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Voltage - Dual Triode (similar) ·Triode-Triode

B719

Marconi RF double triode designed for FM receiver front ends, combining RF amplifier and mixer service around the FM broadcast frequency range.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
-
Socket code
B9A
Base pins
9
Nominal heater
6.3 V / 435 mA

Description

The Marconi B719 is a rf double triode for fm receiver amplifier and mixer service.

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
6.3 V
Nominal heater current
435 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

2 physical sections, each with unique specifications.

Section 1

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
9700 Ω
Transconductance
0.006 S
Amplification factor
60
Max plate voltage
300 V
Max plate dissipation
2.5 W

Representative section for two equal triode systems.

Section 2

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
9700 Ω
Transconductance
0.006 S
Amplification factor
60
Max plate voltage
300 V
Max plate dissipation
2.5 W

Second physical triode restored under current one-row-per-physical-section policy.

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

Triode

Other

  • Heater voltage

    6.3 V

  • Heater current

    435 mA

  • Maximum plate voltage

    300 V

  • Maximum plate dissipation per section

    2.5 W

  • Typical RF test frequency

    100 MHz

Characteristic

  • Amplification factor

    60

  • Transconductance

    6000 uS

  • Plate resistance

    9700 ohm

Capacitance

  • Grid-plate capacitance

    1.5 pF

  • Grid-cathode capacitance

    0.18 pF

  • Plate-cathode capacitance

    0.04 pF

Application

  • FM receiver application

    RF amplifier and mixer