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Voltage - Triode (single) ·Triode

E438

Philips triode for general amplifier service; available source material does not establish a narrower functional application confidently.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
B5
Base pins
-
Nominal heater
4 V / 1 A

Description

E438 is a Triode device in the supplied Philips literature. Philips indirectly heated triode with low-current operating points.

Socket description

European 5-pin base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
B5
Base pins
-
Nominal heater voltage
4 V
Nominal heater current
1 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
120000 Ω
Transconductance
0.0015 S
Amplification factor
38
Max plate dissipation
3 W

Philips indirectly heated triode with low-current operating points.

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

1938 Philips Miniwatt Vacuum Tube Catalog

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Plate voltage

    200 V

    ClassA

  • Plate current

    0.3 mA

    ClassA; OperatingPoint1

  • Grid bias

    -2.5 V

    ClassA; OperatingPoint1

  • Plate current

    0.1 mA

    ClassA; OperatingPoint2

  • Grid bias

    -2.5 V

    ClassA; OperatingPoint2

  • Maximum anode dissipation

    3 W

Characteristic

  • Transconductance

    1.5 mA/V

    ClassA

  • Amplification factor

    38

    ClassA

  • Internal resistance

    120000 ohm

    ClassA; OperatingPoint1

  • Internal resistance

    400000 ohm

    ClassA; OperatingPoint2

Data set 02

1999 Philips E-Z

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Normal plate current

    0.3 mA

    Ra=0.3MOhm

  • External plate resistance

    0.3 MΩ

    Detector