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Voltage Pentode - Sharp Cutoff (single) ·Pentode

EF94

Indirectly heated fixed-slope pentode designed for RF voltage amplification. Its abrupt transfer characteristic provides fixed high-frequency gain rather than the variable-mu behavior used for automatic gain control.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
B7G
Base pins
7
Nominal heater
6.3 V / 300 mA

Description

Indirectly heated fixed-slope pentode for RF voltage amplification.

Socket description

Miniature 7-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
B7G
Base pins
7
Nominal heater voltage
6.3 V
Nominal heater current
300 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
1500000 Ω
Transconductance
0.0044 S
Max plate voltage
250 V
Max screen voltage
150 V
Max plate dissipation
3 W
Max screen dissipation
0.65 W

Published ratings/characteristics promoted from source tables.

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

1968 Mazda Belvu

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Heater voltage = ...…eccrerseersermescenserçeesesssesesesousess VË

    6.3 V

  • Heater current …If

    300 mA

  • Tension d'ANOËE L.………scosriesencenssensescenceoncessensesssesraerenaveenees VO

    300 V

  • Screen-grid voltage … Ve

    150 V

  • Screen-grid voltage àcourant nul ascssssssassseeeserssecen V 82 DL

    300 V

  • Plate dissipation … asnoncrsosesssccoreausnerersenveemernsenseccsecnren PB

    3 W

  • Screen-grid dissipation arsccsseressertenenaene se ssssecace en se sess se E 22

    0.65 W

  • valeur de polarisation négative … … -VEg

    50 V

  • valeur de polarisation positive … … Ve

    0 V

  • Tension entre filament et cathod@ ……s VIE

    180 V

  • Plate voltage … sevsestensessesenseneesenemenventencse | V 100 | 250

    250 V

  • Screen-grid voltage … Vg, 100 | 125 |j

    150 V

  • Plate resistance (approx.) p 0,5 | 1,5

    1 MΩ

  • Transconductance ……c .S 3,9| 4,5

    5.2 mA/V

  • d'anode de

    10 uA

  • 4,2 |-5,5

    -6.5 V

  • Plate current …… A 5,2 | 7,6

    10.8 mA

  • Courant de grille n° Z.…veseremensesenmnnnün 2,1 31

    4.3 mA

  • se orenensoense | V O

    250 V

  • Tension positive de gr1lle n° 1

    0 V

  • Plate dissipation … “

    3.2 W

  • Tension entre f11ament et cathode

    180 V

  • Tension d'ANOdE ……c seenmereenenentennnennnsnnnnnmnnnemnnnns V

    250 V

  • Résistance dé cathode … … Rk

    330 Ω

  • Plate resistance …… … p

    7.5 kΩ

  • Transconductance ……s …oS

    4.8 mA/V

  • se se se ucc L

    12.2 mA

Characteristic

  • Capacitance d'Entré@ … …srenseeenenenesnmennätîssss CC

    5.5 pF

    InterelectrodeCapacitance

  • Capacitance d€ SOIÈLE .… …cessenssseencassrsssncancansemenens CS

    5 pF

    InterelectrodeCapacitance

  • Capacitance grille n° 1/ AN0d€ ………rrreereeereessene CB,/à

    3.5 pF

    InterelectrodeCapacitance

  • Capacitance d'Entrée …..……meemeeiassenenennnnnnnÜNCe

    3.1 pF

    InterelectrodeCapacitance

  • sossvens CS

    1.7 pF

    InterelectrodeCapacitance

  • Capacitance grille n° 1/ AN0d€ ………………ersecerrererres CB1/A

    2.5 pF

    InterelectrodeCapacitance