8904

Compact rugged radial-beam tetrode, co-designated 4CX350FJ, for RF power amplification with 350 W plate dissipation and plate ratings to approximately 2.5 kV.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: B8-236
Socket code: -
Base pins: 9
Nominal heater: 26.5 V / 650 mA

Description

Compact rugged radial-beam tetrode; shared 8904/4CX350FJ designation.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: B8-236
Socket code: -
Base pins: 9
Nominal heater voltage: 26.5 V
Nominal heater current: 650 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

B8-236 - 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

Tetrode

X-ray radiationInterelectrode capacitances

Transconductance: 0.022 S
Amplification factor: 17
Max plate voltage: 2500 V
Max screen voltage: 400 V
Max plate dissipation: 350 W
Max screen dissipation: 8 W

Promoted values are taken from printed General Characteristics / Maximum Ratings. Additional published conditions and operating data are preserved in 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

1962 Eimac

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Capacitance

Input Capacitance
22 pF
Output Capacitance
5.9 pF
Feedback Capacitance
0.033 pF

Other

Maximum DC Plate Current
300 mA
ClassAB1
Typical Plate Voltage
2200 V
ClassAB1
Typical Screen Voltage
400 V
ClassAB1
Typical Useful Output Power
250 W
ClassAB1