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Power - Tetrode (NOT beam) ·Diode-Tetrode

4CS100L

Eimac metal-ceramic quick-heating power tetrode with a built-in control diode for portable and mobile transmitters. The integrated diode permits rapid operation with minimal auxiliary circuitry.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
-
Socket code
-
Base pins
-
Nominal heater
2.1 V / 7.625 A

Description

The Eimac 4CS100L is a metal-ceramic quick-heating power tetrode for portable and mobile transmitters, with a built-in control diode that permits very rapid operation using minimal additional circuitry.

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
2.1 V
Nominal heater current
7.625 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

2 physical sections, each with unique specifications.

Section 1

Tetrode

X-ray radiationInterelectrode capacitances
Transconductance
0.02 S
Amplification factor
11.5
Max plate voltage
2000 V
Max screen voltage
400 V
Max plate dissipation
100 W
Max screen dissipation
8 W
Max grid dissipation
0.5 W
Max cathode current
300 mA

Main power-tetrode section; amplification factor is published as a 10–13 range.

Section 2

Diode

X-ray radiationInterelectrode capacitances
Plate resistance
1200 Ω
Max plate voltage
130 V
Max plate dissipation
0.5 W

Built-in control diode; second published plate-resistance value is condition-dependent and retained 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

Characteristic

  • Frequency for Maximum Ratings

    250 MHz

  • Filament/Heater Current

    7.15 A to 8.1 A

  • Amplification Factor

    10 to 13

  • Rated Heating Time

    1 s

  • Fast Warm-up Time

    0.15 s

    6.2 V

Other

  • Maximum DC Plate Current

    200 mA

    Power tetrode maximum

  • Absolute Maximum Filament Voltage for Fast Warm-up

    6.2 V

Capacitance

  • Input Capacitance

    26 pF

    Grounded cathode

  • Output Capacitance

    5.2 pF

    Grounded cathode; about 6.0 pF added to ground when chassis-mounted

  • Feedback Capacitance

    0.05 pF

    Grounded cathode

SECTION 2

Diode

Characteristic

  • Plate Resistance

    1600 ohm

    Id=0.01 A, Ec=-40 V

Other

  • Maximum DC Plate Current

    20 mA

Data set 02

1965 Eimac Tube Manual

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Characteristic

  • Heater/filament voltage

    2.1 V

  • Heater/filament current

    7.625 A

  • Amplification factor

    11.5

  • Transconductance

    20000 uS

  • Heating time at rated heater voltage

    1 s

  • Fast-start heating time

    0.15 s

    HeaterVoltage=6.2V

Capacitance

  • Input/grid-cathode capacitance

    16 pF

  • Output/plate-cathode capacitance

    4 pF

  • Feedback/grid-plate capacitance

    0.03 pF

Other

  • Maximum plate voltage

    2000 V

  • Maximum screen voltage

    400 V

  • Maximum plate dissipation

    100 W

  • Maximum screen dissipation

    8 W

  • Maximum grid dissipation

    0.5 W

  • Maximum plate/cathode current

    300 mA

  • Frequency for maximum ratings

    250 MHz

  • Fast-start heater voltage

    6.2 V

    FastStart

  • Typical RF plate voltage

    2000 V

    RF

  • Typical screen voltage

    400 V

    RF