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Power - Triode Single (under 10W) ·Triode

402P

Cossor triode valve documented with construction, technical data, operating recommendations, and application notes; available evidence does not justify a narrower functional category.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
B4
Base pins
-
Nominal heater
40 V / 200 mA

Description

402P: Cossor triode valve. The complete Cossor sheet was read for construction, technical data, operating recommendations, and application notes.

Socket description

European 4-pin base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
B4
Base pins
-
Nominal heater voltage
40 V
Nominal heater current
200 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

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
1330 Ω
Transconductance
0.0075 S
Amplification factor
10
Max plate voltage
200 V
Max plate dissipation
8 W

Published ratings/characteristics promoted from the approved datasheet.

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

1936 Cossor Valve Manual

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristics

  • Heater/filament voltage

    40 V

  • Heater/filament current

    200 mA

Other

  • Maximum anode voltage

    200 V

  • Maximum anode dissipation

    8 W

Data set 02

193X Cossor

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Filament/Heater Current

    200 mA

    Published technical-data value

  • Maximum Anode Voltage

    200 V

    Published technical-data value

Characteristics

  • Mutual Conductance

    7500 µS

    Published technical-data value

  • Amplification Factor

    10

    Published technical-data value