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

Voltage Pentode or Tetrode (under 100V) ·Diode-Pentode

1AJ5

Directly heated diode and sharp-cutoff pentode combination designed for low-voltage Class-A amplifier service in battery-operated equipment.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
1AJ5
Socket code
-
Base pins
-
Nominal heater
1.25 V / 400 mA

Description

Directly heated combination diode and sharp-cutoff pentode for low-voltage Class-A amplifier service.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
1AJ5
Socket code
-
Base pins
-
Nominal heater voltage
1.25 V
Nominal heater current
400 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

1AJ5 - Terminal pinout

Electrical assignments shared by every tube using this base designation.

No verified pinout is recorded for this base designation.

Section ratings

2 physical sections, each with unique specifications.

Section 1

Diode

X-ray radiationInterelectrode capacitances

No fixed ratings are recorded for this section.

Promoted from the printed condensed-manual maximum/characteristic columns; operating-point values are retained in TUBE_SECTION_PARAMETER. The condensed chart identifies a diode section but gives no separate diode limiting ratings.

Section 2

Pentode

X-ray radiationInterelectrode capacitances
Plate resistance
300000 Ω
Transconductance
0.000425 S
Max plate voltage
90 V
Max screen voltage
90 V

Promoted from the printed condensed-manual maximum/characteristic columns; operating-point values are retained in TUBE_SECTION_PARAMETER.

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

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 2

Pentode

Capacitance

  • Input capacitance

    1.7 pF

    Section2

  • Output capacitance

    2.4 pF

    Section2

  • Grid-to-plate capacitance

    0.1 pF

    Section2

Other

  • Plate voltage

    45 V

    ClassA

  • Screen voltage

    45 V

    ClassA

  • Plate current

    1 mA

    ClassA

  • Screen current

    0.3 mA

    ClassA

Characteristic

  • Plate resistance

    300000 Ω

    ClassA

  • Transconductance

    425 µS

    ClassA