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

6DJ8

High-transconductance medium-mu twin triode designed as a low-noise VHF cascode amplifier for color and monochrome television tuners and related high-frequency front ends.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
9AJ
Socket code
B9A
Base pins
9
Nominal heater
6.3 V / 365 mA

Description

Medium-mu industrial twin triode used as a cascode amplifier in VHF color and black-and-white television tuners.

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
6.3 V
Nominal heater current
365 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
2650 Ω
Transconductance
0.0125 S
Amplification factor
33
Max plate voltage
130 V
Max plate dissipation
1.8 W
Max cathode current
25 mA

Published typical operating conditions, characteristics and descriptive application reviewed.

Section 2

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
2650 Ω
Transconductance
0.0125 S
Amplification factor
33
Max plate voltage
130 V
Max plate dissipation
1.8 W
Max cathode current
25 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

1963 Amperex Condensed

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristic

  • Heater voltage

    6.3 V

    Published heater rating

  • Heater current

    365 mA

    Published heater rating

  • Amplification factor

    33

    CascodeRF

  • Plate resistance

    2650 ohm

    CascodeRF

  • Transconductance

    12500 µS

    CascodeRF

Other

  • Plate voltage

    90 V

    CascodeRF

  • Control-grid bias

    -1.3 V

    CascodeRF

  • Plate current

    15 mA

    CascodeRF

Data set 02

1965 Westinghouse Data Book

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Plate voltage maximum

    130 V

  • Cathode current maximum

    20 mA

  • Plate dissipation maximum

    1.8 W

Capacitance

  • Grid-to-plate capacitance per section

    1.4 pF

  • Input capacitance per section

    3.3 pF

Characteristics

  • Plate resistance

    2600 ohm

  • Transconductance

    12500 uS

  • Amplification factor

    33

Application

  • Application

    Low-noise VHF cascode amplifier

Data set 03

1975 RCA RC30

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Load Resistance 2000

    4000 Ω

    Published in approved ECC88 target datasheet entry; Section1

  • TotalHarmonic Distortion .... 10

    10 %

    Published in approved ECC88 target datasheet entry; Section1

  • Maximum-Signal Power Output 2.1

    3.8 W

    Published in approved ECC88 target datasheet entry; Section1

  • For fixed-bias operation

    0.1 MΩ

    Published in approved ECC88 target datasheet entry; Section1

  • For cathode-bias operation

    0.5 MΩ

    Published in approved ECC88 target datasheet entry; Section1

  • Heater Voltage (ac/dc)

    6.3 V

    Published in approved ECC88 target datasheet entry; Section1

  • Heater Current

    365 mA

    Published in approved ECC88 target datasheet entry; Section1

  • Peak value

    -150 V

    Published in approved ECC88 target datasheet entry; Section1

  • Average value 50

    -130 V

    Published in approved ECC88 target datasheet entry; Section1

  • Plate Supply Voltage

    130 V

    Published in approved ECC88 target datasheet entry; Section1

  • Cathode Current

    25 mA

    Published in approved ECC88 target datasheet entry; Section1

  • Plate Dissipation

    1.8 W

    Published in approved ECC88 target datasheet entry; Section1

  • Negative Grid "Voltage

    50 V

    Published in approved ECC88 target datasheet entry; Section1

  • Plate Supply Voltage (cold condition)

    550 V

    Published in approved ECC88 target datasheet entry; Section1

  • Plate Current

    15 mA

    Published in approved ECC88 target datasheet entry; Section1

  • Equivalent Noise Resistance

    300 Ω

    Published in approved ECC88 target datasheet entry; Section1

  • Grid-Circuit Resistance

    1 MΩ

    Published in approved ECC88 target datasheet entry; Section1

  • Heater to Cathode Circuit Resistance

    0.02 MΩ

    Published in approved ECC88 target datasheet entry; Section1

Capacitance

  • Grid to Plate 1.4

    1.4 pF

    Published in approved ECC88 target datasheet entry; Section1

  • Grid to Cathode, Heater, and Internal Shield

    3.3 pF

    Published in approved ECC88 target datasheet entry; Section1

  • Cathode to Grid, Heater, and Internal Shield

    6 pF

    Published in approved ECC88 target datasheet entry; Section1

  • Plate to Cathode, Heater, and Internal Shield

    1.8 pF

    Published in approved ECC88 target datasheet entry; Section1

  • Plate to Grid, Heater, and Internal Shield

    2.8 pF

    Published in approved ECC88 target datasheet entry; Section1

  • Plate to Cathode

    1.8 pF

    Published in approved ECC88 target datasheet entry; Section1

  • Heater to Cathode

    2.7 pF

    Published in approved ECC88 target datasheet entry; Section1

  • Grid to Heater

    0.13 pF

    Published in approved ECC88 target datasheet entry; Section1

  • Plate of Unit No. 1 to Plate of Unit No. 2

    0.045 pF

    Published in approved ECC88 target datasheet entry; Section1

  • Grid of Unit No. 2 to Plate of Unit No. 1

    0.005 pF

    Published in approved ECC88 target datasheet entry; Section1