Data set 01
2026 Western Electric 400s
Published operating points and test conditions from this source.
SECTION 1
Beam Power
Capacitance
Grid to plate maximum
1.5 pF
Input
8.5 pF
Output
5 pF
Characteristic
Typical zero-signal plate current
41 mA
Power - Beam (NOT sweep) ·BeamPower
429A
Western Electric indirectly heated beam pentode originally designed for telegraph service-board circuits and also suitable for audio-frequency amplification.
Directly heatedCold cathodeCommon cathodeDissimilar
- Sections
- 1
- Base
- -
- Socket code
- -
- Base pins
- 9
- Nominal heater
- 20 V / 140 mA
Description
Western Electric 429A is an indirectly heated beam pentode originally designed for telegraph service-board circuits and also suitable as an audio-frequency amplifier.
General specifications
Tube and section characteristics
Properties common to every published source and operating point.
Heater and base
- Base
- -
- Socket code
- -
- Base pins
- 9
- Nominal heater voltage
- 20 V
- Nominal heater current
- 140 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
Beam Power
X-ray radiationInterelectrode capacitances
- Plate resistance
- 37000 Ω
- Transconductance
- 0.0066 S
- Max plate voltage
- 275 V
- Max screen voltage
- 150 V
- Max plate dissipation
- 12 W
- Max screen dissipation
- 2 W
- Max cathode current
- 75 mA
Promoted from published maximum ratings and typical characteristics.
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.