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Voltage Radio Detector Converter ·Diode-Pentode

UAF42

Series-heater diode variable-mu pentode combining receiver detection with controlled RF, IF, or audio amplification. The pentode provides broad gain control while the diode supplies independent detection.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
-
Socket code
B8A
Base pins
8
Nominal heater
12.6 V / 100 mA

Description

Detector diode and variable-mu pentode for radio-frequency or intermediate-frequency amplification. The supplied French datasheet was translated to English for descriptive output.

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
12.6 V
Nominal heater current
100 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

Diode

X-ray radiationInterelectrode capacitances
Max plate voltage
200 V
Max cathode current
0.8 mA
Rectifier peak inverse voltage
350 V
Rectifier peak forward current
5 mA
Rectifier max heater-cathode voltage
150 V

Published ratings and characteristics promoted from the approved source.

Section 2

Pentode

X-ray radiationInterelectrode capacitances
Plate resistance
900000 Ω
Transconductance
0.002 S
Max plate voltage
170 V
Max screen voltage
85 V
Max plate dissipation
2 W
Max screen dissipation
0.3 W
Max cathode current
10 mA

Published ratings and characteristics promoted from the approved source.

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 2

Pentode

Other

  • Pentode Plate Voltage

    120 V

    PentodeSection

  • Pentode Plate Current

    3.8 mA

    PentodeSection

Characteristic

  • Pentode Transconductance

    1500 µS

    PentodeSection

Data set 02

1953 La Radiotechnique

Published operating points and test conditions from this source.

SECTION 1

Diode

Other

  • HeaterVoltageNominal

    12.6 V

    Nominal

  • HeaterCurrentNominal

    100 mA

    Nominal

  • Maximum Plate Voltage

    200 V

SECTION 2

Pentode

Other

  • HeaterVoltageNominal

    12.6 V

    Nominal

  • HeaterCurrentNominal

    100 mA

    Nominal

  • Maximum Plate Voltage

    170 V

  • Maximum Screen Voltage

    85 V

Characteristic

  • Transconductance

    2000 µS

    Typical

  • Amplification Factor

    1800

    Typical

  • Plate Resistance

    900000 ohm

    Typical

Data set 03

1957 Philips Receiving and Amplifying Tubes

Published operating points and test conditions from this source.

SECTION 2

Pentode

Characteristics

  • Cutoff characteristic

    Variable-mu

Application

  • Application

    RF / IF / AF amplifier

Data set 04

1963 Philips Electron Tubes Handbook V1

Published operating points and test conditions from this source.

SECTION 1

Diode

Other

  • Maximum inverse voltage

    350 V

  • Maximum average diode current

    0.8 mA

  • Maximum peak diode current

    5 mA

SECTION 2

Pentode

Other

  • Plate voltage

    170 V

    RF/IF amplifier

  • Screen voltage

    85 V

    RF/IF amplifier

  • Plate current

    5 mA

    RF/IF amplifier

  • Screen current

    1.5 mA

    RF/IF amplifier

  • Maximum plate voltage

    250 V

  • Maximum screen voltage

    250 V

  • Maximum plate dissipation

    2 W

Characteristic

  • Transconductance

    2000 uS

    RF/IF amplifier

  • Plate resistance

    0.9 Mohm

    RF/IF amplifier

Data set 05

1967 Mullard Receiving Tubes for Maintenance

Published operating points and test conditions from this source.

SECTION 1

Diode

Other

  • Single diode R.F. pentode with

    100 mA

    Published in approved UAF42.pdf target datasheet; Section1

  • gm 1.7 20

    2 mA

    Published in approved UAF42.pdf target datasheet; Section1

  • Vga(la<

    2.5 mA

    Published in approved UAF42.pdf target datasheet; Section1

  • Vga (1. =

    5 mA

    Published in approved UAF42.pdf target datasheet; Section1

  • I k max

    10 mA

    Published in approved UAF42.pdf target datasheet; Section1

  • lad max

    0.8 mA

    Published in approved UAF42.pdf target datasheet; Section1

SECTION 2

Pentode

Other

  • Single diode R.F. pentode with

    100 mA

    Published in approved UAF42.pdf target datasheet; Section2

  • gm 1.7 20

    2 mA

    Published in approved UAF42.pdf target datasheet; Section2

  • Vga(la<

    2.5 mA

    Published in approved UAF42.pdf target datasheet; Section2

  • Vga (1. =

    5 mA

    Published in approved UAF42.pdf target datasheet; Section2

  • I k max

    10 mA

    Published in approved UAF42.pdf target datasheet; Section2

  • lad max

    0.8 mA

    Published in approved UAF42.pdf target datasheet; Section2

Data set 06

1968 Mazda Belvu

Published operating points and test conditions from this source.

SECTION 1

Diode

Other

  • Tension filament

    12.6 V

  • Courant filament

    100 mA

  • Capacité grille n°1/ anode …… … Cg/a

    2 mpF

  • Capacité grille n° 1/filament ……s Cg,/f

    0.05 pF

  • Capacité anode/ cathode filament …… Ca/ kf

    3.3 pF

  • Capacité anode/filament ……c Ca/f

    0.02 pF

  • Capacité anode Diode/ grille n° 1 .…….….…..…..….….….…… CaD/ #

    1.5 mpF

  • Capacité anode Diode/ anode Pentode CaD/aP

    150 mpF

  • Tension d'anode à courant nul ………..…..…...serereneens

    550 V

  • Tension d'anode ……s … V

    250 V

  • Tension de grille n°2 à courant nul

    550 V

  • Tension de grille no 2 pour Ia < 2,5 MA … ….……urercrsccar- Ve,

    250 V

  • pour Ia =5 mA

    125 V

  • Dissipation de grille n°e2

    0.3 W

  • Courant de cathode

    10 mA

  • Résistance du circuit de grille n° 1 .........…..…………cseuss

    3 MΩ

  • Tension entre filament et cathode

    150 V

  • Tension inverse de crête d'anode ……s Vaicr

    350 V

  • Courant d'anode

    0.8 mA

  • Courant de crête d'anode

    5 mA

  • Tension entre filäment et cathode ……s

    150 V

Capacitance

  • Capacité d'entrée …..….....……ecerseeneosenenseennenn Ce

    4.1 pF

  • Capacité de sortie …… … Cs

    5.2 pF

Characteristic

  • Tension d'alimentation ……s VN - 100 170

    200 V

  • Tension d'anode …..….…..…..…...….crrrereeens Va 100 170

    200 V

  • Résistance de cathode …… Rk 310 310

    310 Ω

  • Tension de grille n° 1 …..…...……risercerses Ves -1,2 -2

    -2 V

  • Tension dé grille n° 2 ... \ 50 85

    85 V

  • Courant d'Anode ……s 2,8 5

    5 mA

  • Pente …… 1,7 2

    2 mA

  • Résistance interne … 0,85 0,9

    1 MΩ

  • Résistance équivalente de bruit …… RBeq 5,8 T,5

    7.5 kΩ

  • de 1/ 100 de laà valeur nominale …… Ve, -16 -28

    -34 V

Data set 07

1999 Philips E-Z

Published operating points and test conditions from this source.

SECTION 2

Pentode

Characteristic

  • Input capacitance

    4 pF

    Pentode

  • Output capacitance

    6.5 pF

    Pentode

Other

  • Anode-grid capacitance

    0.002 pF

    Pentode

  • Typical transconductance

    1800 µS

    RFIFAmplifier