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Voltage Dual Tetrode ·Tetrode-Tetrode

7G8

Sharp-cutoff double tetrode with common cathode and screen, intended for general amplifier service.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: 8BV
Socket code: LOCTAL8
Base pins: 8
Nominal heater: 7 V / 320 mA

Description

Sharp-cutoff double tetrode with common cathode and screen, intended for amplifier service.

Socket description

Loctal 8-contact base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: 8BV
Socket code: LOCTAL8
Base pins: 8
Nominal heater voltage: 7 V
Nominal heater current: 320 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

8BV - 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

Tetrode

X-ray radiationInterelectrode capacitances

Plate resistance: 225000 Ω
Transconductance: 0.0021 S
Max plate voltage: 300 V
Max screen voltage: 100 V
Max plate dissipation: 1.5 W
Max screen dissipation: 0.1 W
Rectifier max heater-cathode voltage: 0 V

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

Section 2

Tetrode

X-ray radiationInterelectrode capacitances

Plate resistance: 225000 Ω
Transconductance: 0.0021 S
Max plate voltage: 300 V
Max screen voltage: 100 V
Max plate dissipation: 1.5 W
Max screen dissipation: 0.1 W

Second physical tetrode 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

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Capacitance

Input capacitance
3.4 pF
PerSection
Output capacitance
2.6 pF
PerSection
Grid-to-plate capacitance
0.15 pF
PerSection

Other

Plate voltage
250 V
ClassA;PerSection
Screen-grid voltage
100 V
ClassA;PerSection
Grid voltage
-2.5 V
ClassA;PerSection
Plate current
4.5 mA
ClassA;PerSection
Screen-grid current
0.8 mA
ClassA;PerSection

Characteristic

Plate resistance
225000 ohm
ClassA;PerSection
Transconductance
2100 uS
ClassA;PerSection

Data set 02

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Characteristic

Plate Resistance
225000 ohm
PerUnit
Transconductance
2100 uS
PerUnit