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Voltage - Triode (single) ·Triode

C408

Triode designed for valve voltmeters and measuring instruments, with published operating and characteristic values for precision electronic measurement.

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

Description

C408 is listed in the supplied valve table as a triode for valve voltmeters and measuring instruments. Published operating and characteristic values were transcribed from its target row.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
-
Base pins
-
Nominal heater voltage
4 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

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
3000 Ω
Transconductance
0.0027 S
Amplification factor
8

Published operating point, characteristic values and capacitance column reviewed.

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

    150 V

    Published table operating point

  • Plate current

    14 mA

    Published table operating point

  • Control-grid bias

    7 V

    Published table operating point

Characteristic

  • Transconductance

    2700000 µS

    Published table characteristic

  • Amplification factor

    8

    Published table characteristic

  • Plate resistance

    3000 ohm

    Published table characteristic

  • Heater/filament voltage

    4 V

    Published heater/filament rating

  • Heater/filament current

    250 mA

    Published heater/filament rating