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Power - Pentode (NOT beam) ·Pentode

6F6

Pentode power amplifier designed for receiver output stages, with documented single-ended Class-A and push-pull Class-A/AB operation. A classic non-beam audio power-output tube.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
7S
Socket code
IO
Base pins
8
Nominal heater
6.3 V / 700 mA

Description

The 6F6 is a pentode power amplifier intended for receiver power-output stages, with published single-ended Class A and push-pull Class A/AB operating conditions.

Socket description

International Octal

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
7S
Socket code
IO
Base pins
8
Nominal heater voltage
6.3 V
Nominal heater current
700 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

7S - Terminal pinout

Electrical assignments shared by every tube using this base designation.

TerminalSectionConnectionEvidence
PIN1ISAIS — Internal Screen

EIA chart transcription; independent manufacturer verification pending

Unverified

EIA Base Connections, printed page 128, 7S

PIN2H—H — Heater

EIA chart transcription; independent manufacturer verification pending

Unverified

EIA Base Connections, printed page 128, 7S

PIN3PAP — Plate (Anode)

EIA chart transcription; independent manufacturer verification pending

Unverified

EIA Base Connections, printed page 128, 7S

PIN4G2AG2 — Screen Grid

EIA chart transcription; independent manufacturer verification pending

Unverified

EIA Base Connections, printed page 128, 7S

PIN5G1AG1 — Control Grid

EIA chart transcription; independent manufacturer verification pending

Unverified

EIA Base Connections, printed page 128, 7S

PIN7H—H — Heater

EIA chart transcription; independent manufacturer verification pending

Unverified

EIA Base Connections, printed page 128, 7S

PIN8G3AG3 — Suppressor GridGroup 7S8

EIA chart transcription; independent manufacturer verification pending

Unverified

EIA Base Connections, printed page 128, 7S

PIN8KAK — CathodeGroup 7S8

EIA chart transcription; independent manufacturer verification pending

Unverified

EIA Base Connections, printed page 128, 7S

Section ratings

1 physical section, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances
Plate resistance
80000 Ω
Transconductance
0.0025 S
Amplification factor
200
Max plate voltage
375 V
Max screen voltage
285 V
Max plate dissipation
11 W
Max screen dissipation
3.75 W

Audio output pentode; triode-connected ratings are 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

1935 RCA All Metal Radio Tubes

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Plate voltage

    315 V

    ClassA;PentodeConnection

  • Screen voltage

    315 V

    ClassA;PentodeConnection

  • Grid voltage

    -22 V

    ClassA;PentodeConnection

  • Plate current

    42 mA

    ClassA;PentodeConnection

  • Screen current

    8 mA

    ClassA;PentodeConnection

  • Load resistance

    7000 Ohm

    ClassA;PentodeConnection

  • Power output

    5 W

    ClassA;PentodeConnection

  • Total harmonic distortion

    7 %

    ClassA;PentodeConnection

  • Power output

    19 W

    ClassAB;PushPull;TwoTubes;PentodeConnection

  • Plate voltage

    375 V

    ClassAB;PushPull;PentodeConnection

  • Screen voltage

    250 V

    ClassAB;PushPull;PentodeConnection

  • Power output

    18 W

    ClassAB;PushPull;TwoTubes;TriodeConnection

Data set 02

1937 Raytheon Radio Receiving Tubes

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Maximum Plate Voltage

    315 V

    Published table

  • Plate Voltage

    250 V

    ClassA; Column1

  • Plate Voltage

    316 V

    ClassA; Column2

  • Plate Voltage

    250 V

    ClassA; Column3

  • § Screen Voltage

    250 V

    ClassA; Column1

  • § Screen Voltage

    315 V

    ClassA; Column2

  • Plate Voltage

    375 V

    ClassA; Column1

  • Plate Voltage

    375 V

    ClassA; Column2

  • Plate Voltage

    350 V

    ClassA; Column3

  • Plate Voltage

    350 V

    ClassA; Column4

  • Screen Voltage

    250 V

    ClassA; Column1

  • Screen Voltage

    250 V

    ClassA; Column2

  • No=Signal Plate Current

    34 mA

    ClassA; Column1

  • No=Signal Plate Current

    54 mA

    ClassA; Column2

  • No=Signal Plate Current

    45 mA

    ClassA; Column3

  • No=Signal Plate Current

    50 mA

    ClassA; Column4

  • No-Signal Screen Current

    5 mA

    ClassA; Column1

  • No-Signal Screen Current

    8 mA

    ClassA; Column2

  • Load Resistance(P to P)

    10000 ohm

    ClassA; Column1

  • Load Resistance(P to P)

    10000 ohm

    ClassA; Column2

  • Load Resistance(P to P)

    6000 ohm

    ClassA; Column3

Data set 03

1940 RCA

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristics

  • Heater voltage

    6.3 V

    Published nominal value

  • Heater current

    700 mA

    Published nominal value

  • Transconductance

    2650 µS

    Published operating characteristic

  • Amplification factor

    200

    Published operating characteristic

Other

  • Audio power output

    4.5 W

    SingleTube; ClassA; 250 V plate

  • Load resistance

    7000 ohm

    SingleTube; ClassA

Data set 04

1950 Sylvania

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

  • Tension chauffage CA ou CC ... 6,3 6,3 volts

    6.3 V

    Tension chauffage CA ou CC ... 6,3 6,3 volts

  • Courant chauffage e e e e 0,7 0,7 ampére

    700 mA

    Courant chauffage e e e e 0,7 0,7 ampére

  • Tension chauffage CA ou CC ... ... .., 6,3 6,3 volts

    6.3 V

    Tension chauffage CA ou CC ... ... .., 6,3 6,3 volts

  • Courant chauffage e s 0,7 0,7 ampére

    700 mA

    Courant chauffage e s 0,7 0,7 ampére

  • Tension -chauffage ... ... .. 6,3 6,3 6,3 volts

    6.3 V

    Tension -chauffage ... ... .. 6,3 6,3 6,3 volts

  • Tension plaque ... ... .. .. 250 285 283 volts

    283 V

    Tension plaque ... ... .. .. 250 285 283 volts

  • Tension grille ... . —16,5 —20 —20 volts

    20 V

    Tension grille ... . —16,5 —20 —20 volts

  • Courant plaque (sngnal zéro)) 34 38- 31 ma.

    31 mA

    Courant plaque (sngnal zéro)) 34 38- 31 ma.

  • Résistance interne ... ... ... 80,000* 78,000* 2,600 ohms

    2.6 ohms

    Résistance interne ... ... ... 80,000* 78,000* 2,600 ohms

  • Conductance mutuelle v e 2,500 2,550 2,600 ymhos

    2.6 ymhos

    Conductance mutuelle v e 2,500 2,550 2,600 ymhos

  • Puissance modulée ... ... ... 3,2 4,8 0,85 watts

    0.85 W

    Puissance modulée ... ... ... 3,2 4,8 0,85 watts

  • Tension chauffage 6,3 6,3 6,3 volts

    6.3 V

    Tension chauffage 6,3 6,3 6,3 volts

  • Tension plaque 315 375 350 volts

    350 V

    Tension plaque 315 375 350 volts

  • Tension grille —24 —26 —38 volts

    38 V

    Tension grille —24 —26 —38 volts

  • Courant plaque (signal zéro) ... 62 34 48 ma.

    48 mA

    Courant plaque (signal zéro) ... 62 34 48 ma.

  • Tension plaque ... ... ... .. . . o L 250 volts

    250 V

    Tension plaque ... ... ... .. . . o L 250 volts

  • Tension grille —20 volts

    20 V

    Tension grille —20 volts

Other

  • Tension plaque ... ... .. . oo . 375 350 volts max.

    350 V

    Tension plaque ... ... .. . oo . 375 350 volts max.

  • Dissipation plaque 11 10 watts max.

    10 W

    Dissipation plaque 11 10 watts max.

  • Courant plaque (signal max.) ... 80 82 92 ma.

    92 mA

    Courant plaque (signal max.) ... 80 82 92 ma.

Data set 05

1953 RFT Rundfunk Technik

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • HeaterVoltageNominal

    6.3 V

    Nominal

  • HeaterCurrentNominal

    700 mA

    Nominal

  • Maximum Plate Voltage

    410 V

  • Maximum Screen Voltage

    315 V

  • Maximum Plate Dissipation

    12 W

  • Maximum Screen Dissipation

    2 W

Characteristic

  • Transconductance

    3000 µS

    Typical

  • Plate Resistance

    78000 ohm

    Typical

Data set 06

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Plate voltage

    285 V

    ClassA; SingleTube

  • Screen voltage

    285 V

    ClassA; SingleTube

  • Control-grid bias magnitude

    20 V

    ClassA; SingleTube

  • Plate current

    38 mA

    ClassA; SingleTube

  • Screen current

    7 mA

    ClassA; SingleTube

  • Plate resistance

    78000 ohm

    ClassA; SingleTube

  • Transconductance

    2550 uS

    ClassA; SingleTube

  • Load resistance

    7000 ohm

    ClassA; SingleTube

  • Power output

    4.8 W

    ClassA; SingleTube

  • Plate voltage

    250 V

    ClassA; SingleTube

  • Screen voltage

    250 V

    ClassA; SingleTube

  • Control-grid bias magnitude

    16.5 V

    ClassA; SingleTube

  • Plate current

    34 mA

    ClassA; SingleTube

  • Screen current

    6.5 mA

    ClassA; SingleTube

  • Plate resistance

    80000 ohm

    ClassA; SingleTube

  • Transconductance

    2500 uS

    ClassA; SingleTube

  • Load resistance

    7000 ohm

    ClassA; SingleTube

  • Power output

    3.2 W

    ClassA; SingleTube

Data set 07

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Power Output

    3.2 W

    ClassA;PentodeConnection

  • Power Output

    18.5 W

    ClassAB;PushPull;PentodeConnection

  • Power Output

    13 W

    ClassAB;PushPull;TriodeConnection

Data set 08

1966 Tung Sol Electronic Tubes 2 of 4

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Plate_voltage

    250 V

    ClassA,OneTube

  • Screen_voltage

    250 V

    ClassA,OneTube

  • Control_grid_voltage

    -16.5 V

    ClassA,OneTube

  • Load_resistance

    7000 ohm

    ClassA,OneTube

  • Power_output

    3.2 W

    ClassA,OneTube

  • Total_harmonic_distortion

    8 percent

    ClassA,OneTube

  • Plate_voltage

    375 V

    PushPull,TwoTubes,ClassAB

  • Screen_voltage

    250 V

    PushPull,TwoTubes,ClassAB

  • Power_output

    18.5 W

    PushPull,TwoTubes,ClassAB

  • Effective_load_resistance_plate_to_plate

    10000 ohm

    PushPull,TwoTubes,ClassAB

Characteristic

  • Zero_signal_plate_current

    34 mA

    ClassA,OneTube

  • Zero_signal_screen_current

    6.5 mA

    ClassA,OneTube