Skip to main content
Tube Tinker — Electron Tube Database
Alternatives & variationsDownload PDF datasheet

Voltage Pentode - Sharp Cutoff (single) ·Pentode

7L7

Sharp-cutoff pentode designed for RF, IF, wide-band, or high-frequency voltage-amplifier service.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
8V
Socket code
B8G
Base pins
8
Nominal heater
6.3 V / 300 mA

Description

Sharp-cutoff high-transconductance lock-in pentode useful as an IF amplifier or limiter in FM equipment.

Socket description

Loctal 8-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
8V
Socket code
B8G
Base pins
8
Nominal heater voltage
6.3 V
Nominal heater current
300 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

8V - Terminal pinout

Electrical assignments shared by every tube using this base designation.

TerminalSectionConnectionEvidence
PIN1H—H — Heater

EIA source transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 8V

PIN2PAP — Plate (Anode)

EIA source transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 8V

PIN3G2AG2 — Screen Grid

EIA source transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 8V

PIN4G3AG3 — Suppressor Grid

EIA source transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 8V

PIN5ISAIS — Internal Screen

EIA chart transcription; manufacturer verification pending

Unverified

EIA Base Connections, printed page 129, 8V

PIN6G1AG1 — Control Grid

EIA chart transcription; manufacturer verification pending

Unverified

EIA Base Connections, printed page 129, 8V

PIN7KAK — Cathode

EIA chart transcription; manufacturer verification pending

Unverified

EIA Base Connections, printed page 129, 8V

PIN8H—H — Heater

EIA chart transcription; manufacturer verification pending

Unverified

EIA Base Connections, printed page 129, 8V

Section ratings

1 physical section, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances
Plate resistance
1000000 Ω
Transconductance
0.0031 S
Max plate voltage
300 V
Max screen voltage
150 V
Max plate dissipation
3 W
Max screen dissipation
0.7 W
Rectifier max heater-cathode voltage
90 V

Published promoted fields populated by semantic section ownership; 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

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Pentode

Capacitance

  • Input capacitance

    8 pF

  • Output capacitance

    6.5 pF

  • Grid-to-plate capacitance

    0.01 pF

Other

  • Plate voltage

    250 V

    ClassA

  • Screen-grid voltage

    100 V

    ClassA

  • Grid voltage

    -1.5 V

    ClassA

  • Plate current

    4.5 mA

    ClassA

  • Screen-grid current

    1.5 mA

    ClassA

Characteristic

  • Plate resistance

    1000000 ohm

    ClassA

  • Transconductance

    3100 uS

    ClassA

Data set 02

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

  • Transconductance

    3100 uS

    PlateVoltage=250V