Published in approved EF95 target datasheet entry; Section1

Data set 10

2026 Western Electric 400s

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

  • Plate Current . . E, = E., =

    120 volts

    Plate Current . . E, = E., = 120 volts; . 7.5 milliamperes

  • Transconductance . { Cathode-Bias Resistor =

    200 micromhos

    Transconductance . { Cathode-Bias Resistor = 200 chms } . . 5000 micromhos

  • Heater Voltage, A-CorD-C

    6.3 volts

    Heater Voltage, A-CorD-C. . . . . . . . . . . . . 6.3 volts

  • Heater Current

    175 milliamperes

    Heater Current . . . . . . . . . . . . . . .. 175 milliamperes

  • Plate Voltage

    180 volts

    Plate Voltage . . . . . . . . . . . . . . . . . 180 volts

  • Screen Grid Voltage

    140 volts

    Screen Grid Voltage . . . . . . . . . . . . . . . 140 volts

  • Cathode Current

    18 milliamperes

    Cathode Current . . . . . . . . . . . . . . .. 18 milliamperes

  • Bulb Temperature

    120 centigrade

    Bulb Temperature. . . . . . . . . . . . ... 120 centigrade

  • Plate Voltage

    120 volts

    Plate Voltage . . . . . . . . . . . . 120 150 180 volts

  • Screen Grid Voltage

    120 volts

    Screen Grid Voltage . . . . . . . . . . 120 140 120 volts

  • Cathode-Bias Resistor

    200 ohms

    Cathode-Bias Resistor . . . . . . . . . 200 330 200 ohms

  • Plate Current

    75 milliamperes

    PlateCurrent. . . . . . . . . . . . 75 6.6 7.7 milliamperes

  • Screen Grid Current

    25 milliamperes

    Screen Grid Current. . . . . . . . . . 25 2.1 24 milliamperes .

  • Plate Resistance

    0.3 megohm

    Plate Resistance . . . . . . . . . . . 0.30 6.40 045 megohm |

  • Transconductanee

    5000 micromhos

    Transconductanee . . . . . . . . . . 5000 4500 5100 micromhos

  • Plate Current of

    10 Microamperes

    Plate Current of 10 Microamperes . . . . . —6.8 —7.8 —06.9 volts

  • SCREEN GRID VOLTAGE=

    120 VOLTS

    SCREEN GRID VOLTAGE=120 VOLTS . SCREEN GRID VOLTAGE=120 VOLTS

Other

  • Plate Dissipation

    1.7 watts

    Plate Dissipation . . . . . . . . . . . . . . . . 1.7 watts

  • Sereen Grid Dissipation

    0.5 watt

    Sereen Grid Dissipation . . . . . . . . . . . . . . 0.5 watt