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Voltage - Triode (with diode, heptode or hexode) ·Hexode-Triode

X41

Radio receiver frequency changer designed for superheterodyne mixer and oscillator service. Its multi-grid construction performs signal conversion, often integrating local oscillation and mixing within one valve.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: -
Socket code: B7
Base pins: 7
Nominal heater: 4 V / 1.2 A

Description

An indirectly heated triode-hexode mixer/first-detector/frequency-changer valve with a common cathode, low interaction between sections and suitability for short-wave reception.

Socket description

Medium 7-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: B7
Base pins: 7
Nominal heater voltage: 4 V
Nominal heater current: 1.2 A
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

Max plate voltage: 150 V

Osram X41 common-cathode indirectly heated triode-hexode receiving frequency changer. The oscillator triode maximum anode rating is 150 V and recommended operating value is 100 V. Do not confuse the separate hexode anode maximum of 250 V with the oscillator anode limit. Heater 4 V 1.2 A; triode grid drives mixer grid internally.

Section 2

Hexode

X-ray radiationInterelectrode capacitances

Max plate voltage: 250 V
Max screen voltage: 80 V

Osram X41 variable-mu hexode mixer of a 4 V 1.2 A triode-hexode frequency changer. Maximum screen voltage 80 V; manufacturer-recommended typical screen operating voltage 70 V. Hexode anode rated 250 V. Published conversion conductance about 640 µS and conversion impedance about 0.75 MΩ are operating converter characteristics, not ordinary static transconductance or plate resistance. Both sections share an indirectly heated cathode.

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

1937 Osram Valves

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Oscillator Anode Voltage
150 V
Triode oscillator section
Oscillator Grid Peak Swing
12 V
Triode oscillator section

SECTION 2

Hexode

Other

Heater Voltage
4 V
Published datasheet value
Heater Current
1.2 A
Published datasheet value
Anode Voltage Maximum
250 V
Published datasheet value
Screen Voltage Maximum
80 V
Published datasheet value
Oscillator Anode Voltage
150 V
Published datasheet value

Characteristic

Conversion Conductance
640 µS
Published datasheet value

Data set 02

1955 Marconi

Published operating points and test conditions from this source.

SECTION 1

Triode

Application

Oscillator section function
Local oscillator

Other

Oscillator anode voltage
250 V

SECTION 2

Hexode

Construction

Mixer section identity
Hexode

Other

Mixer anode voltage
250 V
Mixer screen voltage
70 V

Application

Frequency-changer service
Explicit