3CX400A7

Compact ceramic/metal power triode designed principally for communications and commercial RF amplification in Class A, B, or C service. It also supports pulse-modulator operation and full-rating frequencies reaching approximately 500 MHz.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: E11-81
Socket code: E11
Base pins: 11
Nominal heater: 6.3 V / 3 A

Description

The SvetlanaTM 3CX400A7/8874 is a high performance ceramic/metal power triode designed for use in communications, paging and commercial service. The principal use is as an RF amplifier, in Class A, B or C service. The Svetlana 3CX400A7/8874 may also be operated as a pulse modula- tor with an increase in maximum plate voltage up to 3500 volts. Maximum plate current is 6 amps at a pulse duration of 100 microseconds. The Svetlana 3CX400A7/8874 is a direct replacement for the model 3CX400A7/8874 manufactured in the United States. Characteristics Svetlana Outline drawing Electrical B Cathode: Oxide-coated unipotential J Heater voltage (AC or DC) 6.3 ± 0.3 V K Heater current @ 6.3V 3.0 A Transconductance (average) 29,000 µmhos Maximum frequency at full ratings 500 MHz Anode A Interelectrode capacitances, with cathode grounded: Input 20.5 pF C Output 0.03 pF Grid (Contact F Outer Cylindrical Grid-Plate 6.0 pF Surface Only) G Interelectrode capacitances, with grid grounded: Input 20.5 pF Output 6.0 pF M Plate-Cathode .03 pF

Socket description

Large-wafer Elevenar 11-pin with ring

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: E11-81
Socket code: E11
Base pins: 11
Nominal heater voltage: 6.3 V
Nominal heater current: 3 A
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

E11-81 - 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

Max plate voltage: 2200 V
Max plate dissipation: 400 W
Max grid dissipation: 48 W
Max cathode current: 350 mA

Promoted maximum ratings and characteristics from source; additional published values retained as 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

199X Svetlana

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristics

Heater voltage (AC or DC) 6.3 ±
0.3 V
service. The principal use is as an RF amplifier, in Class A, B or C
Heater current @
6.3 V
service. The principal use is as an RF amplifier, in Class A, B or C
Maximum frequency at full ratings
500 MHz
service. The principal use is as an RF amplifier, in Class A, B or C
Input
20.5 pF
service. The principal use is as an RF amplifier, in Class A, B or C
Output
0.03 pF
service. The principal use is as an RF amplifier, in Class A, B or C
Grid-Plate
6 pF
service. The principal use is as an RF amplifier, in Class A, B or C
Input
20.5 pF
service. The principal use is as an RF amplifier, in Class A, B or C
Output
6 pF
service. The principal use is as an RF amplifier, in Class A, B or C

Other

Maximum-signal DC plate current
350 mA
Maximum ratings Dimensional Data
Plate Dissipation
400 W
Maximum ratings Dimensional Data
Grid Dissipation
5 W
Maximum ratings Dimensional Data
Peak RF grid-cathode voltage 67 50
67 V
Typical Operation, Class AB2 Cathode Driven
Two tone plate current 312 245
300 mA
Typical Operation, Class AB2 Cathode Driven
Zero signal plate current 22 10
22 mA
Typical Operation, Class AB2 Cathode Driven
Two tone grid current 12 10
39 mA
Typical Operation, Class AB2 Cathode Driven
Peak RF drivng power 26 18
27 W
Typical Operation, Class AB2 Cathode Driven
Power output (approx.) 587 526
505 W
Typical Operation, Class AB2 Cathode Driven