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Voltage Dual Pentode ·Pentode-Pentode

6GS8

Twin pentode with shared control electrodes designed for combined television sync and automatic-gain-control functions.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
9FG
Socket code
B9A
Base pins
9
Nominal heater
6.3 V / 300 mA

Description

The 6GS8 is a twin pentode with separate plates and third grids but common screen, control grid, and cathode, intended for combined sync and AGC functions 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
9FG
Socket code
B9A
Base pins
9
Nominal heater voltage
6.3 V
Nominal heater current
300 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

9FG - Terminal pinout

Electrical assignments shared by every tube using this base designation.

TerminalSectionConnectionEvidence
PIN1Base Pin—K — Cathode

Original chart label: K; manufacturer verification pending

Unverified

EIA Base Connections, printed page 132, 9FG

PIN2Base Pin—G2 — Screen GridGroup 9FG2

Original chart label: G2; manufacturer verification pending

Unverified

EIA Base Connections, printed page 132, 9FG

PIN2Base Pin—IS — Internal ScreenGroup 9FG2

Original chart label: IS; manufacturer verification pending

Unverified

EIA Base Connections, printed page 132, 9FG

PIN3Base PinBP — Plate (Anode)

Original chart label: 2P; manufacturer verification pending

Unverified

EIA Base Connections, printed page 132, 9FG

PIN4Base Pin—H — Heater

Original chart label: H; manufacturer verification pending

Unverified

EIA Base Connections, printed page 132, 9FG

PIN5Base Pin—H — Heater

Original chart label: H; manufacturer verification pending

Unverified

EIA Base Connections, printed page 132, 9FG

PIN6Base PinBG3 — Suppressor Grid

Original chart label: 2G3; manufacturer verification pending

Unverified

EIA Base Connections, printed page 132, 9FG

PIN7Base Pin—G1 — Control Grid

Original chart label: G1; manufacturer verification pending

Unverified

EIA Base Connections, printed page 132, 9FG

PIN8Base PinAP — Plate (Anode)

Original chart label: 1P; manufacturer verification pending

Unverified

EIA Base Connections, printed page 132, 9FG

PIN9Base PinAG3 — Suppressor Grid

Original chart label: 1G3; manufacturer verification pending

Unverified

EIA Base Connections, printed page 132, 9FG

Section ratings

2 physical sections, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances
Transconductance
0.0012 S
Max plate voltage
300 V
Max screen voltage
150 V
Max plate dissipation
1.1 W
Max screen dissipation
0.75 W
Max cathode current
12 mA

Representative section for two electrically similar physical sections.

Section 2

Pentode

X-ray radiationInterelectrode capacitances
Transconductance
0.0012 S
Max plate voltage
300 V
Max screen voltage
150 V
Max plate dissipation
1.1 W
Max screen dissipation
0.75 W
Max cathode current
12 mA

Second physical pentode 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

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Heater voltage

    6.3 V

  • Heater current

    300 mA

  • Plate voltage

    100100 V

    Typical operating conditions

  • Screen voltage

    150 V

    Typical operating conditions

  • Plate current

    2 mA

    Typical operating conditions

Data set 02

1966 Tung Sol Electronic Tubes 2 of 4

Published operating points and test conditions from this source.

SECTION 1

Pentode

Capacitance

  • Grid 3 to plate capacitance

    2 pF

  • Grid 1 total capacitance

    6 pF

  • Grid 3 total capacitance

    3.6 pF

  • Plate total capacitance

    3 pF

Other

  • Plate voltage

    200 V

    EachSectionSeparately

  • Screen voltage

    67.5 V

    EachSectionSeparately

  • Plate current

    2 mA

    EachSectionSeparately

Characteristics

  • Grid 3 transconductance

    270 µS

    EachSectionSeparately

  • Grid 1 cutoff voltage

    -2 V

    Ib=100uA