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

Power - Tetrode (NOT beam) (over 1000V 100W) ·Tetrode

PL4D21A

Radiation-cooled 175-watt power tetrode interchangeable with the 4D21/4-125A transmitting family for RF power service.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
GIANT5
Base pins
5
Nominal heater
-

Description

The Penta PL4D21A is a 175 w radiation-cooled power tetrode interchangeable with the 4d21/4-125a family.

Socket description

Giant 5-contact base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
GIANT5
Base pins
5
Nominal heater voltage
-
Nominal heater current
-
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

Tetrode

X-ray radiationInterelectrode capacitances
Transconductance
0.00305 S
Max plate voltage
4000 V
Max screen voltage
600 V
Max plate dissipation
175 W
Max grid dissipation
5 W

Highest reliable published rating promoted; additional values and operating/application details retained as 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

1965 Penta Labs Power Tubes

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Characteristic

  • Transconductance

    3050 uS

Other

  • Maximum plate voltage

    4000 V

  • Maximum screen voltage

    600 V

  • Maximum plate dissipation

    175 W

  • Maximum control-grid dissipation

    5 W

  • Source language

    English

Application

  • Primary application

    175 W radiation-cooled power tetrode interchangeable with the 4D21/4-125A family.

Construction

  • Cooling

    Radiation/convection or source-specific

  • Electrode structure

    Tetrode