RK33

Twin triode designed for RF power-amplifier and oscillator service, with two similar systems and published Class-C output capability to approximately 60 MHz.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: -
Socket code: MEDIUM7
Base pins: 7
Nominal heater: 6.3 V / 600 mA

Description

Twin triode RF power amplifier and oscillator with two similar triode systems.

Socket description

Medium 7-contact transmitting-tube base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: MEDIUM7
Base pins: 7
Nominal heater voltage: 6.3 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: 8750 Ω
Transconductance: 0.0012 S
Amplification factor: 10.5
Max plate voltage: 250 V
Max plate dissipation: 2.5 W

Published ratings/characteristics promoted where directly applicable; identical twin sections are compressed to one section row.

Section 2

Triode

X-ray radiationInterelectrode capacitances

Plate resistance: 8750 Ω
Transconductance: 0.0012 S
Amplification factor: 10.5
Max plate voltage: 250 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

1938 Raytheon Amateur

Published operating points and test conditions from this source.

SECTION 1

Triode

Characteristics

Heater or filament voltage
6.3 V
Published nominal value
Heater or filament current
600 mA
Published nominal value
Transconductance
1200 µS
Published characteristic
Amplification factor
10.5
Published characteristic

Other

Maximum plate dissipation
2.5 W
Published maximum or highest stated rating
RF power output
3.5 W
ClassC; OneTube
Maximum operating frequency
60 MHz
Full ratings