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Power - Triode ·Triode

4033L

Cross-designation and replacement form of the 3B252B power triode for audio and RF service. Its low plate resistance, moderate amplification factor, 25 W plate dissipation, and 600 V rating suit driver, output, and transmitter stages.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
B5
Base pins
5
Nominal heater
6 V / 1.4 A

Description

4033L printed cross-designation/replacement designation for 3B252B. Power triode for audio and radio-frequency service.

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
5
Nominal heater voltage
6 V
Nominal heater current
1.4 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
1670 Ω
Transconductance
0.009 S
Amplification factor
15
Max plate voltage
600 V
Max plate dissipation
25 W

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

1947 Standard Valves

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristics

  • GridToAnodeCapacitance

    8 pF

  • Grid To Cathode Capacitance

    4 pF

  • Anode To Cathode Capacitance

    10 pF

Other

  • MaximumDirectAnodeCurrent

    170 mA

  • MaximumDirectGridCurrent

    30 mA