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8AU8

Television triode-pentode for video/IF amplification and synchronization or sweep service.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: 9DX
Socket code: B9A
Base pins: 9
Nominal heater: 8.4 V / 450 mA

Description

The 8AU8 combines a sharp-cutoff pentode with a medium-mu triode for series-heater television receivers; the pentode suits video/IF service and the triode sync, clipper or sweep-oscillator functions.

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: 9DX
Socket code: B9A
Base pins: 9
Nominal heater voltage: 8.4 V
Nominal heater current: 450 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

9DX - Terminal pinout

Electrical assignments shared by every tube using this base designation.

Terminal	Section	Connection	Evidence
PIN12K	B	K — Cathode EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 131, 9DX
PIN22G1	B	G1 — Control Grid EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 131, 9DX
PIN32P	B	P — Plate (Anode) EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 131, 9DX
PIN4H	—	H — Heater EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 131, 9DX
PIN5H	—	H — Heater EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 131, 9DX
PIN61G3	A	G3 — Suppressor GridGroup 9DX6 EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 131, 9DX
PIN6IS	A	IS — Internal ScreenGroup 9DX6 EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 131, 9DX
PIN61K	A	K — CathodeGroup 9DX6 EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 131, 9DX
PIN71G1	A	G1 — Control Grid EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 131, 9DX
PIN81G2	A	G2 — Screen Grid EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 131, 9DX
PIN91P	A	P — Plate (Anode) EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 131, 9DX

Section ratings

2 physical sections, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 150000 Ω
Transconductance: 0.007 S
Max plate voltage: 300 V
Max screen voltage: 300 V
Max plate dissipation: 3 W
Max screen dissipation: 1 W
Rectifier max heater-cathode voltage: 200 V
Rectifier warm-up time: 11 s

Published promoted fields populated semantically; identical repeated sections compressed.

Section 2

Triode

X-ray radiationInterelectrode capacitances

Plate resistance: 8200 Ω
Transconductance: 0.0049 S
Amplification factor: 40
Max plate voltage: 300 V
Max plate dissipation: 2.5 W
Rectifier max heater-cathode voltage: 200 V
Rectifier warm-up time: 11 s

Published promoted fields populated semantically; identical repeated sections compressed.

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

Characteristic

Heater voltage
8.4 V
Rated heater condition
Heater current
450 mA
Rated heater condition

SECTION 2

Triode

Characteristic

Heater voltage
8.4 V
Rated heater condition
Heater current
450 mA
Rated heater condition

Other

Current
450 mA
Current ..................... 0.60 0.45 Ampere Grid 2 Voltage ..... See Grid 2 Input
Warm-upTime(Approx.)A
11 s
Warm-upTime(Approx.)A ......... 11 11 Seconds Rating Chart
Base,,,
125 V
Base,,,................, E9-I) Grid 2 Voltage ................-- 125 Volts

Data set 02

1966 Tung Sol Electronic Tubes 2 of 4

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Plate_voltage
200 V
VideoAmplifier
Screen_voltage
125 V
VideoAmplifier
Cathode_bias_resistor
82 ohm
VideoAmplifier

Characteristic

Plate_current
15 mA
VideoAmplifier
Screen_current
3.4 mA
VideoAmplifier
Transconductance
7000 uS
VideoAmplifier

Capacitance

Grid-to-plate capacitance
0.044 pF
Input capacitance
7.5 pF
Output capacitance
3.4 pF

SECTION 2

Triode

Other

Plate_voltage
150 V
SyncAmplifier
Cathode_bias_resistor
150 ohm
SyncAmplifier
Heater_warmup_time
11 s
SyncAmplifier

Characteristic

Plate_current
9 mA
SyncAmplifier
Amplification_factor
40
SyncAmplifier
Plate_resistance
6100 ohm
SyncAmplifier
Transconductance
4900 uS
SyncAmplifier

Capacitance

Grid-to-plate capacitance
2.2 pF
Input capacitance
2.6 pF
Output capacitance
0.34 pF

Data set 03

1971 RCA HB3 Binder 5 of 7

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Heater voltage nominal
8.4 V
Heater current nominal
450 mA
PLATE VOLTAGE
300 V
Published source row
PLATE VOLTAGE (value 2)
300 V
Published source row
GRID-No
2
Published source row
SUPPLY VOLTAGE
300 V
Published source row
GRID-No
2
Published source row
GRID-No
2
Published source row
For grid-No
2
Published source row
For grid-No
2
Published source row
PLATE DISSIPATION
2.5 W
Published source row
PLATE DISSIPATION (value 2)
3 W
Published source row

Characteristics

Current
30 mA
Published table column
Warm-up time (Average)
11 s
Published source row
Plate Supply Voltage
150 V
Published source row
Plate Supply Voltage (value 2)
200 V
Published source row
Grid-No
2 V
Published source row
Grid-No (value 2)
125 V
Published source row
Cathode Resistor
150 ohm
Published source row
Cathode Resistor (value 2)
82 ohm
Published source row
Plate Resistance (Approx )
8200 ohm
Published source row
Plate Resistance (Approx ) (value 2)
150000 ohm
Published source row
Transconductance
4900 µS
Published source row
Transconductance (value 2)
7000 µS
Published source row
Plate Current
9 mA
Published source row
Plate Current (value 2)
15 mA
Published source row
Grid-No
2 mA
Published source row
Grid-No (value 2)
3.4 mA
Published source row

SECTION 2

Triode

Other

Heater voltage nominal
8.4 V
Heater current nominal
450 mA

Characteristics

Current
450 mA
Published table column
Warm-up time (Average)
11 s
Published source row