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Power - Beam (NOT sweep) ·BeamPower

7581

High-performance beam-power pentode designed primarily for demanding audio-frequency power-amplifier output stages.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
IO
Base pins
8
Nominal heater
6.3 V / 900 mA

Description

The 7581 is a beam-power pentode intended primarily for audio-frequency power amplification and designed as a high-performance replacement in demanding output stages.

Socket description

International Octal

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

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

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

Beam Power

X-ray radiationInterelectrode capacitances
Plate resistance
22500 Ω
Transconductance
0.006 S
Max plate voltage
500 V
Max screen voltage
400 V
Max plate dissipation
30 W
Max screen dissipation
5 W

Published ratings and characteristics mapped semantically; 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

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Beam Power

Characteristic

  • TriodeConnectionAmplificationFactor

    8

    TriodeConnection

  • TriodeConnectionPlateResistance

    1700 ohm

    TriodeConnection

  • TriodeConnectionTransconductance

    4700 uS

    TriodeConnection

Data set 02

1966 Tung Sol Electronic Tubes 4 of 4

Published operating points and test conditions from this source.

SECTION 1

Beam Power

Characteristic

  • Voltage Operation

    6.3 VOLTS

    PublishedTable

  • Heater Pgsitive With Respect To Cathode

    200 VOLTS

    PublishedTable

  • Heater

    200 voLT

    PublishedTable

  • Plate

    45 VOLTS

    PublishedTable

  • Screen

    45 VOLTS

    PublishedTable

  • Plate

    3 WATTS

    PublishedTable

  • Screen

    5 WATTS

    PublishedTable

  • With Fixed Bias

    1 MEGOHMS

    PublishedTable

  • With Cathode

    5 MEGOHMS

    PublishedTable

  • Plate

    25 VOLTS

    PublishedTable

  • Screen

    25 VOLTS

    PublishedTable

  • Grid #I Voltage

    -14 VOLTS

    PublishedTable

  • Peak Af Grid #1 Voltage

    1 VOLTS

    PublishedTable

  • Plate Resistance, Approx

    22500 OHMS

    PublishedTable

  • Plate Current

    72 MA

    PublishedTable

  • Screen

    5 MA

    PublishedTable

  • Grid #1 Voltage

    -2 VOLTS

    PublishedTable

  • Peak

    1 VOLTS

    PublishedTable

  • Plate

    1 OHMS

    PublishedTable

  • Zero-Signal Plate Current

    4 MA

    PublishedTable

  • Plate

    350 VOLTS

    PublishedTable

Other

  • Maximum- Signal Plate Current

    44 MA

    PublishedTable