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Voltage Tetrode ·Tetrode

3CY5

VHF tetrode designed as the RF amplifier in television tuners, providing high-frequency gain with controlled cutoff characteristics for front-end receiver service.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
7EW
Socket code
B7G
Base pins
7
Nominal heater
2.9 V / 600 mA

Description

A sharp-cutoff tetrode intended for VHF RF amplification in television tuners.

Socket description

Miniature 7-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
7EW
Socket code
B7G
Base pins
7
Nominal heater voltage
2.9 V
Nominal heater current
600 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

7EW - Terminal pinout

Electrical assignments shared by every tube using this base designation.

TerminalSectionConnectionEvidence
PIN1G1AG1 — Control Grid

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 7EW

PIN2ISAIS — Internal ScreenGroup 7EW2

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 7EW

PIN2KAK — CathodeGroup 7EW2

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 7EW

PIN3H—H — Heater

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 7EW

PIN4H—H — Heater

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 7EW

PIN5PAP — Plate (Anode)

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 7EW

PIN6G2AG2 — Screen Grid

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 7EW

PIN7ISAIS — Internal ScreenGroup 7EW7

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 7EW

PIN7KAK — CathodeGroup 7EW7

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 7EW

Section ratings

1 physical section, each with unique specifications.

Section 1

Tetrode

X-ray radiationInterelectrode capacitances
Plate resistance
125000 Ω
Transconductance
0.008 S
Max plate voltage
180 V
Max screen voltage
180 V
Max plate dissipation
2 W
Max screen dissipation
0.5 W
Max cathode current
20 mA

Published section ratings promoted where explicitly available; additional source values retained in parameter rows.

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

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Other

  • PLATE VOLTAGE

    108 VOLTS

    Published datasheet value

  • PLATE CURRENT

    10 MA

    Published datasheet value

Data set 02

1965 Sylvania Electronic Tubes Vol3

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Other

  • Plate voltage

    125 V

  • Screen-grid voltage

    80 V

  • Grid 1 voltage

    -1 V

  • Plate current

    10 mA

  • Screen-grid current

    1.4 mA

Characteristics

  • Plate resistance

    125000 Ohm

  • Transconductance

    8000 uS

  • Control-grid cutoff voltage

    -6 V

Capacitance

  • Grid-to-plate capacitance

    0.03 pF

    Shielded

  • Input capacitance

    4.4 pF

    Shielded

  • Output capacitance

    2.8 pF

    Shielded

Data set 03

1966 Tung Sol Electronic Tubes 1 of 4

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Characteristic

  • Heater voltage

    2.9 V

    Published heater rating

  • Heater current

    600 mA

    Published heater rating

Other

  • Maximum plate voltage

    150 V

    Published limit

  • Maximum screen supply voltage

    150 V

    Published limit

  • Maximum plate dissipation

    2 W

    Published limit

  • Maximum screen dissipation

    0.5 W

    Published limit

  • Maximum cathode current

    20 mA

    Published limit

Data set 04

1971 RCA HB3 Binder 4 of 7

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Characteristics

  • Current — published value 1

    0.45

    Published datasheet value; multiple numbers on a row represent separate source limits or conditions.

  • Current — published value 2

    0.03

    Published datasheet value; multiple numbers on a row represent separate source limits or conditions.

  • Voltage (ac or dc) at 0.450 A — published value 1

    0 V

    Published datasheet value; multiple numbers on a row represent separate source limits or conditions.

  • Voltage (ac or dc) at 0.450 A — published value 2

    0.45 V

    Published datasheet value; multiple numbers on a row represent separate source limits or conditions.

  • Voltage (ac or dc) at 0.450 A — published value 3

    2.9 V

    Published datasheet value; multiple numbers on a row represent separate source limits or conditions.

Data set 05

1975 RCA RC30

Published operating points and test conditions from this source.

SECTION 1

Tetrode

Characteristic

  • Heater warm-up time

    11 s

    ClassA

  • Plate voltage

    125 V

    ClassA

  • Plate current

    10 mA

    ClassA

  • Grid 2 current

    1.5 mA

    ClassA

Capacitance

  • Grid 1 to plate capacitance

    0.03 pF