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Voltage Dual Pentode ·Pentode-Pentode

3GS8

Sharp-cutoff twin pentode designed as combined television sync separator, sync clipper, and automatic-gain-control amplifier.

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

Description

Sharp-cutoff twin pentode used as combined sync separator, sync clipper, and AGC amplifier in television 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
-
Socket code
B9A
Base pins
9
Nominal heater voltage
3.15 V
Nominal heater current
600 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

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

Pentode

X-ray radiationInterelectrode capacitances
Transconductance
0.0015 S
Max plate voltage
300 V
Max screen voltage
150 V
Max plate dissipation
1.1 W
Max screen dissipation
1 W
Max cathode current
12 mA
Rectifier max heater-cathode voltage
200 V
Rectifier warm-up time
11 s

Published promoted fields populated by semantic headings; identical repeated sections compressed.

Section 2

Pentode

X-ray radiationInterelectrode capacitances
Transconductance
0.0015 S
Max plate voltage
300 V
Max screen voltage
150 V
Max plate dissipation
1.1 W
Max screen dissipation
1 W
Max cathode current
12 mA

Second physical pentode section; 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

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

  • Grid3 Transconductance

    270 uS

    EachSection

  • Grid4Transconductance

    1200 uS

    EachSection

Data set 02

1966 Tung Sol Electronic Tubes 1 of 4

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Plate voltage

    100 V

    SyncAGC;EachSection

  • Screen voltage

    67.5 V

    SyncAGC;EachSection

  • Grid-3 voltage

    -10 V

    SyncSeparatorSection

  • Grid-3 voltage

    0 V

    AGCSection

  • Plate current

    2 mA

    SyncAGC;EachSection

  • Screen current

    6 mA

    Condition1

  • Screen current

    3.6 mA

    Condition2

  • Cathode current

    6.1 mA

    Condition1

  • Cathode current

    7.7 mA

    Condition2

  • Application

    Combined sync separator-clipper and AGC tube

    Section1

Data set 03

1971 RCA HB3 Binder 4 of 7

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Heater Current

    560 mA to 640 mA

    Published nominal ± tolerance

  • Heater Voltage

    3.15 V

    At heater current 0.6 A

  • Warm-Up Time

    11 s

    Average

  • Plate Voltage

    300 V

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

  • Screen Voltage

    150 V

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

  • Cathode Current

    12 mA

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

  • Plate Dissipation

    1.1 W

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

  • Screen Input

    0.75 W

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

  • Plate Voltage

    100 V

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

  • Screen Voltage

    67.5 V

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

  • Plate Current

    2.2 mA

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

Characteristics

  • Grid No.1 Transconductance

    1500 µS

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

  • Grid No.3 Transconductance

    180 µS

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

Data set 04

1975 RCA RC30

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Tube Voltage Drop for plate current of

    140 mA

    Published in approved 4GS8 target entry; Section1

  • Tube Voltage Drop for plate current of 140 mA

    12 V

    Published in approved 4GS8 target entry; Section1

  • Heater Voltage (ac/dc) 3.15 4.2

    6.3 V

    Published in approved 4GS8 target entry; Section1

  • Heater Current 0.6 0.45

    300 mA

    Published in approved 4GS8 target entry; Section1

  • Heater Warm-up Time (Average) 11

    11 seconds

    Published in approved 4GS8 target entry; Section1

  • Plate Voltage (Each Unit)

    300 V

    Published in approved 4GS8 target entry; Section1

  • Peak positive value

    50 V

    Published in approved 4GS8 target entry; Section1

  • DC negative value

    50 V

    Published in approved 4GS8 target entry; Section1

  • DC positive value

    3 V

    Published in approved 4GS8 target entry; Section1

  • Grid-No.2 (Screen-Grid) Voltage

    150 V

    Published in approved 4GS8 target entry; Section1

  • Grid-No.l (Control-Grid) Voltage, Negative bias value

    50 V

    Published in approved 4GS8 target entry; Section1

  • Cathode Current

    12 mA

    Published in approved 4GS8 target entry; Section1

  • Plate Dissipation (Each Unit)

    1.1 W

    Published in approved 4GS8 target entry; Section1

  • Grid-No.2 Input

    0.75 W

    Published in approved 4GS8 target entry; Section1

  • Plate Voltage (Each Unit) 100

    100 V

    Published in approved 4GS8 target entry; Section1

  • Plate Current

    2.2 mA

    Published in approved 4GS8 target entry; Section1

  • 100 aA —

    -4.6 V

    Published in approved 4GS8 target entry; Section1

  • 100 M —

    -2.3 V

    Published in approved 4GS8 target entry; Section1

  • Grid-No.3-Circuit Resistance (Each Unit)

    0.5 MΩ

    Published in approved 4GS8 target entry; Section1

  • Grid-No.l-Circuit Resistance

    0.5 MΩ

    Published in approved 4GS8 target entry; Section1

  • ORID-No

    3 V

    Published in approved 4GS8 target entry; Section1

  • GRID-No

    2 V

    Published in approved 4GS8 target entry; Section1

  • Heater Voltage (ac/dc) 6.3

    12.6 V

    Published in approved 4GS8 target entry; Section1

  • Heater Current 0.9

    450 mA

    Published in approved 4GS8 target entry; Section1

  • Heater Warm-up Time

    11 seconds

    Published in approved 4GS8 target entry; Section1

  • DC Plate Voltage

    300 V

    Published in approved 4GS8 target entry; Section1

  • Positive-bias value

    25 V

    Published in approved 4GS8 target entry; Section1

  • Negative-bias value

    100 V

    Published in approved 4GS8 target entry; Section1

Capacitance

  • Grid No. 3 to Plate (Each Unit)

    1.9 pF

    Published in approved 4GS8 target entry; Section1

  • Grid No.l to All Other Electrodes

    6 pF

    Published in approved 4GS8 target entry; Section1

  • Grid No.3 to All Other Electrodes (Each Unit)

    3.6 pF

    Published in approved 4GS8 target entry; Section1

  • Plate to All Other Electrodes (Each Unit)

    3 pF

    Published in approved 4GS8 target entry; Section1

  • Grid No.l to Plate

    0.1 pF

    Published in approved 4GS8 target entry; Section1

  • Internal Shield

    7 pF

    Published in approved 4GS8 target entry; Section1

  • Grid No.3 to All Other Electrodes

    8.5 pF

    Published in approved 4GS8 target entry; Section1

  • Grid No.l to Grid No.3

    0.08 pF

    Published in approved 4GS8 target entry; Section1

Characteristic

  • Grid-No-3 Voltage (Each Unit) —10

    0 V

    Published in approved 4GS8 target entry; Section1

  • Grid-No.2 Voltage 67.6

    67.5 V

    Published in approved 4GS8 target entry; Section1

  • Plate Current (Each Unit)

    2.2 mA

    Published in approved 4GS8 target entry; Section1

  • Grid-No.2 Current 6.5

    3.3 mA

    Published in approved 4GS8 target entry; Section1

  • Cathode Current 6.6

    7.8 mA

    Published in approved 4GS8 target entry; Section1

  • Plate Voltage 100

    100 V

    Published in approved 4GS8 target entry; Section1

  • Grid-No.3 Voltage 0

    0 V

    Published in approved 4GS8 target entry; Section1

  • Grid-No.2 Voltage 67.5

    67.5 V

    Published in approved 4GS8 target entry; Section1

  • Grid-No.3 Transconductance

    180 µS

    Published in approved 4GS8 target entry; Section1