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Power - Triode ·Triode

RS242

Directly heated Telefunken-derived transmitter and audio power triode suitable for Class A operation. Rated for approximately 17 W plate dissipation and 500 V plate voltage, with moderate gain and relatively low plate resistance.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
1
Base
-
Socket code
-
Base pins
-
Nominal heater
4 V / 900 mA

Description

Directly heated Telefunken-derived RS242 transmitter/audio triode. The supplied Emission Labs sheet was read for filament data, maximum ratings, representative operating points, gm/rp/mu, output conditions, capacitances, and rectifier filter conditions as applicable.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
-
Base pins
-
Nominal heater voltage
4 V
Nominal heater current
900 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

1 physical section, each with unique specifications.

Section 1

Triode

X-ray radiationInterelectrode capacitances
Plate resistance
4700 Ω
Transconductance
0.0046 S
Amplification factor
17
Max plate voltage
500 V
Max plate dissipation
17 W
Max cathode current
70 mA

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

2026 Emission Labs

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristics

  • Filament voltage

    4 V

  • Filament current

    900 mA

  • Plate resistance

    4700 ohm

    ClassA

  • Amplification factor

    17

    ClassA

  • Transconductance

    4600 uS

    ClassA

Other

  • Plate voltage

    400 V

    ClassA

  • Plate current

    30 mA

    ClassA

  • Grid voltage

    -10.9 V

    ClassA

  • Driver output voltage

    60 V RMS

    PlateVoltage=350V;PlateCurrent=20mA

  • Circuit gain

    16.3

    DriverService