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Power - Pentode (NOT beam) ·Pentode

7751

Rugged long-life power pentode for high-current switching, regulated-supply pass service, and high-power push-pull operation.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
Octal / 7AC
Socket code
IO
Base pins
8
Nominal heater
6.3 V / 1.2 A

Description

The Telefunken 7751 is a rugged long-life power pentode for high-current service, including 30 W push-pull Class B operation.

Socket description

International Octal

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
Octal / 7AC
Socket code
IO
Base pins
8
Nominal heater voltage
6.3 V
Nominal heater current
1.2 A
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

Octal / 7AC - 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
5000 Ω
Transconductance
0.014 S
Amplification factor
5.6
Max plate voltage
250 V
Max screen voltage
250 V
Max plate dissipation
10 W
Max screen dissipation
5 W
Max cathode current
200 mA

Beam power pentode; characteristics at 100 V plate/screen.

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

1959 Telefunken

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristics

  • Plate Voltage

    100 V

  • Screen Voltage

    100 V

  • Plate Current

    100 mA

  • Transconductance

    14000 uS

  • Guaranteed Life

    10000 h

    Average of 100 tubes

Other

  • Power Output

    30 W

    ClassB; PushPull; TwoTubes; PlateVoltage=250V; ScreenVoltage=170V

Data set 02

1960 CBS Hytron

Published operating points and test conditions from this source.

SECTION 1

Pentode

Capacitance

  • Input capacitance

    17.5 pF

  • Output capacitance

    9 pF

  • Grid-to-plate capacitance maximum

    1.3 pF

Other

  • Plate supply voltage at zero current

    550 V

  • Screen-grid supply voltage at zero current

    550 V

  • Plate and screen total dissipation

    13 W

Characteristics

  • Plate supply voltage

    100 V

  • Screen-grid voltage

    100 V

  • Control-grid voltage

    -8.2 V

  • Plate current

    100 mA

  • Screen-grid current

    7 mA

  • Internal resistance at zero grid bias

    100 Ohm