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Tube Tinker — Electron Tube Database
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Voltage - Triode (single) ·Triode

4094A

Directly heated triode using a thoriated-tungsten filament, molybdenum anode, and hard-glass bulb, documented with Standard Valves operating and construction data.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
LARGE4BAYONET
Base pins
4
Nominal heater
10 V / 3.25 A

Description

Directly heated triode. This valve is similar to the 4012-A valve but employs a thoriated tungsten filament, molybdenum anode and hard glass bulb. SPECIFICATION. Cathode. Thoriated tungsten filament. Constant voltage type. Base

Socket description

Large 4-contact bayonet base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
LARGE4BAYONET
Base pins
4
Nominal heater voltage
10 V
Nominal heater current
3.25 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
9300 Ω
Transconductance
0.004 S
Amplification factor
37
Max plate voltage
1250 V
Max plate dissipation
85 W
Max cathode current
150 mA

Published ratings and characteristics promoted where directly established by the 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

1946 Standard Telephone and Cables

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristics

  • Mutual conductance

    4000 µS

    Published characteristic; normalized from mA/V

Other

  • Grid-filament capacity

    9 pF

    Published interelectrode capacitance

  • Maximum direct anode current

    150 mA

    Maximum safe operating rating