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Power - Triode Single (under 10W) ·Triode

C405

Directly heated Philips power triode for audio output-stage service, with approximately 5 W maximum anode dissipation and low internal resistance.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
A32
Socket code
-
Base pins
-
Nominal heater
4 V / 300 mA

Description

Philips C405 is a directly heated power triode intended for output-stage service, with a 4 V, approximately 0.30 A filament, 5 W anode dissipation and low internal resistance.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
A32
Socket code
-
Base pins
-
Nominal heater voltage
4 V
Nominal heater current
300 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

A32 - 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
2600 Ω
Transconductance
0.0019 S
Amplification factor
5
Max plate voltage
250 V
Max plate dissipation
5 W
Max cathode current
25 mA

Published ratings and characteristics promoted where semantically applicable; additional published values retained as section parameters.

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

1999 Philips 0-D

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Typical anode voltage

    250 V

    Published datasheet value

  • Normal anode current

    20 mA

    Published datasheet value

  • Grid bias

    -2 V

    Published datasheet value

  • Output load resistance

    5200 Ω

    Published datasheet value

Characteristics

  • Maximum transconductance

    - to 2 mA/V

    Published datasheet value

  • Normal transconductance

    1.9 mA/V

    Published datasheet value

  • Internal resistance

    2600 Ω

    Published datasheet value

  • Amplification factor

    5

    Published datasheet value

  • Maximum grid-circuit resistance

    - to 1.5 MΩ

    Published datasheet value

  • Interelectrode capacitance 1

    4.8 pF

    Published datasheet value

  • Interelectrode capacitance 2

    8.4 pF

    Published datasheet value

  • Interelectrode capacitance 3

    5.3 pF

    Published datasheet value