Skip to main content
Tube Tinker — Electron Tube Database
Alternatives & variationsDownload PDF datasheet

Power - TV Horizontal Output (sweep) ·Pentode

PL81A

Line-output pentode designed for horizontal-deflection service in portable television receivers.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
B9D
Socket code
B9D
Base pins
9
Nominal heater
21.5 V / 300 mA

Description

Line-output pentode for portable television receivers.

Socket description

Magnoval 9-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
B9D
Socket code
B9D
Base pins
9
Nominal heater voltage
21.5 V
Nominal heater current
300 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

B9D - 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
11500 Ω
Transconductance
0.006 S
Amplification factor
4.9
Max plate voltage
250 V
Max screen voltage
250 V
Max plate dissipation
7.5 W
Max cathode current
180 mA

Line-output pentode; dissipation ratings are chart-defined in the source and pulse ratings retained as 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

1963 Mullard

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristics

  • Characteristic plate voltage

    170 V

  • Characteristic screen voltage

    170 V

  • Characteristic grid voltage

    -24.5 V

  • Plate current

    45 mA

  • Screen current

    2.2 mA

Capacitance

  • Input capacitance

    14 pF

  • Output capacitance

    6 pF

  • Plate-grid capacitance maximum

    0.8 pF

  • Grid-heater capacitance maximum

    0.2 pF

  • Plate-cathode capacitance maximum

    0.1 pF

Other

  • Peak plate voltage maximum

    7000 V

    Pulse

  • Flyback cutoff grid voltage minimum

    -120 V

    Pulse

Data set 02

1967 Mullard Receiving and Amplifying Valves

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

  • Plate voltage

    170 V

  • Screen-grid voltage

    170 V

  • Grid voltage

    -24.5 V

  • Plate current

    45 mA

  • Screen-grid current

    2.2 mA

  • Transconductance

    6000 uS

  • Plate resistance

    11.5 kOhm

Capacitance

  • Input capacitance

    14 pF

  • Output capacitance

    6 pF

  • Plate-grid capacitance

    0.8 pF

  • Grid-heater capacitance

    0.2 pF

  • Plate-cathode capacitance

    0.1 pF

Other

  • Plate supply voltage

    650 V

    HorizontalDeflection

  • Peak plate voltage

    7 kV

    HorizontalDeflection

  • Screen-grid supply voltage

    550 V

    HorizontalDeflection

  • Peak grid voltage

    1 kV

    HorizontalDeflection

Data set 03

1973 Mazda Valves Binder 2

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristics

  • Heater voltage

    21.5 V

    Published nominal value

  • Heater current

    300 mA

    Published nominal value

Other

  • Maximum plate dissipation

    7.5 W

    Published maximum rating

  • Maximum positive peak anode voltage

    7 kV

    Pulse duration <=22% cycle, max 18 us