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

Power - Triode ·Triode

2A3H

Heater-cathode triode power amplifier for audio output service, using a 2.5 V heater and substantial Class-A power capability.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
UX4
Base pins
-
Nominal heater
2.5 V / 2.5 A

Description

2A3H is described in the supplied Raytheon datasheet as a heater-cathode triode power amplifier. The published heater/filament rating is 2.5 V at 2.5 A.

Socket description

Medium-shell UX 4-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
UX4
Base pins
-
Nominal heater voltage
2.5 V
Nominal heater current
2.5 A
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

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
800 Ω
Transconductance
0.00525 S
Amplification factor
4.2
Max plate voltage
300 V

Published ratings, characteristics, operating conditions and capacitances reviewed.

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

1937 Raytheon Radio Receiving Tubes

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Maximum plate voltage

    300 V

    Published datasheet rating

  • Plate voltage

    250 V

    ClassA

  • Control-grid bias

    45 V

    ClassA

  • Plate current

    60 mA

    ClassA

  • Load resistance

    2500 ohm

    ClassA

  • Power output

    3.5 W

    ClassA

  • Push-pull plate voltage

    300 V

    ClassAB PushPull TwoTubes

  • Push-pull fixed-bias grid voltage

    62 V

    ClassAB PushPull TwoTubes

  • Push-pull no-signal plate current per tube

    40 mA

    ClassAB PushPull TwoTubes

  • Push-pull load resistance fixed bias

    3000 ohm

    ClassAB PushPull TwoTubes

  • Push-pull power output fixed bias

    15 W

    ClassAB PushPull TwoTubes

  • Push-pull load resistance self bias

    5000 ohm

    ClassAB PushPull TwoTubes

  • Push-pull power output self bias

    10 W

    ClassAB PushPull TwoTubes

Characteristic

  • Plate resistance

    800 ohm

    Published datasheet characteristic

  • Transconductance

    5250 µS

    Published datasheet characteristic

  • Amplification factor

    4.2

    Published datasheet characteristic

  • Heater/filament voltage

    2.5 V

    Published heater/filament rating

  • Heater/filament current

    2.5 A

    Published heater/filament rating