4CX25000A

High-power ceramic/metal transmitting tetrode designed for RF power amplification, linear amplification, oscillation, modulation, broadcast, or related high-power service.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: -
Socket code: -
Base pins: -
Nominal heater: 9.5 V / 150 A

Description

Ceramic/metal forced-air-cooled power tetrode intended for VHF-TV linear-amplifier service, with full ratings through 230 MHz and 25 kW anode dissipation.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: -
Base pins: -
Nominal heater voltage: 9.5 V
Nominal heater current: 150 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

Tetrode

X-ray radiationInterelectrode capacitances

Amplification factor: 6.7
Max plate voltage: 10000 V
Max screen voltage: 2000 V
Max plate dissipation: 25000 W
Max screen dissipation: 300 W
Max grid dissipation: 180 W

Published absolute maximum ratings promoted from the applicable service tables; pulse-service maxima are used only where explicitly noted in the tube note.

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

Other

Heater/Filament Voltage
9.5 V
Heater/Filament Current
150 A
At 9.5 V nominal
Frequency for Maximum Ratings
230 MHz
Maximum Plate Voltage
10000 V
Highest published applicable absolute maximum
Maximum Screen Voltage
2000 V
Highest published applicable absolute maximum
Maximum Plate Dissipation
25000 W
Maximum Screen Dissipation
300 W
Maximum Grid Dissipation
180 W
Maximum DC Plate Current
8 A
Plate Voltage
7800 V
TelevisionLinearAmplifier;Channels7-13;CathodeDriven
Screen Voltage
1400 V
TelevisionLinearAmplifier;Channels7-13;CathodeDriven
Plate Output Power
34700 W
TelevisionLinearAmplifier;PeakSync

Characteristic

Grid-Screen Amplification Factor
6.7

Capacitance

Input Capacitance
171 pF
GroundedCathode
Output Capacitance
18.4 pF
GroundedCathode
Feedback Capacitance
0.57 pF
GroundedCathode
Input Capacitance
79 pF
GroundedGrids
Output Capacitance
19 pF
GroundedGrids
Feedback Capacitance
0.06 pF
GroundedGrids