396A

Medium-mu twin triode with separate cathodes for amplifier, mixer, oscillator and multivibrator service at frequencies extending into UHF, combining compact construction with useful high-frequency characteristics.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: E9-1
Socket code: B9A
Base pins: 9
Nominal heater: 6.3 V / 300 mA

Description

Twin triode with separate cathodes for amplifier, mixer, oscillator and multivibrator service, usable to about 800 MHz.

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: E9-1
Socket code: B9A
Base pins: 9
Nominal heater voltage: 6.3 V
Nominal heater current: 300 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

E9-1 - 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: 6400 Ω
Transconductance: 0.0055 S
Amplification factor: 35
Max plate voltage: 300 V
Max plate dissipation: 1.5 W
Max grid dissipation: 0.1 W

Two physically identical triode sections with separate cathodes; one representative TUBE_SECTION row is used per the repeated-identical-section rule. Promoted values apply to each section.

Section 2

Triode

X-ray radiationInterelectrode capacitances

Plate resistance: 6400 Ω
Transconductance: 0.0055 S
Amplification factor: 35
Max plate voltage: 300 V
Max plate dissipation: 1.5 W
Max grid dissipation: 0.1 W

Second identical physical triode section with separate cathode; added to align rows with SectionCount.

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

1965 Ericsson Longlife

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Plate supply voltage
150 V
ClassA;EachSection
Cathode bias resistor
240 Ohm
ClassA;EachSection
Plate current
8.2 mA
ClassA;EachSection
Plate supply voltage
300 V
ClassAB;PushPull;TwoTubes
Load impedance plate-to-plate
40000 Ohm
ClassAB;PushPull;TwoTubes
Maximum signal power output
1 W
ClassAB;PushPull;TwoTubes
Total harmonic distortion
10 %
ClassAB;PushPull;TwoTubes
Heater current maximum
320 mA
Plate current maximum
10 mA
EachSection
Transconductance maximum
6600 uS
EachSection

Characteristics

Transconductance
5500 uS
ClassA;EachSection
Amplification factor
35 ratio
ClassA;EachSection
Plate resistance
6400 Ohm
ClassA;EachSection
Equivalent noise resistance
500 Ohm
EachSection
Input conductance at 100 MHz
130 uS
EachSection

Data set 02

2026 Western Electric 300s

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

GridPlateCapacitance
1.3 pF
Per section; without external shield
Input Capacitance
2.2 pF
Per section; without external shield
Output Capacitance
1 pF
Per section; without external shield
Plate To Plate Capacitance
0.04 pF
Typical; without external shield
MaximumPlateToPlateCapacitance
0.11 pF
Without external shield
Maximum Plate Current
16 mA
Each section
Maximum Heater Cathode Voltage
90 V

Characteristic

Plate Current
8.2 mA
ClassA; EachSection; Plate=150 V; Grid=-2 V
Transconductance
5500 uS
ClassA; EachSection; Plate=150 V
Amplification Factor
35
ClassA; EachSection