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Power - Beam (NOT sweep) ·BeamPower

25L6

Beam-power output tube designed for low-voltage Class-A audio amplifier service in AC/DC receiving equipment.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
7AC
Socket code
IO
Base pins
-
Nominal heater
25 V / 300 mA

Description

Beam power output tube for AC/DC audio amplifier service.

Socket description

International Octal

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
7AC
Socket code
IO
Base pins
-
Nominal heater voltage
25 V
Nominal heater current
300 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

7AC - Terminal pinout

Electrical assignments shared by every tube using this base designation.

TerminalSectionConnectionEvidence
PIN1Pin 1—NCVerified

12L6GT/25L6GT manufacturer basing, 7AC

PIN2Pin 2—H — HeaterVerified

12L6GT/25L6GT manufacturer basing, 7AC

PIN3Pin 3AP — Plate (Anode)Verified

12L6GT/25L6GT manufacturer basing, 7AC

PIN4Pin 4AG2 — Screen GridVerified

12L6GT/25L6GT manufacturer basing, 7AC

PIN5Pin 5AG1 — Control GridVerified

12L6GT/25L6GT manufacturer basing, 7AC

PIN7Pin 7—H — HeaterVerified

12L6GT/25L6GT manufacturer basing, 7AC

PIN8Pin 8ABP — Beam-Forming PlateGroup AC8Verified

12L6GT/25L6GT manufacturer basing, 7AC

PIN8Pin 8AK — CathodeGroup AC8Verified

12L6GT/25L6GT manufacturer basing, 7AC

Section ratings

1 physical section, each with unique specifications.

Section 1

Beam Power

X-ray radiationInterelectrode capacitances
Plate resistance
30000 Ω
Transconductance
0.0095 S
Amplification factor
82
Max plate voltage
200 V
Max screen voltage
117 V

Beam-power amplifier section.

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

1937 Raytheon Radio Receiving Tubes

Published operating points and test conditions from this source.

SECTION 1

Beam Power

Other

  • Maximum Plate Voltage

    110 V

    Published ratings

  • Maximum Screen Voltage

    110 V

    Published ratings

  • Plate Voltage

    110 V

    ClassA; Column1

  • Plate Voltage

    110 V

    ClassA; Column2

  • Screen Voltage

    110 V

    ClassA; Column1

  • Screen Voltage

    110 V

    ClassA; Column2

  • Grid Bias

    -7.5 V

    ClassA; Column1

  • Grid Bias

    -7.5 V

    ClassA; Column2

  • Signal Peak Voltage

    7.5 V

    ClassA; Column1

  • Signal Peak Voltage

    7.6 V

    ClassA; Column2

  • Amplification Factor

    82

    ClassA; Column1

  • Amplification Factor

    82

    ClassA; Column2

  • Plate Resistance {approx

    10000 ohm

    ClassA; Column1

  • Plate Resistance {approx

    10000 ohm

    ClassA; Column2

  • Transconductance

    8200 uS

    ClassA; Column1

  • Transconductance

    8200 uS

    ClassA; Column2

  • No-Signal Plate Current

    49 mA

    ClassA; Column1

  • No-Signal Plate Current

    49 mA

    ClassA; Column2

  • Maximum-Signal Plate Current

    54 mA

    ClassA; Column1

  • Maximum-Signal Plate Current

    50 mA

    ClassA; Column2

  • No-Signal Screen Current

    4 mA

    ClassA; Column1

  • No-Signal Screen Current

    4 mA

    ClassA; Column2

  • Maximum-Signal Screen Current

    9 mA

    ClassA; Column1

  • Maximum-Signal Screen Current

    11 mA

    ClassA; Column2

  • Load Resistance

    1500 ohm

    ClassA; Column1

  • Load Resistance

    2000 ohm

    ClassA; Column2

  • Total Harmonic Distortion

    11 %

    ClassA; Column1

  • Total Harmonic Distortion

    10 %

    ClassA; Column2

  • Second Harmonic Distortion

    10 %

    ClassA; Column1

  • Second Harmonic Distortion

    3.5 %

    ClassA; Column2

  • Third Harmonic Distortion

    4 %

    ClassA; Column1

  • Third Harmonic Distortion

    8.5 %

    ClassA; Column2

  • Power Output

    2.1 W

    ClassA; Column1

  • Power Output

    2.2 W

    ClassA; Column2

  • The voltage between heater and cathode should not exceed

    90 V

    ClassA

Data set 02

1940 RCA

Published operating points and test conditions from this source.

SECTION 1

Beam Power

Other

  • The

    7

    The 25L6 is a power-amplifier tube MO, 7O

  • HEeATER VOLTAGE (A. C.or D.C).....ooinnn

    25 V

    HEeATER VOLTAGE (A. C.or D.C).....ooinnn 25.0 Volts

  • HEATER CURRENT . .ivivvninonrnnnnnanocasonens

    300 mA

    HEATER CURRENT . .ivivvninonrnnnnnanocasonens 0.3 Ampere

  • PLATE VOLTAGE .......cocvvvnnuunnen

    110 V

    PLATE VOLTAGE .......cocvvvnnuunnen. . 110 110 Volts

  • ScREEN VOLTAGE (Grid No

    110 V

    ScREEN VOLTAGE (Grid No. 2)........... 110 110 Volts

  • GRID VOLTAGE (Grid No

    -17.5 V

    GRID VOLTAGE (Grid No. 1).............. -7.5 -17.5 Volts

  • PEAR A‘F GRID VOLTAGE. ... vvvvnnnnn

    7.5 V

    PEAR A‘F GRID VOLTAGE. ... vvvvnnnnn... 7.5 7.5 Volts

  • ZERO-SIGNAL PLATE CURRENT

    49

    ZERO-SIGNAL PLATE CURRENT............. 49 49 Milliamperes

  • MAX.-SIGNAL PLATE CURRENT

    50

    MAX.-SIGNAL PLATE CURRENT............. 54 50 Milliamperes

  • ZERO-SIGNAL SCREEN CURRENT

    4

    ZERO-SIGNAL SCREEN CURRENT............ 4 4 Milliamperes

  • MAX.-SIGNAL SCREEN CURRENT

    11

    MAX.-SIGNAL SCREEN CURRENT............ 9 11 Milliamperes

  • PowER OUTPUT ........ccoivvvinnnnnn

    2.2 W

    PowER OUTPUT ........ccoivvvinnnnnn. 2.1 2.2 Watts

Characteristic

  • PLATE RESISTANCE (Approx.)

    10000 ohm

    PLATE RESISTANCE (Approx.)............. 10000 10000 Ohms

  • LoAD RESISTANCE

    2000 ohm

    LoAD RESISTANCE ...................-.. 1500 2000 Ohms

  • 0.5 megohm. A family of plate characteristic curves is given

    0.5

    0.5 megohm. A family of plate characteristic curves is given on the preceding page

Data set 03

1950 Sylvania

Published operating points and test conditions from this source.

SECTION 1

Beam Power

Application

  • Service

    Audio power output

Data set 04

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Beam Power

Capacitance

  • Input capacitance

    16 pF

  • Output capacitance

    13.5 pF

  • Grid-to-plate capacitance

    0.3 pF

Other

  • Plate voltage

    200 V

    ClassA

  • Screen-grid voltage

    110 V

    ClassA

  • Grid voltage

    -8 V

    ClassA

  • Plate current

    50 mA

    ClassA

  • Screen-grid current

    2 mA

    ClassA

  • Load resistance

    3000 ohm

    ClassA

  • Power output

    4.3 W

    ClassA

  • Plate voltage

    110 V

    ClassA;LowVoltage

  • Screen-grid voltage

    110 V

    ClassA;LowVoltage

  • Grid voltage

    -7.5 V

    ClassA;LowVoltage

  • Plate current

    49 mA

    ClassA;LowVoltage

  • Screen-grid current

    4 mA

    ClassA;LowVoltage

  • Load resistance

    2000 ohm

    ClassA;LowVoltage

  • Power output

    2.1 W

    ClassA;LowVoltage

Characteristic

  • Plate resistance

    30000 ohm

    ClassA;PlateVoltage=200V

  • Transconductance

    9500 uS

    ClassA;PlateVoltage=200V

  • Plate resistance

    13000 ohm

    ClassA;LowVoltage

  • Transconductance

    9000 uS

    ClassA;LowVoltage