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Voltage Pentode - Sharp Cutoff (single) ·Pentode

414A

Western Electric miniature pentode for professional small-signal amplifier service in communications and related electronic equipment.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
-
Base pins
7
Nominal heater
6.3 V / 150 mA

Description

Miniature pentode with an indirectly heated cathode.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
-
Base pins
7
Nominal heater voltage
6.3 V
Nominal heater current
150 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
350000 Ω
Transconductance
0.00275 S
Max plate voltage
100 V
Max screen voltage
140 V
Max plate dissipation
1.7 W
Max screen dissipation
0.5 W

Promoted fields mapped from printed maximum-rating and characteristic headings; additional published values preserved in parameter rows.

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

2026 Western Electric 400s

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Screen-Grid Dissipation

    0.5 watt

    Screen-Grid Dissipation 0.5 watt

Characteristic

  • Transconductance

    2750 micromhos

    Transconductance 2750 micromhos

  • brid Voltage (approximate) for ID Microamperes Plate Current

    -9.5 Microamperes

    brid Voltage (approximate) for ID Microamperes Plate Current -9.5 volts