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Voltage Triode Pentode ·Pentode-Triode

8445

Reliable mobile-radio combination tube containing a medium-mu triode and sharp-cutoff high-frequency pentode with separate cathodes.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
-
Socket code
B9A
Base pins
9
Nominal heater
13.5 V / 220 mA

Description

Reliable mobile-radio combination tube containing a medium-mu triode and a sharp-cutoff high-frequency pentode with separate cathodes.

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
-
Socket code
B9A
Base pins
9
Nominal heater voltage
13.5 V
Nominal heater current
220 mA
Parallel heater voltage
6.75 V
Parallel heater current
440 mA
Series capable
Yes

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

Triode

X-ray radiationInterelectrode capacitances
Transconductance
0.007 S
Amplification factor
43
Max plate voltage
330 V
Max plate dissipation
2 W

Medium-mu triode section.

Section 2

Pentode

X-ray radiationInterelectrode capacitances
Plate resistance
400000 Ω
Transconductance
0.0062 S
Max plate voltage
330 V
Max screen voltage
200 V
Max plate dissipation
1.7 W
Max screen dissipation
0.5 W

Sharp-cutoff pentode section.

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

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Heater voltage

    13.5 V

    Nominal

  • Heater current

    220 mA

    Nominal

SECTION 2

Pentode

Other

  • Heater voltage

    13.5 V

    Nominal

  • Heater current

    220 mA

    Nominal

Data set 02

1966 Tung Sol Electronic Tubes 4 of 4

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Plate voltage

    100 V

    Triode

  • Grid voltage

    -1 V

    Triode

  • Plate current

    12.5 mA

    Triode

Characteristic

  • Transconductance

    7000 uS

    Triode

  • Amplification factor

    43

    Triode

Capacitance

  • Triode-grid to pentode-plate capacitance

    0.02 pF

    Coupling

  • Pentode-grid to triode-plate capacitance

    0.16 pF

    Coupling

  • Pentode-plate to triode-plate capacitance

    0.07 pF

    Coupling

SECTION 2

Pentode

Other

  • Heater voltage

    6.75 V

  • Heater current

    440 mA

  • Heater voltage limits minimum

    6 V

  • Heater voltage limits maximum

    7.5 V

  • Maximum heater-cathode voltage

    200 V

  • Plate voltage

    170 V

    Pentode

  • Screen voltage

    170 V

    Pentode

  • Grid voltage

    -2 V

    Pentode

  • Plate current

    10 mA

    Pentode

  • Screen current

    2.5 mA

    Pentode

Characteristic

  • Transconductance

    6200 uS

    Pentode

  • Plate resistance

    400000 ohm

    Pentode