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Power - Pentode (NOT beam) ·Pentode

2A5

Power/output pentode designed for Class-A, single-ended, or push-pull audio-frequency output amplification.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
6B
Socket code
UX6
Base pins
6
Nominal heater
2.5 V / 1.75 A

Description

Pentode power amplifier for receiver power-output stages; electrically identical to 6F6/42 types except for heater ratings.

Socket description

Small 6-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
6B
Socket code
UX6
Base pins
6
Nominal heater voltage
2.5 V
Nominal heater current
1.75 A
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

6B - Terminal pinout

Electrical assignments shared by every tube using this base designation.

No verified pinout is recorded for this base designation.

Section ratings

1 physical section, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances
Plate resistance
80000 Ω
Transconductance
0.0026 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

Pentode-connection maxima; triode-connection operation is preserved in 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

1937 Raytheon Radio Receiving Tubes

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Maximum plate voltage

    315 V

    Published datasheet rating

  • Maximum screen voltage

    315 V

    Published datasheet rating

  • Plate voltage

    250 V

    ClassA

  • Screen voltage

    250 V

    ClassA

  • Control-grid bias

    16.5 V

    ClassA

  • Plate current

    34 mA

    ClassA

  • Screen current

    6.5 mA

    ClassA

  • Load resistance

    7000 ohm

    ClassA

  • Power output

    3 W

    ClassA

  • Triode-connected plate voltage

    315 V

    TriodeConnection ClassA

  • Triode-connected grid bias

    20 V

    TriodeConnection ClassA

  • Triode-connected load resistance

    4000 ohm

    TriodeConnection ClassA

  • Triode-connected power output

    0.85 W

    TriodeConnection ClassA

  • Push-pull pentode plate voltage

    375 V

    ClassAB PushPull TwoTubes

  • Push-pull pentode power output

    19 W

    ClassAB PushPull TwoTubes

Characteristic

  • Plate resistance

    80000 ohm

    Published datasheet characteristic

  • Transconductance

    2500 µS

    Published datasheet characteristic

  • Amplification factor

    200

    Published datasheet characteristic

  • Heater/filament voltage

    2.5 V

    Published heater/filament rating

  • Heater/filament current

    1.75 A

    Published heater/filament rating

  • Triode-connected plate resistance

    2600 ohm

    TriodeConnection

  • Triode-connected transconductance

    2700 µS

    TriodeConnection

Data set 02

1940 RCA

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • HEATER VOLTAGE (A. C.or D.C) ...t

    2.5 V

    HEATER VOLTAGE (A. C.or D.C) ...t 2.5 Volts

  • HEATER CURRENT ..ovnirunniunnonennnncoannss

    1.75 A

    HEATER CURRENT ..ovnirunniunnonennnncoannss 1.75 Amperes

  • The heater is designed to operate at

    2.5 V

    The heater is designed to operate at 2.5 volts. The transformer winding

  • E¢=

    2.5 V

    E¢=63 VOLTS E¢=2.5 VOLTS

  • (1,c2) MILLIAMPERES

    1

    (1,c2) MILLIAMPERES

  • PLATE AND SCREEN VOLTS

    5232 V

    PLATE AND SCREEN VOLTS 92Cc—5232

Data set 03

1948 Brimar Radio Valve Manual

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

  • HeaterOrFilamentVoltage

    2.5 V

  • HeaterOrFilamentCurrent

    1.75 A

Data set 04

1950 Sylvania

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

  • Tension de chauffage (CA. ou CC) ... ... ... .. 2,5 volts

    2.5 V

    Tension de chauffage (CA. ou CC) ... ... ... .. 2,5 volts

Data set 05

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Plate voltage

    285 V

    ClassA

  • Screen voltage

    285 V

    ClassA

  • Control-grid voltage

    -20 V

    ClassA

  • Plate current

    38 mA

    ClassA

  • Screen current

    7 mA

    ClassA

  • Load resistance

    7000 Ω

    ClassA

  • Power output

    4.8 W

    ClassA

  • Plate voltage

    250 V

    ClassA TriodeConnection

  • Control-grid voltage

    -20 V

    ClassA TriodeConnection

  • Plate current

    31 mA

    ClassA TriodeConnection

  • Load resistance

    4000 Ω

    ClassA TriodeConnection

  • Power output

    0.85 W

    ClassA TriodeConnection

Characteristic

  • Plate resistance

    78000 Ω

    ClassA

  • Transconductance

    2500 µS

    ClassA

  • Plate resistance

    2600 Ω

    ClassA TriodeConnection

  • Transconductance

    2600 µS

    ClassA TriodeConnection

  • Amplification factor

    6.8

    ClassA TriodeConnection

Data set 06

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Plate Voltage

    250 V

    ClassA;SingleTube;PentodeConnection

  • Screen Voltage

    250 V

    ClassA;SingleTube;PentodeConnection

  • Load Resistance

    7000 ohm

    ClassA;SingleTube;PentodeConnection

  • Power Output

    3.2 W

    ClassA;SingleTube;PentodeConnection

  • Power Output

    18.5 W

    ClassAB;PushPull;TwoTubes;PentodeConnection

  • Power Output

    13 W

    ClassAB;PushPull;TwoTubes;TriodeConnection

Data set 07

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;SingleTube

  • Screen voltage

    250 V

    ClassA;SingleTube

  • Control grid voltage

    -16.5 V

    ClassA;SingleTube

  • Zero-signal plate current

    34 mA

    ClassA;SingleTube

  • Zero-signal screen current

    6.5 mA

    ClassA;SingleTube

  • Maximum-signal plate current

    36 mA

    ClassA;SingleTube

  • Maximum-signal screen current

    10.5 mA

    ClassA;SingleTube

  • Load resistance

    7000 ohm

    ClassA;SingleTube

  • Power output

    3.2 W

    ClassA;SingleTube

  • Total harmonic distortion

    8 %

    ClassA;SingleTube

  • Effective plate-to-plate load resistance

    10000 ohm

    PushPull;TwoTubes;ClassA

  • Power output

    11 W

    PushPull;TwoTubes;ClassA