4KN8

Frame-grid twin triode designed for VHF cascode amplifier service in television tuners, combining two high-frequency triode sections for sensitive RF front-end amplification.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: -
Socket code: B9A
Base pins: 9
Nominal heater: 4.2 V / 600 mA

Description

Frame-grid twin triode for VHF cascode amplifier service in television tuners.

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: 4.2 V
Nominal heater current: 600 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: 2800 Ω
Transconductance: 0.016 S
Amplification factor: 45
Max plate voltage: 290 V
Max plate dissipation: 2.2 W
Max cathode current: 22 mA

Repeated identical physical sections represented by one populated row.

Section 2

Triode

X-ray radiationInterelectrode capacitances

Plate resistance: 2800 Ω
Transconductance: 0.016 S
Amplification factor: 45
Max plate voltage: 290 V
Max plate dissipation: 2.2 W
Max cathode current: 22 mA

Second physical triode section; electrically identical twin 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

1963 Hitachi

Published operating points and test conditions from this source.

SECTION 1

Triode

Capacitance

Interelectrode capacitances published
1
See source table

Characteristic

Heater Warm-up Time
11 s

Other

Cascode Plate Supply Voltage
220 V
CascodeAmplifier