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Voltage Radio Detector Converter ·Pentode-Triode

9A8

Medium-mu triode and sharp-cutoff pentode for combined VHF television oscillator and mixer service.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: 7AE
Socket code: B9A
Base pins: 9
Nominal heater: 9 V / 300 mA

Description

Medium-mu triode and sharp-cutoff pentode for combined VHF television oscillator and mixer service.

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: 7AE
Socket code: B9A
Base pins: 9
Nominal heater voltage: 9 V
Nominal heater current: 300 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

7AE - 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: 4000 Ω
Transconductance: 0.005 S
Amplification factor: 20
Max plate voltage: 250 V
Max plate dissipation: 1.5 W
Max cathode current: 14 mA

Triode section.

Section 2

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 400000 Ω
Transconductance: 0.0062 S
Max plate voltage: 250 V
Max screen voltage: 175 V
Max plate dissipation: 1.7 W
Max screen dissipation: 0.5 W
Max cathode current: 14 mA

Pentode section; 550-V screen rating is the published no-current condition, with lower current-dependent limits retained as parameters.

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

1961 Ferranti Technical Handbook

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristics

Plate Voltage
100 V
Plate Current
14 mA
Transconductance
5000 uS
Plate Resistance
4000 ohm
Amplification Factor
20 ratio

SECTION 2

Pentode

Characteristics

Plate Voltage
170 V
Screen Voltage
170 V
Plate Current
10 mA
Screen Current
2.8 mA
Transconductance
6200 uS
Plate Resistance
400000 ohm

Other

Conversion Transconductance
2100 uS
FrequencyChanger

Data set 02

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Heater voltage
9 V
Heater current
300 mA

Characteristic

Plate current
14 mA
TriodeSection

Capacitance

Input capacitance
2.5 pF
TriodeSection

SECTION 2

Pentode

Capacitance

Input capacitance
5.5 pF
PentodeSection
Output capacitance
3.8 pF
PentodeSection

Other

Grid-2 voltage maximum
175 V
Ik=14mA
Grid-2 voltage maximum
200 V
Ik<10mA
Grid-2 voltage maximum
550 V
NoCurrent

Characteristic

Conversion conductance
2200 uS
MixerOperatingPoint1
Conversion conductance
2100 uS
MixerOperatingPoint2

Data set 03

1963 Amperex Condensed

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Heater voltage
9 V
Section1
Heater current
300 mA
Section1
Electrical reference
See 6BL8 / ECF80
OscillatorMixer

SECTION 2

Pentode

Other

Electrical reference
See 6BL8 / ECF80
OscillatorMixer

Data set 04

1966 Tung Sol Electronic Tubes 2 of 4

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristics

Plate Voltage
100 V
Grid 1 Voltage
-2 V
Plate Current
14 mA

Other

Conversion Conductance
2200 uS
Mixer

SECTION 2

Pentode

Characteristics

Plate Voltage
170 V
Screen Voltage
170 V
Grid 1 Voltage
-2 V
Plate Current
10 mA
Screen Current
2.8 mA

Other

Conversion Conductance
2100 uS
Mixer

Data set 05

1975 RCA RC30

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Miniature type used as combined oscillator and mixer
9 V
Other;PublishedValue1
Miniature type used as combined oscillator and mixer
0.3 V
Other;PublishedValue2
Miniature type used as combined oscillator and mixer
100 V
Other;PublishedValue3
Miniature type used as combined oscillator and mixer
-200 V
Other;PublishedValue4
Plate Supply Voltage
650 V
MaximumRating;PublishedValue1
Plate Supply Voltage
550 V
MaximumRating;PublishedValue2
Plate Voltage
250 V
MaximumRating;PublishedValue1
Plate Voltage
250 V
MaximumRating;PublishedValue2
Grid-No
2 V
MaximumRating;PublishedValue1
Grid-No
175 V
MaximumRating;PublishedValue2
Cathode Current
14 mA
MaximumRating;PublishedValue1
Cathode Current
14 mA
MaximumRating;PublishedValue2
Plate Dissipation
1.5 W
MaximumRating;PublishedValue1
Plate Dissipation
1.7 W
MaximumRating;PublishedValue2
Grid-No
2 W
MaximumRating;PublishedValue1
Grid-No
0.5 W
MaximumRating;PublishedValue2
For fixed-bias operation
0.5 megohm
MaximumCircuitValue;PublishedValue1
For fixed-bias operation
0.5 megohm
MaximumCircuitValue;PublishedValue2
For cathode-bias operation
0.5 megohm
MaximumCircuitValue;PublishedValue1
For cathode-bias operation
1 megohm
MaximumCircuitValue;PublishedValue2
Maximum Plate Voltage
250 V
Section1
Maximum Plate Dissipation
1.5 W
Section1
Maximum Cathode Current
14 mA
Section1

Characteristic

Plate Voltage
100 V
Characteristic;PublishedValue1
Plate Voltage
170 V
Characteristic;PublishedValue2
Grid-No.l Voltage
-2 V
Characteristic
Plate Resistance (Approx.) —
0.4 megohm
Characteristic
Plate Current
14 mA
Characteristic;PublishedValue1
Plate Current
10 mA
Characteristic;PublishedValue2
Grid-No
2 mA
Characteristic;PublishedValue1
Grid-No
2.8 mA
Characteristic;PublishedValue2
Transconductance
5000 uS
Section1
Amplification Factor
20
Section1

SECTION 2

Pentode

Other

Maximum Plate Voltage
250 V
Section2
Maximum Screen Voltage
175 V
Section2
Maximum Plate Dissipation
1.7 W
Section2
Maximum Screen Dissipation
0.5 W
Section2
Maximum Cathode Current
14 mA
Section2

Characteristic

Plate Resistance
400000 ohm
Section2
Transconductance
6200 uS
Section2