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Power - Triode Single (under 10W) ·Triode

958A

Directly heated acorn transmitting triode for RF power amplification and oscillator service through approximately 350 MHz.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
5BD
Socket code
ACORN5
Base pins
5
Nominal heater
1.25 V / 100 mA

Description

The 958A is a directly heated medium-mu acorn transmitting triode intended for RF power amplification and oscillation at frequencies up to 350 MHz. It uses a 1.25 V, 0.10 A coated filament and is rated for Class-C telegraphy service with up to 0.6 W plate dissipation.

Socket description

Acorn 5-pin

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
5BD
Socket code
ACORN5
Base pins
5
Nominal heater voltage
1.25 V
Nominal heater current
100 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

5BD - Terminal pinout

Electrical assignments shared by every tube using this base designation.

No verified pinout is recorded for this base designation.

Section ratings

1 physical section, each with unique specifications.

Section 1

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
10000 Ω
Transconductance
0.0012 S
Amplification factor
12
Max plate voltage
135 V
Max plate dissipation
0.6 W
Max cathode current
7 mA

Published maximum ratings and representative operating characteristics reviewed.

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

1956 RCA Transmitting Tubes

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Maximum operating frequency

    350 MHz

    RF amplifier / oscillator

  • DC grid voltage maximum

    -30 V

    ClassC

  • DC plate current maximum

    7 mA

    ClassC

  • DC grid current maximum

    1 mA

    ClassC

  • Plate input maximum

    0.95 W

    ClassC

  • Typical power output

    0.6 W

    ClassC

Characteristics

  • Grid-to-plate capacitance

    2.5 pF

  • Grid-to-filament capacitance

    0.45 pF

  • Plate-to-filament capacitance

    0.6 pF

Data set 02

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

  • Maximum plate voltage

    135 V

    Published handbook rating

  • Plate voltage

    135 V

    ClassA

  • Control-grid bias

    7.5 V

    ClassA

  • Plate current

    3 mA

    ClassA

Characteristic

  • Plate resistance

    10000 ohm

    Published handbook characteristic

  • Transconductance

    1200 µS

    Published handbook characteristic

  • Amplification factor

    12

    Published handbook characteristic

  • Heater/filament voltage

    1.25 V

    Published heater/filament rating

  • Heater/filament current

    100 mA

    Published heater/filament rating

Data set 03

1960 RCA Industrial and Communications Types

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristic

  • HeaterOrFilamentVoltage

    1.25 V

  • HeaterOrFilamentCurrent

    50 mA

  • MaximumOperatingFrequency

    350 MHz

    Approximate/useful limit

  • Application

    Transmitter RF amplifier and oscillator