4CX25-000C Datasheet, PDF (1/8 Pages) Communications & Power Industries, Inc. – Cathode driven RF amplifier

The EIMAC 4CX25,000C is a ceramic/metal power
tetrode intended for use as a VHF power amplifier.
It features a type of internal mechanical structure
which results in high rf operating efficiency. Low
rf losses in this structure permit operation at full
ratings to 110 MHz.
The 4CX25,000C is recommended for use in In-
Band-On-Channel (IBOC) FM broadcast service
with combined digital and analog components.
The anode is rated for 25 kilowatts of dissipation
with forced-air cooling and incorporates a com-
pact highly efficient cooler of new design.
RADIAL BEAM POWER
TETRODE 4CX25,000C
Characteristics¹
ELECTRICAL
Filament: Thoriated Tungsten Mesh
Voltage
10.0± 0.5 V
Current at 10.0 Volts
140 A
Amplification Factor, Average, Grid to Screen 6.7
Direct Interelectrode Capacitances (grounded cathode)²
Cin
195 pF
Cout
22.7 pF
Cgp
0.6 pF
Direct Interelectrode Capacitances (grounded grid and screen)²
Cin
87.4 pF
Cout
23.1 pF
Cpk
0.08 pF
Maximum Frequency for Full Ratings (CW) 110 MHz
MECHANICAL:
Maximum Overall Dimensions:
Length
Diameter
Net Weight
Operting Postition

Maximum Operating Temperature:
Ceramic/Metal Seals
Anode Core
Cooling
Base
Recommended Socket for VHF
Recommended Socket for dc to HF
9.84 in; 24.99 mm
8.9 in; 22.6 mm
26.5 lbs. 58.3 kg
Vertical, Base Up or
Down
250° C
250° C
Forced Air
Special, Coaxial
Eimac SK-360
Eimac SK-320
Class of
Operation
B
1 _{Characteristics and operating values are based upon performance tests.} 2 _{In shielded fixture.}
Type of Service
Maximum Ratings
Plate Plate
Voltage Current
(Volts) (Amps)
Plate
Voltage
(Volts)
Typical Operation
Screen Plate Drive Output
Voltage CurrentPower Power
(Volts) (Amps) (Watts) (kiloWatts)
Cathode driven RF amplifier
12,500
5.0
11,500
900
4.1
1025
36.1
The values listed above represent specified limits for the product and are subject to change. The data should be used for basic
information only. Formal, controlled specifications may be obtained from CPI for use in equipment design.
For information on this and other CPI products, visit our website at: www.cpii.com,
or contact: CPI MPP, Eimac Operation, 607 Hansen Way, Palo Alto, CA 94303
telephone: [phone]. fax: [phone] | email: [e-mail]
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