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Power - Pentode (NOT beam) ·Pentode-Triode

LN309

Triode/power-pentode combination for compact audio amplifiers, integrating voltage gain and loudspeaker output.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
B9A
Socket code
B9A
Base pins
9
Nominal heater
12.6 V / 300 mA

Description

Combined triode-pentode with audio-power pentode and voltage-amplifier triode systems.

Socket description

Small-button Noval 9-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
B9A
Socket code
B9A
Base pins
9
Nominal heater voltage
12.6 V
Nominal heater current
300 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

B9A - 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

Pentode

X-ray radiationInterelectrode capacitances
Plate resistance
45000 Ω
Transconductance
0.0047 S
Max plate voltage
250 V
Max screen voltage
250 V
Max plate dissipation
5.4 W
Max screen dissipation
1.2 W

Pentode system.

Section 2

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
7700 Ω
Transconductance
0.0022 S
Amplification factor
17
Max plate voltage
250 V
Max plate dissipation
3.5 W

Triode system.

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

1955 Marconi

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • Pentode Grid-Anode Capacitance

    0.05 pF

  • Pentode Grid-TriodeGrid Capacitance

    0.03 pF

  • Pentode Grid-All Capacitance

    6 pF

  • Pentode Anode-TriodeGrid Capacitance

    0.2 pF

  • Pentode Anode-TriodeCathode Capacitance

    0.3 pF

  • Triode Anode-PentodeAnode Capacitance

    1.9 pF

  • Triode Anode-PentodeGrid Capacitance

    0.12 pF

  • Triode Anode-All Capacitance

    6.9 pF

  • Pentode Class-A Output Power

    2.1 W

    ClassA

  • Pentode Push-Pull Output Power

    5.4 W

    ClassAB;PushPull;TwoTubes

  • Cascade Amplifier Output Power

    2.1 W

    TriodeDrivesPentode