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Voltage - Dual Triode (similar) ·Triode-Triode

6AQ8

High-mu twin triode designed for RF amplification and self-oscillating mixer service in FM/AM receivers, combining front-end gain and frequency conversion in one envelope.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
B9A
Socket code
B9A
Base pins
9
Nominal heater
6.3 V / 435 mA

Description

High-mu twin triode used as RF amplifier and self-oscillating mixer in FM/AM radio receivers.

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
B9A
Socket code
B9A
Base pins
9
Nominal heater voltage
6.3 V
Nominal heater current
435 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

B9A - Terminal pinout

Electrical assignments shared by every tube using this base designation.

No verified pinout is recorded for this base designation.

Section ratings

2 physical sections, each with unique specifications.

Section 1

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
9700 Ω
Transconductance
0.006 S
Amplification factor
57
Max plate voltage
300 V
Max plate dissipation
2.5 W
Max cathode current
15 mA

Two similar triode sections; represented once under identical-section compression.

Section 2

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
9700 Ω
Transconductance
0.006 S
Amplification factor
57
Max plate voltage
300 V
Max plate dissipation
2.5 W
Max cathode current
15 mA

Second physical triode section; added to align rows with SectionCount.

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

1958 Amperex Industrial

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Plate voltage

    530 V

    Published Amperex table

  • Mixer plate current

    5.2 mA

    Published Amperex table

Characteristic

  • Plate resistance

    9700 ohm

    Published Amperex table

  • Transconductance

    6000 µS

    Published Amperex table

  • Amplification factor

    57

    Published Amperex table

  • Heater/filament voltage

    6.3 V

    Published Amperex table

  • Heater/filament current

    435 mA

    Published Amperex table

  • Mixer plate resistance

    2200 ohm

    Published Amperex table

  • Mixer transconductance

    2300 µS

    Published Amperex table

Data set 02

1959 Rogers

Published operating points and test conditions from this source.

SECTION 1

Triode

Application

  • Application

    RF amplifier / self-oscillating mixer

Data set 03

1961 Ferranti Technical Handbook

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristics

  • Plate voltage

    250 V

    EachSection

  • Control-grid voltage

    -2.2 V

    EachSection

  • Plate current

    10 mA

    EachSection

  • Amplification factor

    57 ratio

    EachSection

  • Transconductance

    6000 uS

    EachSection

  • Equivalent noise resistance

    500 Ohm

    RFAmplifier

  • Input resistance

    6000 Ohm

    RFAmplifier;f=100MHz

Other

  • Plate supply voltage

    250 V

    RFAmplifier

  • Plate voltage

    240 V

    RFAmplifier

  • Plate current

    10 mA

    RFAmplifier

  • Transconductance

    6200 uS

    RFAmplifier

  • Plate resistance

    9400 Ohm

    RFAmplifier

  • Conversion conductance

    2700 uS

    SelfOscillatingMixer

  • Plate resistance

    20000 Ohm

    SelfOscillatingMixer

Capacitance

  • Input capacitance

    3 pF

    EachSection

  • Output capacitance

    1.2 pF

    EachSection

  • Plate-to-grid capacitance

    1.6 pF

    EachSection

Data set 04

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

    435 mA

    Published heater rating

  • Amplification factor

    57

    RFAmplifier

  • Plate resistance

    9700 ohm

    RFAmplifier

  • Transconductance

    6000 µS

    RFAmplifier

  • Mixer plate resistance

    2200 ohm

    MixerSection

  • Mixer transconductance

    2300 µS

    MixerSection

Other

  • RF-amplifier plate voltage

    230 V

    RFAmplifier

  • Control-grid bias

    -2 V

    RFAmplifier

  • RF-amplifier plate current

    10 mA

    RFAmplifier

  • Mixer plate voltage

    190 V

    MixerSection

  • Mixer plate current

    5.2 mA

    MixerSection

Data set 05

1975 RCA RC30

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Heater Voltage (ac/dc)

    6.3 V

    Published in approved ECC85 target datasheet entry; Section1

  • Heater Current

    436 mA

    Published in approved ECC85 target datasheet entry; Section1

  • Plate Supply Voltage

    560 V

    Published in approved ECC85 target datasheet entry; Section1

  • Plate Voltage

    300 V

    Published in approved ECC85 target datasheet entry; Section1

  • Grid Voltage, Negative-bias value

    100 V

    Published in approved ECC85 target datasheet entry; Section1

  • Cathode Current

    15 mA

    Published in approved ECC85 target datasheet entry; Section1

  • For either plate

    2.5 W

    Published in approved ECC85 target datasheet entry; Section1

  • For both plates with both units operating

    4.5 W

    Published in approved ECC85 target datasheet entry; Section1

  • Plate Voltage

    250 V

    Published in approved ECC85 target datasheet entry; Section1

  • Grid Voltage. Negative-bias value

    2.3 V

    Published in approved ECC85 target datasheet entry; Section1

  • Plate Current

    10 mA

    Published in approved ECC85 target datasheet entry; Section1

  • Transconductance

    5900 µS

    Published in approved ECC85 target datasheet entry; Section1

  • Plate Supply Voltage 250

    250 V

    Published in approved ECC85 target datasheet entry; Section1

  • Plate Resistor 1800

    12000 Ω

    Published in approved ECC85 target datasheet entry; Section1

  • Grid Resistor —

    -1 MΩ

    Published in approved ECC85 target datasheet entry; Section1

  • Grid Voltage

    -2 V

    Published in approved ECC85 target datasheet entry; Section1

  • RMS Oscillator Voltage —

    -3 V

    Published in approved ECC85 target datasheet entry; Section1

  • Cathode-Bias Resistor

    200 Ω

    Published in approved ECC85 target datasheet entry; Section1

  • Plate Resistance (Approx.) 9700

    22000 Ω

    Published in approved ECC85 target datasheet entry; Section1

  • Input Resistance at frequency of

    100 MHz

    Published in approved ECC85 target datasheet entry; Section1

  • Input Resistance at frequency of 100 MHz 6000

    15000 Ω

    Published in approved ECC85 target datasheet entry; Section1

  • Plate Current 10

    5.2 mA

    Published in approved ECC85 target datasheet entry; Section1

  • Grid-Circuit Resistance

    1 MΩ

    Published in approved ECC85 target datasheet entry; Section1

  • Resistance between Cathode and Heater

    20000 Ω

    Published in approved ECC85 target datasheet entry; Section1

Capacitance

  • Grid to Plate 1.6

    1.5 pF

    Published in approved ECC85 target datasheet entry; Section1

  • Cathode to Plate 0.18

    0.18 pF

    Published in approved ECC85 target datasheet entry; Section1

  • Grid to Cathode, Heater, and Internal Shield . . 3

    3 pF

    Published in approved ECC85 target datasheet entry; Section1

  • Plate to Cathode, Heater, and Internal Shield . . 1.2

    1.2 pF

    Published in approved ECC85 target datasheet entry; Section1