Skip to main content
Tube Tinker — Electron Tube Database
Alternatives & variationsDownload PDF datasheet

Voltage - Triode (single high frequency) ·Triode

6FQ5A

High-mu frame-grid miniature triode used as a grounded-cathode RF amplifier in VHF television tuners.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
7FP
Socket code
B7G
Base pins
7
Nominal heater
6.3 V / 180 mA

Description

High-mu frame-grid miniature triode used as a grounded-cathode RF amplifier in VHF 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
7FP
Socket code
B7G
Base pins
7
Nominal heater voltage
6.3 V
Nominal heater current
180 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

7FP - Terminal pinout

Electrical assignments shared by every tube using this base designation.

TerminalSectionConnectionEvidence
PIN1KAK — Cathode

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 7FP

PIN2G1AG1 — Control Grid

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 7FP

PIN3H—H — Heater

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 7FP

PIN4H—H — Heater

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 7FP

PIN5PAP — Plate (Anode)

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 7FP

PIN6ISAIS — Internal Screen

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 7FP

PIN7KAK — Cathode

EIA transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 7FP

Section ratings

1 physical section, each with unique specifications.

Section 1

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
6300 Ω
Transconductance
0.012 S
Amplification factor
74
Max plate voltage
250 V
Max plate dissipation
2.5 W
Max cathode current
22 mA

Promoted Class A1 characteristics at 135 V plate and design-maximum ratings.

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

1966 Tung Sol Electronic Tubes 2 of 4

Published operating points and test conditions from this source.

SECTION 1

Triode

Capacitance

  • Grid-to-plate capacitance

    0.42 pF

  • Input capacitance

    5 pF

  • Output capacitance

    3.5 pF

  • Heater-to-cathode capacitance

    2.5 pF

Other

  • Plate voltage

    135 V

    ClassA

  • Grid voltage

    -1.2 V

    ClassA

  • Plate current

    8.3 mA

    ClassA

Characteristic

  • Transconductance

    12000 uS

    ClassA

  • Amplification factor

    74

    ClassA

  • Plate resistance

    6300 ohm

    ClassA

  • Grid voltage at 100 uA plate current

    -4.5 V

Data set 02

1971 RCA HB3 Binder 4 of 7

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Heater voltage nominal

    6.3 V

  • Heater voltage tolerance

    0.6 V

    ±

  • Heater current

    180 mA

    HeaterVoltage=6.3V

  • Peak heater-cathode voltage, heater negative

    100 V

  • Peak heater-cathode voltage, heater positive

    100 V

  • Maximum plate voltage

    200 V

    ClassA1

  • Maximum negative grid-bias magnitude

    50 V

    ClassA1

  • Maximum cathode current

    22 mA

    ClassA1

  • Maximum plate dissipation

    2.5 W

    ClassA1

  • Maximum grid-circuit resistance

    1 MΩ

    ClassA1;CathodeBias

Capacitance

  • Grid-to-plate capacitance

    0.52 pF

  • Grid-to-cathode/internal-shield/heater capacitance

    5 pF

  • Plate-to-cathode/internal-shield/heater capacitance

    3.5 pF

  • Heater-to-cathode capacitance

    2.5 pF

    ExternalShield=Ground

Characteristics

  • Plate voltage

    135 V

    ClassA1

  • Grid voltage

    -1.2 V

    ClassA1

  • Amplification factor

    74

    ClassA1

  • Plate resistance

    6300 ohm

    ClassA1

  • Transconductance

    12000 µS

    ClassA1

  • Plate current

    8.9 mA

    ClassA1

  • Grid voltage for plate current 100 µA

    -4.5 V

    ClassA1

Data set 03

1975 RCA RC30

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Heater Voltage (ac/dc) 2.3 2.8 4

    6.3 V

    Published in approved 2GK5 target datasheet entry; Section1

  • Heater Current 0.6 0.45 0.3

    180 mA

    Published in approved 2GK5 target datasheet entry; Section1

  • Negative-bias value

    50 V

    Published in approved 2GK5 target datasheet entry; Section1

  • Positive-bias value

    0 V

    Published in approved 2GK5 target datasheet entry; Section1

  • Average Cathode Current

    22 mA

    Published in approved 2GK5 target datasheet entry; Section1

  • Plate Dissipation

    2.5 W

    Published in approved 2GK5 target datasheet entry; Section1

  • Plate Voltage

    135 V

    Published in approved 2GK5 target datasheet entry; Section1

  • Grid Voltage

    -1 V

    Published in approved 2GK5 target datasheet entry; Section1

  • Plate Resistance (Approx.)

    5400 Ω

    Published in approved 2GK5 target datasheet entry; Section1

  • Transconductan'*.e

    15000 µS

    Published in approved 2GK5 target datasheet entry; Section1

  • Plate Current

    11.5 mA

    Published in approved 2GK5 target datasheet entry; Section1

  • Grid-Circuit Resistance, for cathode-bias operation

    1 MΩ

    Published in approved 2GK5 target datasheet entry; Section1

  • • Measured at

    200 MHz

    Published in approved 2GK5 target datasheet entry; Section1

  • f For a neutralized triode amplifier at a frequency of

    200 MHz

    Published in approved 2GK5 target datasheet entry; Section1

  • Heater Voltage (ac/dc) 6.3 10

    16 V

    Published in approved 2GK5 target datasheet entry; Section1

  • Heater Current 0.76 0.45

    300 mA

    Published in approved 2GK5 target datasheet entry; Section1

  • 11

    11 seconds

    Published in approved 2GK5 target datasheet entry; Section1

  • Plate Supply Voltage

    605 V

    Published in approved 2GK5 target datasheet entry; Section1

  • Plate Voltage

    330 V

    Published in approved 2GK5 target datasheet entry; Section1

  • Grid-No.2 Supply Voltage

    605 V

    Published in approved 2GK5 target datasheet entry; Section1

  • Grid-No.2 (Screen-Grid) Voltage

    330 V

    Published in approved 2GK5 target datasheet entry; Section1

  • Grid-No.l (Control-Grid) Voltage, Negative-bias value

    100 V

    Published in approved 2GK5 target datasheet entry; Section1

  • Cathode Current

    65 mA

    Published in approved 2GK5 target datasheet entry; Section1

  • Plate Dissipation

    13.2 W

    Published in approved 2GK5 target datasheet entry; Section1

  • Grid-No.2 Input, Peak

    4 W

    Published in approved 2GK5 target datasheet entry; Section1

  • Grid-No.2 Input, Average

    2 W

    Published in approved 2GK5 target datasheet entry; Section1

  • Plate Supply Voltage

    250 V

    Published in approved 2GK5 target datasheet entry; Section1

  • Grid-No.2 Supply Voltage

    250 V

    Published in approved 2GK5 target datasheet entry; Section1

  • Cathode-Bias Resistor

    135 Ω

    Published in approved 2GK5 target datasheet entry; Section1

  • Plate Resistance (Approx.)

    38000 Ω

    Published in approved 2GK5 target datasheet entry; Section1

  • Transconductance

    11300 µS

    Published in approved 2GK5 target datasheet entry; Section1

  • Peak AF Grid-No.l Voltage

    7.3 V

    Published in approved 2GK5 target datasheet entry; Section1

  • Zero-Signal Plate Current

    48 mA

    Published in approved 2GK5 target datasheet entry; Section1

  • Maximum-Signal Plate Current

    50.6 mA

    Published in approved 2GK5 target datasheet entry; Section1

  • Zero-Signal Grid-No.2 Current

    5.5 mA

    Published in approved 2GK5 target datasheet entry; Section1

  • Maximum-Signal Grid-No.2 Current

    10 mA

    Published in approved 2GK5 target datasheet entry; Section1

  • Effective Load Resistance

    5200 Ω

    Published in approved 2GK5 target datasheet entry; Section1

Capacitance

  • Grid to Plate

    0.62 pF

    Published in approved 2GK5 target datasheet entry; Section1

  • Grid to Cathode, Heater, and Internal Shield

    5 pF

    Published in approved 2GK5 target datasheet entry; Section1

  • Plate to Cathode, Heater, and Internal Shield

    3.5 pF

    Published in approved 2GK5 target datasheet entry; Section1

  • Internal Shield

    10 pF

    Published in approved 2GK5 target datasheet entry; Section1

  • Internal Shield

    7 pF

    Published in approved 2GK5 target datasheet entry; Section1

Characteristic

  • Input Resistance*

    275 Ω

    Published in approved 2GK5 target datasheet entry; Section1

  • Input Capacitance*

    11.2 pF

    Published in approved 2GK5 target datasheet entry; Section1

  • Grid Voltage (Approx.) for transconductance of

    1500 µS

    Published in approved 2GK5 target datasheet entry; Section1

  • Grid Voltage (Approx.) for transconductance of 1500 /imhos

    -2.5 V

    Published in approved 2GK5 target datasheet entry; Section1