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Voltage - Triode (with diode, heptode or hexode) ·Hexode-Triode

ECH42

Triode-heptode oscillator-mixer for superheterodyne receivers. The separate triode provides local oscillation while the heptode performs frequency conversion with useful gain and oscillator-to-input isolation.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
-
Socket code
B8A
Base pins
8
Nominal heater
6.3 V / 230 mA

Description

Triode-hexode for oscillator and frequency-converter service in radio receivers.

Socket description

Rimlock 8-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
B8A
Base pins
8
Nominal heater voltage
6.3 V
Nominal heater current
230 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

2 physical sections, each with unique specifications.

Section 1

Hexode

X-ray radiationInterelectrode capacitances
Max plate voltage
250 V
Max screen voltage
125 V
Max plate dissipation
1.5 W
Max screen dissipation
0.3 W
Max cathode current
7 mA

Hexode section; values semantically promoted from published characteristics/maximum-ratings tables where present.

Section 2

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
400000 Ω
Transconductance
0.0021 S
Max plate voltage
175 V
Max plate dissipation
0.8 W
Max cathode current
6 mA

Triode section; values semantically promoted from published characteristics/maximum-ratings tables where present.

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

Hexode

Characteristics

  • Cutoff characteristic

    Variable-mu

Application

  • Service

    Frequency changer / mixer

SECTION 2

Triode

Application

  • Service

    Local oscillator

Data set 02

1953 La Radiotechnique

Published operating points and test conditions from this source.

SECTION 1

Hexode

Other

  • Haute tension . . . . . . Vh

    250 V

    Hexode

  • Resistance du circuit dela grille3. Rg,4,r

    22 Kohm

    Hexode

  • Courant de la grille 3(1) . . . Ig4+7

    350 uA

    Hexode

  • Tension de la grille 1 . . . . Veg,

    2 V

    Hexode

  • Tension des grilles 2et4 . . . Vg,4,

    8 V

    Hexode

  • Courant anodique . . . . . Tay

    3 mA

    Hexode

  • Courant des grilles 2et4 . . . 18544

    3 mA

    Hexode

  • Resistance interme . . . - - P > 1 MQ

    1 Mohm

    Hexode

  • (1) Si on choisit Rg, 4 7

    47 Kohm

    Hexode

  • Tension des grilles 2et4 . . . Vg,,,

    125 V

    Hexode

  • Puissance dissipee surles grilles2et4 Pg,,,

    0.3 W

    Hexode

  • Courant cathodique._ . . . . k

    7 mA

    Hexode

SECTION 2

Triode

Characteristic

  • Indireet (cathode isolee du filament) . . Ê V£t

    63 V

    Triode

  • Alimentation du filament en parallele. If

    230 mA

    Triode

Other

  • Tension de l’anode . . . . . Var

    100 V

    Triode

  • Tension de la grille . . . . . Vgs4yq

    -2 V

    Triode

  • Courant anodique . . . . . Iar

    55 mA

    Triode

  • Resistance interne . . . . < P

    400 ohm

    Triode

  • Pente. . . . . . + . . S

    2.1 mA/V

    Triode

  • Tension de l’anode . . . . . Var

    175 V

    Triode

  • Puissance dissipee sur l’anode . . Pay s

    8 W

    Triode

  • Resistance du circuit de la grille. Rg,

    3 Mohm

    Triode

  • Resistanceentrefilamentet cathode Rkf

    20 Kohm

    Triode

  • Tension entre filament et cathode. Vkf

    50 V

    Triode

  • pav MQ 27 KQ

    27 Kohm

    Triode

  • vat

    -2 V

    Triode

  • 0 VaT

    100 V

    Triode

Capacitance

  • Capacite de la grille l hexode . . Cg,

    44 pF

    Triode

  • Capacite de l’anode hexode . . Can

    9 pF

    Triode

  • Capacite de la grille triode

    7.6 pF

    Triode

  • Capacite de l’anode triode . . . Car

    45 pF

    Triode

  • Capacite d’entree hexode . . . Cg,

    52 pF

    Triode

Data set 03

1958 Brimar Radio Valve No 7

Published operating points and test conditions from this source.

SECTION 1

Hexode

Characteristic

  • Conversion Conductance

    750 uS

    FrequencyChanger

SECTION 2

Triode

Characteristic

  • Heater Voltage

    6.3 V

  • Heater Current

    230 mA

Data set 04

1968 Mazda Belvu

Published operating points and test conditions from this source.

SECTION 1

Hexode

Characteristics

  • Heater voltage

    6.3 V

    Published nominal value

  • Heater current

    230 mA

    Published nominal value

Other

  • Maximum plate dissipation

    1.5 W

    Published maximum rating

  • Application

    Oscillator-frequency converter

    Printed source application

SECTION 2

Triode

Characteristics

  • Heater voltage

    6.3 V

    Published nominal value

  • Heater current

    230 mA

    Published nominal value

Other

  • Maximum plate dissipation

    0.8 W

    Published maximum rating