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Voltage Radio Detector Converter ·Pentode-Triode

5B8

Medium-mu triode and sharp-cutoff pentode for VHF oscillator and mixer service.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
9EC
Socket code
B9A
Base pins
9
Nominal heater
4.7 V / 600 mA

Description

5B8 is described in the supplied Tung-Sol datasheet as a medium-mu triode and sharp-cutoff pentode for VHF oscillator/mixer service. The redo includes a substantive section-electrical extraction from ratings and characteristic tables.

Socket description

Small-button Noval 9-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
9EC
Socket code
B9A
Base pins
9
Nominal heater voltage
4.7 V
Nominal heater current
600 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

9EC - Terminal pinout

Electrical assignments shared by every tube using this base designation.

TerminalSectionConnectionEvidence
PIN1Pin 1AG3 — Suppressor GridGroup 9EC1

Original chart label: 1G3; manufacturer verification pending

Unverified

EIA Base Connections, printed page 132, 9EC

PIN1Pin 1BK — CathodeGroup 9EC1

Original chart label: 2K; manufacturer verification pending

Unverified

EIA Base Connections, printed page 132, 9EC

PIN1Pin 1—IS — Internal ScreenGroup 9EC1

Original chart label: IS; manufacturer verification pending

Unverified

EIA Base Connections, printed page 132, 9EC

PIN2Pin 2BG1 — Control Grid

Original chart label: 2G1; manufacturer verification pending

Unverified

EIA Base Connections, printed page 132, 9EC

PIN3Pin 3BP — Plate (Anode)

Original chart label: 2P; manufacturer verification pending

Unverified

EIA Base Connections, printed page 132, 9EC

PIN4Pin 4—H — Heater

Original chart label: H; manufacturer verification pending

Unverified

EIA Base Connections, printed page 132, 9EC

PIN5Pin 5—H — Heater

Original chart label: H; manufacturer verification pending

Unverified

EIA Base Connections, printed page 132, 9EC

PIN6Pin 6AG1 — Control Grid

Original chart label: 1G1; manufacturer verification pending

Unverified

EIA Base Connections, printed page 132, 9EC

PIN7Pin 7AK — Cathode

Original chart label: 1K; manufacturer verification pending

Unverified

EIA Base Connections, printed page 132, 9EC

PIN8Base PinAG2 — Screen Grid

Original chart label: 1G2; manufacturer verification pending

Unverified

EIA Base Connections, printed page 132, 9EC

PIN9Base PinAP — Plate (Anode)

Original chart label: 1P; manufacturer verification pending

Unverified

EIA Base Connections, printed page 132, 9EC

Section ratings

2 physical sections, each with unique specifications.

Section 1

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
5750 Ω
Transconductance
0.0033 S
Amplification factor
19
Max plate voltage
300 V
Max plate dissipation
2.6 W
Rectifier max heater-cathode voltage
200 V
Rectifier warm-up time
11 s

Published medium-mu triode Class A1 characteristics.

Section 2

Pentode

X-ray radiationInterelectrode capacitances
Plate resistance
300000 Ω
Transconductance
0.0062 S
Max plate voltage
300 V
Max screen voltage
300 V
Max plate dissipation
2 W
Max screen dissipation
0.5 W
Rectifier max heater-cathode voltage
200 V
Rectifier warm-up time
11 s

Published sharp-cutoff pentode Class A1 characteristics.

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

1950 Sylvania

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Heater Voltage

    4.7 V

    Nominal

  • Heater Current

    600 mA

    Nominal

  • Plate Voltage

    200 V

    ClassA

  • Plate Current

    13 mA

    ClassA

SECTION 2

Pentode

Other

  • Plate Voltage

    200 V

    ClassA

  • Screen Voltage

    150 V

    ClassA

  • Plate Current

    9.5 mA

    ClassA

  • Screen Current

    2.8 mA

    ClassA

Data set 02

1966 Tung Sol Electronic Tubes 1 of 4

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristic

  • Heater/filament voltage

    4.7 V

    Published rating

  • Heater/filament current

    600 mA

    Published rating

  • Heater warm-up

    Controlled

    SeriesHeater

Other

  • Application

    VHF oscillator and mixer

    TelevisionService

Data set 03

1971 RCA HB3 Binder 4 of 7

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Plate supply voltage

    200 V

    ClassA1

  • Grid voltage

    -6 V

    ClassA1

  • Plate current

    13 mA

    ClassA1

  • Maximum fixed-bias grid circuit resistance

    0.5 Mohm

  • Maximum cathode-bias grid circuit resistance

    1 Mohm

Characteristic

  • Plate resistance

    5750 ohm

    ClassA1

  • Transconductance

    3300 uS

    ClassA1

  • Amplification factor

    19

    ClassA1

  • Grid-to-plate capacitance

    1.7 pF

  • Grid-to-cathode/heater capacitance

    1.9 pF

  • Plate-to-cathode/heater capacitance

    1.4 pF

  • Heater warm-up time

    11 s

    ControlledWarmUp

SECTION 2

Pentode

Other

  • Plate supply voltage

    200 V

    ClassA1

  • Grid 2 supply voltage

    150 V

    ClassA1

  • Cathode resistor

    180 ohm

    ClassA1

  • Plate current

    9.5 mA

    ClassA1

  • Grid 2 current

    2.8 mA

    ClassA1

  • Maximum fixed-bias grid circuit resistance

    0.25 Mohm

  • Maximum cathode-bias grid circuit resistance

    1 Mohm

Characteristic

  • Plate resistance

    300000 ohm

    ClassA1

  • Transconductance

    6200 uS

    ClassA1

  • Grid 1 cutoff reference voltage

    -8 V

    ClassA1

  • Grid 1-to-plate capacitance

    0.05 pF

  • Grid 1 input capacitance

    6 pF

  • Plate output capacitance

    2.6 pF

  • Plate-to-cathode/grid2/heater capacitance

    0.15 pF