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Voltage Pentode - Remote Cutoff (single) ·Pentode

7A7LM

Single-ended metal triple-grid super-control variable-mu amplifier pentode. Its extended-control characteristic is designed for smooth gain regulation in receiver signal stages.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
B8G
Base pins
8
Nominal heater
6.3 V / 300 mA

Description

Single-ended metal triple-grid super-control variable-mu amplifier pentode.

Socket description

Loctal 8-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
B8G
Base pins
8
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
800000 Ω
Transconductance
0.002 S
Max plate voltage
250 V
Max screen voltage
100 V

Published ratings and characteristics promoted from the approved RCA 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

1940 RCA

Published operating points and test conditions from this source.

SECTION 1

Pentode

Application

  • Application

    VariableMuAmplifier text