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Power - Pentode (NOT beam) ·Pentode

312A

Power pentode designed primarily for Class-C radio-frequency transmitting, amplifier, oscillator, or modulated RF service.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
UX4
Base pins
4
Nominal heater
5 V / 250 mA

Description

Air-cooled transmitting pentode for Class-C RF power amplifier service.

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
4
Nominal heater voltage
5 V
Nominal heater current
250 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
4700 Ω
Transconductance
0.0018 S
Amplification factor
8.5
Max plate voltage
180 V
Max plate dissipation
50 W

Core published characteristics promoted conservatively from the approved manual sheet.

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

193X Cunningham

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristics

  • Heater/filament voltage

    5 V

    Published nominal

  • Heater/filament current

    250 mA

    Published nominal

  • Transconductance

    1800 uS

    Published characteristic

  • Amplification factor

    8.5

    Published characteristic

  • Plate resistance

    4700 Ohm

    Published characteristic

Data set 02

1956 Western Electric Tubes

Published operating points and test conditions from this source.

SECTION 1

Pentode

Application

  • Tube service

    Transmitting tube

Other

  • Typical RF power output

    23 W

    ClassC