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Tube Tinker — Electron Tube Database
Alternatives & variationsDownload PDF datasheet

Power - Pentode (NOT beam) ·Pentode

42E

Brimar companion designation to type 42, sharing its published power-pentode characteristics. Intended for receiver audio power-output service rather than small-signal amplification.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
IO
Base pins
8
Nominal heater
6.3 V / 700 mA

Description

Explicit 42E companion designation on the Brimar 42/42E power-pentode sheet, sharing the same published characteristics.

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
700 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

Pentode

X-ray radiationInterelectrode capacitances
Plate resistance
80000 Ω
Transconductance
0.0025 S

Power pentode.

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

1948 Brimar Radio Valve Manual

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Plate Voltage

    250 V

  • Plate Current

    34 mA

  • Screen Voltage

    250 V

  • Screen Current

    6.5 mA

  • Control Grid Voltage

    -16.5 V

  • Optimum Load

    7000 ohm

  • Power Output

    3.2 W

  • Harmonic Distortion

    8 %

Characteristic

  • Plate Resistance

    80000 ohm

  • Transconductance

    2500 µS