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Voltage Pentode - High Frequency (single) ·Pentode

KF4

Low-current directly heated battery pentode for fixed-gain high-frequency amplification in economical portable receiver circuitry.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
-
Base pins
-
Nominal heater
2 V / 65 mA

Description

KF4 is listed in the supplied valve table as a HF pentode. Published operating and characteristic values were transcribed from its target row.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
-
Base pins
-
Nominal heater voltage
2 V
Nominal heater current
65 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

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
1000000 Ω
Transconductance
0.0008 S
Max plate voltage
135 V
Max screen voltage
135 V
Max plate dissipation
0.5 W
Max screen dissipation
0.25 W
Max cathode current
5 mA

Published target-row operating and characteristic values reviewed.

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

1938 Philips Miniwatt Vacuum Tube Catalog

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Plate voltage

    135 V

    Published table operating point

  • Screen voltage

    135 V

    Published table operating point

  • Plate current

    2.6 mA

    Published table operating point

  • Control-grid bias

    0.1 V

    Published table operating point

  • Alternate plate voltage

    90 V

    OperatingPoint2

  • Alternate screen voltage

    90 V

    OperatingPoint2

  • Alternate plate current

    1.2 mA

    OperatingPoint2

  • Alternate control-grid bias

    0.15 V

    OperatingPoint2

Characteristic

  • Plate resistance

    1000000 ohm

    Published table characteristic

  • Transconductance

    800 µS

    Published table characteristic

  • Heater/filament voltage

    2 V

    Published heater/filament rating

  • Heater/filament current

    65 mA

    Published heater/filament rating

  • Alternate transconductance

    900 µS

    OperatingPoint2

Data set 02

1999 Philips E-Z

Published operating points and test conditions from this source.

SECTION 1

Pentode

Capacitance

  • Filament voltage. Vi

    20 V

    ClassB

  • Filament current. Iy

    65 mA

Other

  • Va = max

    135 V

  • Wa = max

    0.5 W

  • Vya = max

    135 V

  • I ¢ Wy = max

    0.25 W

  • Iy Iy, = max

    5 mA

  • Anode voltage [1]

    90 V

  • Anode voltage [2]

    135 V

  • Sereen-grid voltage [1]

    90 V

  • Sereen-grid voltage [2]

    135 V

  • Grid bias. — [1]

    0.5 V

  • Grid bias. — [2]

    5 V

  • Anode current [1]

    1.2 mA

  • Anode current [2]

    2.6 mA

Characteristic

  • Screen-grid current [1]

    4 mA

  • Screen-grid current [2]

    1 mA

  • Mutual conductance [1]

    0.7 mA/V

  • Mutual conductance [2]

    0.8 mA/V

  • leak of following valve

    1 MΩ

    PentodeConnection

  • 1) Max. excitation of the stage KC 8 + KDD 1 at Va

    185 V

  • of

    2.2 V

  • ) Max. excitation of the stage KC 3 + KDD 1 at Va

    90 V

  • 135 20,000 2.6 0.5 19 |22Y] 1.1 2 08 | 1.5 0.9

    1.4 V

  • KF 4 used as A.F. amplifier (connected as pentode). Grid leak of following valve

    1 MΩ

    PentodeConnection

  • KT 4 used as A.F amplifier (connected as triode). Grid leak of the following valve

    1 MΩ

    TriodeConnection

  • 1)_Max. excitation of the KL 2 at Va = Vg

    90 V

  • Max. excitation of the KL 4 at Vg Vg

    90 V

  • ?) Max. excitation of the KI. 2 at Va Vgs

    135 V

  • Max. excitation of the KL 4 at Va = Vg

    135 V

  • - gt=0 o

    5 V

  • Py with grid bias as parameter, at Vg

    0 V

  • Saiviiass

    135 V

  • Ml Va-vq2<

    135 V

  • f Vanvg2

    90 V

  • 08g\.§~ meela o [1]

    53 A

  • 08g\.§~ meela o [2]

    135 V

  • o I~ "Va:Vg2

    90 V