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Voltage - Dual Triode (similar high frequency) ·Triode-Triode

4BZ7

Medium-mu twin triode intended for VHF television tuner cascode amplification and push-pull cathode-drive RF amplifier service, providing two high-frequency triode sections in one envelope.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
9AJ
Socket code
B9A
Base pins
9
Nominal heater
4.2 V / 600 mA

Description

Medium-mu twin triode used as a cascode amplifier in VHF television tuners and in push-pull cathode-drive RF amplifiers.

Socket description

Small-button Noval 9-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
9AJ
Socket code
B9A
Base pins
9
Nominal heater voltage
4.2 V
Nominal heater current
600 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

9AJ - Terminal pinout

Electrical assignments shared by every tube using this base designation.

TerminalSectionConnectionEvidence
PIN12PBP — Plate (Anode)

Numbered source electrode preserved; manufacturer verification pending

Unverified

EIA Base Connections, printed page 131, 9AJ

PIN22G1BG1 — Control Grid

Source label preserved; pending confirmation

Unverified

EIA Base Connections, printed page 131, 9AJ

PIN32KBK — Cathode

Numbered source electrode preserved; manufacturer verification pending

Unverified

EIA Base Connections, printed page 131, 9AJ

PIN4H—H — Heater

Numbered source electrode preserved; manufacturer verification pending

Unverified

EIA Base Connections, printed page 131, 9AJ

PIN5H—H — Heater

Numbered source electrode preserved; manufacturer verification pending

Unverified

EIA Base Connections, printed page 131, 9AJ

PIN61PAP — Plate (Anode)

Numbered source electrode preserved; manufacturer verification pending

Unverified

EIA Base Connections, printed page 131, 9AJ

PIN71G1AG1 — Control Grid

Source label preserved; pending confirmation

Unverified

EIA Base Connections, printed page 131, 9AJ

PIN81KAK — Cathode

Numbered source electrode preserved; manufacturer verification pending

Unverified

EIA Base Connections, printed page 131, 9AJ

PIN9ISAIS — Internal Screen

Numbered source electrode preserved; manufacturer verification pending

Unverified

EIA Base Connections, printed page 131, 9AJ

Section ratings

2 physical sections, each with unique specifications.

Section 1

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
5600 Ω
Transconductance
0.0068 S
Amplification factor
38
Max plate voltage
250 V
Max plate dissipation
2 W
Max cathode current
20 mA
Rectifier warm-up time
11 s

Published ratings and characteristics promoted where applicable.

Section 2

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
5600 Ω
Transconductance
0.0068 S
Amplification factor
38
Max plate voltage
250 V
Max plate dissipation
2 W
Max cathode current
20 mA

Second physical triode section; electrically identical twin section.

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

Triode

Capacitance

  • Input Capacitance

    2.5 pF

    EachUnit

  • Output Capacitance

    1.35 pF

    EachUnit

  • Grid-Plate Capacitance

    1.15 pF

    EachUnit

Other

  • Plate Voltage

    150 V

    ClassA;EachUnit

  • Cathode Bias Resistor

    220 ohm

    ClassA;EachUnit

  • Plate Current

    10 mA

    ClassA;EachUnit

Data set 02

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristic

  • Heater Warmup Time

    11 s

Data set 03

1965 Westinghouse Data Book

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristics

  • Heater Voltage

    4.2 V

  • Heater Current

    600 mA

Other

  • Maximum Plate Voltage

    250 V

  • Maximum Plate Dissipation

    2 W

Data set 04

1966 Tung Sol Electronic Tubes 1 of 4

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Plate voltage

    150 V

    EachSection

  • Plate current

    10 mA

    EachSection

Characteristic

  • Transconductance

    6500 µS

    EachSection

  • Plate resistance

    6400 Ω

    EachSection

  • Amplification factor

    42

    EachSection

Data set 05

1971 RCA HB3 Binder 4 of 7

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Heater Current

    560 mA to 640 mA

    Published nominal ± tolerance

  • Heater Voltage

    4.2 V

    At heater current 0.6 A

  • Warm-Up Time

    11 s

    Average

  • Plate Voltage

    150 V

    Inherited from explicitly referenced 6-volt parent type; heater variant

  • Cathode Bias Resistor

    220 Ω

    Inherited from explicitly referenced 6-volt parent type; heater variant

  • Plate Current

    10 mA

    Inherited from explicitly referenced 6-volt parent type; heater variant

Characteristics

  • Amplification Factor

    36

    Inherited from explicitly referenced 6-volt parent type; heater variant

  • Plate Resistance

    5300 Ω

    Inherited from explicitly referenced 6-volt parent type; heater variant

  • Transconductance

    6800 µS

    Inherited from explicitly referenced 6-volt parent type; heater variant

Data set 06

1975 RCA RC30

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Heater Voltage (ac/dc) 4.2 5.6

    6.3 V

    Published in approved 6BZ7 target datasheet entry; Section1

  • Heater Current 0.45

    400 mA

    Published in approved 6BZ7 target datasheet entry; Section1

  • Cathode Current

    20 mA

    Published in approved 6BZ7 target datasheet entry; Section1

  • Plate Dissipation

    2 W

    Published in approved 6BZ7 target datasheet entry; Section1

  • Plate Supply Voltage

    150 V

    Published in approved 6BZ7 target datasheet entry; Section1

  • Cathode-Bias Resistor

    220 Ω

    Published in approved 6BZ7 target datasheet entry; Section1

  • Plate Resistance (Approx.)

    5900 Ω

    Published in approved 6BZ7 target datasheet entry; Section1

  • Transconductance

    6400 µS

    Published in approved 6BZ7 target datasheet entry; Section1

  • Plate Current

    9 mA

    Published in approved 6BZ7 target datasheet entry; Section1

  • Grid-Circuit Resistance

    0.5 MΩ

    Published in approved 6BZ7 target datasheet entry; Section1

  • * Rating may be high as

    300 V

    Published in approved 6BZ7 target datasheet entry; Section1

Capacitance

  • Grid to Plate 1.2

    1.2 pF

    Published in approved 6BZ7 target datasheet entry; Section1

  • —

    -5 pF

    Published in approved 6BZ7 target datasheet entry; Section1

  • Plate to Grid, Heater, and Internal Shield

    2.2 pF

    Published in approved 6BZ7 target datasheet entry; Section1

  • Plate to Cathode 0.12

    0.12 pF

    Published in approved 6BZ7 target datasheet entry; Section1

  • Heater to Cathode 2.6

    2.6 pF

    Published in approved 6BZ7 target datasheet entry; Section1

  • * Rating: may be high as

    300 V

    Published in approved 6BZ7 target datasheet entry; Section1

Characteristic

  • For plate current of 100

    -6.5 V

    Published in approved 6BZ7 target datasheet entry; Section1