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Voltage Triode Pentode ·Pentode-Triode

7731

High-reliability medium-mu triode plus sharp-cutoff pentode replacement for 6U8.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: E9-1 / 9AE
Socket code: B9A
Base pins: 9
Nominal heater: 6.3 V / 450 mA

Description

Medium-mu triode plus sharp-cutoff pentode, high-reliability replacement for 6U8.

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: E9-1 / 9AE
Socket code: B9A
Base pins: 9
Nominal heater voltage: 6.3 V
Nominal heater current: 450 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

E9-1 / 9AE - 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

Triode

X-ray radiationInterelectrode capacitances

Plate resistance: 5000 Ω
Transconductance: 0.0085 S
Amplification factor: 40
Max plate voltage: 330 V
Max plate dissipation: 3 W

Triode section.

Section 2

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 400000 Ω
Transconductance: 0.0052 S
Max plate voltage: 330 V
Max screen voltage: 330 V
Max plate dissipation: 3 W
Max screen dissipation: 0.6 W

Pentode section; screen operating point in parameters.

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

1960 CBS Hytron

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Plate voltage
150 V
Section1;Triode
Cathode bias resistor
56 Ohm
Section1;Triode

Characteristics

Plate current
18 mA
Section1;Triode

SECTION 2

Pentode

Other

Plate voltage
250 V
Section2;Pentode
Screen-grid voltage
110 V
Section2;Pentode
Cathode bias resistor
68 Ohm
Section2;Pentode

Characteristics

Plate current
10 mA
Section2;Pentode
Screen-grid current
3.5 mA
Section2;Pentode