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

Power - Pentode (NOT beam) ·Pentode

EL821

High-transconductance video-output power pentode designed particularly for high-definition television equipment. Its substantial mutual conductance and output capability support wideband video load drive.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
B9A
Socket code
B9A
Base pins
9
Nominal heater
6.3 V / 750 mA

Description

VIDEO OUTPUT PENTODE Video output pentode having a high mutual conductance, particularly suitable for use in high definition television EL82 I equipment.

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
B9A
Socket code
B9A
Base pins
9
Nominal heater voltage
6.3 V
Nominal heater current
750 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

B9A - 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
50000 Ω
Transconductance
0.011 S
Amplification factor
26
Max plate voltage
275 V
Max screen voltage
275 V
Max plate dissipation
12 W
Max screen dissipation
2.5 W
Max cathode current
60 mA

Published electrical characteristics and ratings promoted from supplied datasheet.

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

Capacitance

  • Input capacitance

    14 pF

  • Output capacitance

    5 pF

Characteristic

  • Anode current

    40 mA

    Va=250V; Vg2=250V

  • Screen current

    6 mA

    Va=250V; Vg2=250V

Data set 02

1967 Mullard Receiving Tubes for Maintenance

Published operating points and test conditions from this source.

SECTION 1

Pentode

Capacitance

  • Va(b) ma x

    550 ma

    CAPACITANCES (measured w ithout an external sh ield)

  • Vg

    550 ma

    CAPACITANCES (measured w ithout an external sh ield)

  • Vg

    275 ma

    CAPACITANCES (measured w ithout an external sh ield)

  • Rg l - k ma x. (cathode bias)

    220 ma

    CAPACITANCES (measured w ithout an external sh ield)