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Voltage Pentode or Tetrode (under 100V) ·Heptode

DK91

Directly heated battery heptode for oscillator-mixer frequency conversion in portable superheterodyne receivers. Its 1.4 V, 50 mA filament provides useful receiver conversion performance with very low filament power consumption.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
B7G
Socket code
B7G
Base pins
7
Nominal heater
1.4 V / 50 mA

Description

Miniature heptode frequency changer for battery-operated receivers, suitable for AVC and including an oscillator function.

Socket description

Miniature 7-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
B7G
Socket code
B7G
Base pins
7
Nominal heater voltage
1.4 V
Nominal heater current
50 mA
Parallel heater voltage
1.4 V
Parallel heater current
50 mA
Series capable
Yes

B7G - 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

Heptode

X-ray radiationInterelectrode capacitances
Plate resistance
800000 Ω
Transconductance
0.0014 S
Max plate voltage
90 V
Max screen voltage
67.5 V
Max plate dissipation
0.15 W
Max screen dissipation
0.25 W
Max cathode current
5.5 mA

Heptode frequency changer for battery receivers.

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

1951 Mullard Valve and Service Manual

Published operating points and test conditions from this source.

SECTION 1

Heptode

Other

  • Plate Voltage

    90 V

  • Screen Voltage

    67.5 V

  • Plate Current

    1.6 mA

Characteristic

  • Conversion Conductance

    300 µS

  • Plate Resistance

    600000 ohm

  • Oscillator Transconductance

    1400 µS

Data set 02

1961 Ferranti Technical Handbook

Published operating points and test conditions from this source.

SECTION 1

Heptode

Application

  • Application

    Frequency changer / oscillator-mixer

Other

  • Maximum useful frequency

    20 MHz

Data set 03

1963 Mullard

Published operating points and test conditions from this source.

SECTION 1

Heptode

Characteristics

  • Filament Voltage

    1.4 V

    DCOnly

  • Filament Current

    50 mA

    DCOnly

  • Plate Resistance

    600000 ohm

    Representative

  • Conversion Transconductance

    300 uS

    Representative

  • Oscillator Transconductance

    1400 uS

    OscillatorSection

Other

  • Plate Voltage

    90 V

    FrequencyChanger

  • Screen Voltage

    67.5 V

    FrequencyChanger

  • Plate Current

    1.6 mA

    FrequencyChanger

  • Screen Current

    3.2 mA

    FrequencyChanger

  • Grid Current

    250 uA

    FrequencyChanger

  • Total Cathode Current

    5 mA

    FrequencyChanger

  • Maximum Plate Voltage

    90 V

  • Maximum Screen Voltage

    67.5 V

  • Maximum Cathode Current

    5.5 mA

Data set 04

1963 Philips Electron Tubes Handbook V1

Published operating points and test conditions from this source.

SECTION 1

Heptode

Capacitance

  • Plate capacitance

    7.5 pF

  • Grid-3 capacitance

    7 pF

  • Plate-to-grid-3 capacitance

    - to 0.4 pF

Other

  • Plate voltage

    67.5 V

    FrequencyChanger

  • Screen voltage

    67.5 V

    FrequencyChanger

  • Plate current

    1.6 mA

    FrequencyChanger

  • Screen current

    3.2 mA

    FrequencyChanger

Characteristic

  • Plate resistance

    0.6 Mohm

Data set 05

1967 Mullard Receiving Tubes for Maintenance

Published operating points and test conditions from this source.

SECTION 1

Heptode

Capacitance

  • All-Grid Input Capacitance

    7 pF

    PublishedCapacitance

  • Plate-to-All Capacitance

    7.5 pF

    PublishedCapacitance

  • Control-Grid-to-All Capacitance

    3.8 pF

    PublishedCapacitance

  • Oscillator-Grid-to-Plate Capacitance

    <0.4 pF

    PublishedCapacitance

Other

  • Plate Voltage

    90 V

    FrequencyChanger;90VPoint

  • Screen/Oscillator Grid Voltage

    67.5 V

    FrequencyChanger;90VPoint

  • Plate Resistance

    600 kohm

    FrequencyChanger;90VPoint

  • Conversion Conductance

    300 uS

    FrequencyChanger;90VPoint

  • Plate Current

    1.6 mA

    FrequencyChanger;90VPoint

  • Screen/Oscillator Grid Current

    3.2 mA

    FrequencyChanger;90VPoint

  • Oscillator Grid Current

    250 uA

    FrequencyChanger;90VPoint

  • Cathode Current

    5 mA

    FrequencyChanger;90VPoint

  • Oscillator Transconductance

    1400 uS

    FrequencyChanger;90VPoint

  • Plate Voltage

    90 V

    PublishedLimits

  • Grid 2+4 Supply Voltage

    90 V

    PublishedLimits

  • Grid 2+4 Voltage

    67.5 V

    PublishedLimits

  • Cathode Current

    5.5 mA

    PublishedLimits

Data set 06

1999 Philips 0-D

Published operating points and test conditions from this source.

SECTION 1

Heptode

Other

  • Conversion transconductance at 45 V

    235 µS

    FrequencyConverter

  • Conversion transconductance at 67.5 V

    280 µS

    FrequencyConverter