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Voltage Pentode - Sharp Cutoff (single) ·Pentode

7W7

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

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
8BJ
Socket code
B8G
Base pins
8
Nominal heater
6.3 V / 450 mA

Description

Sharp-cutoff high-transconductance pentode voltage amplifier for high-gain narrow-band service.

Socket description

Loctal 8-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

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

8BJ - Terminal pinout

Electrical assignments shared by every tube using this base designation.

No verified pinout is recorded for this base designation.

Section ratings

1 physical section, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances
Plate resistance
300000 Ω
Transconductance
0.0065 S
Max plate voltage
300 V
Max screen voltage
150 V
Max plate dissipation
4 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

Other

  • Plate voltage

    300 V

    ClassA;CathodeBias

  • Screen-grid voltage

    150 V

    ClassA;CathodeBias

  • Cathode resistor

    160 ohm

    ClassA;CathodeBias

  • Plate current

    10 mA

    ClassA;CathodeBias

  • Screen-grid current

    3.9 mA

    ClassA;CathodeBias

Characteristic

  • Plate resistance

    300000 ohm

    ClassA

  • Transconductance

    5800 uS

    ClassA

Data set 02

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

  • Transconductance

    6500 uS

    Typical