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Voltage Pentode - Remote Cutoff (single) ·Pentode

14A7

Variable-mu lock-in pentode for gain-controlled RF/IF voltage amplification in AC/DC receivers.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
8V
Socket code
LOCTAL8
Base pins
8
Nominal heater
12.6 V / 150 mA

Description

The 14A7/12B7 is a lock-in pentode voltage amplifier designed for radio-frequency and intermediate-frequency service in AC/DC receivers.

Socket description

Loctal 8-contact base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
8V
Socket code
LOCTAL8
Base pins
8
Nominal heater voltage
12.6 V
Nominal heater current
150 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

8V - Terminal pinout

Electrical assignments shared by every tube using this base designation.

TerminalSectionConnectionEvidence
PIN1H—H — Heater

EIA source transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 8V

PIN2PAP — Plate (Anode)

EIA source transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 8V

PIN3G2AG2 — Screen Grid

EIA source transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 8V

PIN4G3AG3 — Suppressor Grid

EIA source transcription; manufacturer confirmation pending

Unverified

EIA Base Connections, printed page 129, 8V

PIN5ISAIS — Internal Screen

EIA chart transcription; manufacturer verification pending

Unverified

EIA Base Connections, printed page 129, 8V

PIN6G1AG1 — Control Grid

EIA chart transcription; manufacturer verification pending

Unverified

EIA Base Connections, printed page 129, 8V

PIN7KAK — Cathode

EIA chart transcription; manufacturer verification pending

Unverified

EIA Base Connections, printed page 129, 8V

PIN8H—H — Heater

EIA chart transcription; manufacturer verification pending

Unverified

EIA Base Connections, printed page 129, 8V

Section ratings

1 physical section, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances
Plate resistance
120000 Ω
Transconductance
0.00235 S
Max plate voltage
300 V
Max screen voltage
150 V
Max plate dissipation
4 W
Max screen dissipation
0.4 W

Published maximum ratings, operating characteristics, and continuation data reviewed.

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

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Maximum plate voltage

    300 V

    Published handbook rating

  • Maximum screen voltage

    125 V

    Published handbook rating

  • Plate voltage

    250 V

    ClassA

  • Screen voltage

    100 V

    ClassA

  • Control-grid bias

    3 V

    ClassA

  • Plate current

    9.2 mA

    ClassA

  • Screen current

    2.6 mA

    ClassA

Characteristic

  • Plate resistance

    800000 ohm

    Published handbook characteristic

  • Transconductance

    2000 µS

    Published handbook characteristic

  • Heater voltage

    12.6 V

    Published heater rating

  • Heater current

    150 mA

    Published heater rating

Data set 02

1966 Tung Sol Electronic Tubes 3 of 4

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Typical plate voltage

    100 V

    ClassA

  • Typical screen voltage

    100 V

    ClassA

  • Typical plate current

    13 mA

    ClassA

  • Typical screen current

    4 mA

    ClassA

  • Maximum plate voltage

    300 V

    PromotedValue

  • Maximum screen voltage

    125 V

    PromotedValue

  • Maximum plate dissipation

    4 W

    PromotedValue

  • Maximum screen dissipation

    0.4 W

    PromotedValue

Capacitance

  • Grid-to-plate capacitance

    0.003 pF

  • Input capacitance

    6 pF

  • Output capacitance

    7 pF

Characteristics

  • Plate resistance

    120000 ohm

    PromotedValue

  • Transconductance

    0.00235 A/V

    PromotedValue