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Voltage Pentode - Remote Cutoff (single) ·Pentode

AF3

Indirectly heated variable-mu high-frequency pentode designed for gain-controlled RF and IF amplifier service. Its extended-control characteristic provides smooth automatic gain regulation in receiver signal stages.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
P30
Socket code
P8A
Base pins
8
Nominal heater
4 V / 650 mA

Description

Indirectly heated variable-mu high-frequency pentode for gain-controlled RF and IF amplifier service.

Socket description

European 8-pin side-contact base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
P30
Socket code
P8A
Base pins
8
Nominal heater voltage
4 V
Nominal heater current
650 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

P30 - 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
1200000 Ω
Transconductance
0.0018 S
Max plate voltage
250 V
Max screen voltage
125 V
Max plate dissipation
2 W
Max screen dissipation
0.4 W
Max cathode current
15 mA

Remote-cutoff RF pentode; promoted nominal characteristic set uses Va=200/250 V family data and Vg2=100 V.

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

    250 V

  • Screen voltage

    100 V

  • Screen current

    2.6 mA

Characteristics

  • Transconductance

    1800 µS

  • Remote-cutoff grid bias

    -53 V

  • Grid-anode capacitance

    0.003 pF

Data set 02

1953 RFT Rundfunk Technik

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristics

  • Heater or filament voltage

    4 V

    Published nominal value

  • Heater or filament current

    650 mA

    Published nominal value

  • Transconductance

    1800 µS

    Published operating characteristic

Data set 03

1959 Telefunken

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

  • HeaterOrFilamentVoltage

    4 V

  • HeaterOrFilamentCurrent

    1 A

  • CutoffCharacteristic

    Variable mu

  • MaximumControlVoltage

    -35 V

    GainControl

Data set 04

195X Tunsgram

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Typical screen voltage

    100 V

  • Typical plate current

    8 mA

  • Maximum no-current anode voltage

    550 V

  • Maximum screen no-current voltage

    400 V

  • Maximum heater-cathode voltage

    80 V

Characteristic

  • Maximum transconductance

    0.0028 A/V

Data set 05

1999 Philips 0-D

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristics

  • Heater voltage

    4 V

  • Heater current

    650 mA

  • Plate voltage

    250 V

  • Screen/auxiliary voltage

    100 V

  • Plate current

    8 mA

  • Screen/auxiliary current

    2.6 mA

  • Transconductance

    1800 uS

  • Plate resistance

    1200000 ohm

Capacitance

  • Input capacitance

    6.4 pF

  • Output capacitance

    7.6 pF

  • Plate-grid capacitance maximum

    0.003 pF