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

2G22

Battery triode-heptode combining local oscillation and frequency conversion at very low operating power. The triode supplies oscillator action while the heptode performs mixing in compact portable equipment.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: 2G21
Socket code: B7G
Base pins: 7
Nominal heater: 1.25 V / 50 mA

Description

Subminiature triode-heptode frequency converter for combined mixer and oscillator service.

Socket description

Miniature 7-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: 2G21
Socket code: B7G
Base pins: 7
Nominal heater voltage: 1.25 V
Nominal heater current: 50 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

2G21 - 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

Transconductance: 0.0006 S
Amplification factor: 20
Max plate voltage: 45 V
Max plate dissipation: 0.1 W
Max cathode current: 2 mA

Promoted from clearly identified printed ratings/characteristics; additional published operating points and capacitances retained in TUBE_SECTION_PARAMETER.

Section 2

Heptode

X-ray radiationInterelectrode capacitances

Plate resistance: 500000 Ω
Transconductance: 0.00006 S
Max plate voltage: 45 V
Max screen voltage: 45 V
Max plate dissipation: 0.1 W
Max cathode current: 2 mA

Promoted from clearly identified printed ratings/characteristics; additional published operating points and capacitances retained in TUBE_SECTION_PARAMETER.

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

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

HeaterVoltageNominal
1.25 V
Nominal
HeaterCurrentNominal
50 mA
Nominal
Maximum Plate Voltage
45 V
Maximum Plate Dissipation
0.1 W
Maximum Cathode Current
2 mA

Characteristic

Transconductance
600 µS
Typical
Amplification Factor
20
Typical

SECTION 2

Heptode

Other

HeaterVoltageNominal
1.25 V
Nominal
HeaterCurrentNominal
50 mA
Nominal
Maximum Plate Voltage
45 V
Maximum Screen Voltage
45 V
Maximum Plate Dissipation
0.1 W
Maximum Cathode Current
2 mA

Characteristic

Transconductance
250 µS
Typical

Data set 02

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Oscillator plate voltage
22.5 V
Converter
Oscillator plate current
1 mA
Converter
Oscillator grid current
0.03 mA
Converter
Oscillator grid resistor
50000 Ω
Converter

SECTION 2

Heptode

Other

Plate voltage
22.5 V
Converter
Screen voltage
22.5 V
Converter
Control-grid voltage
0 V
Converter
Plate current
0.2 mA
Converter
Screen current
0.3 mA
Converter

Characteristic

Plate resistance
500000 Ω
Converter
Conversion transconductance
60 µS
Converter

Data set 03

195X Raytheon Special Purpose Tubes

Published operating points and test conditions from this source.

SECTION 1

Triode

Other

Plate Voltage
22.5 V
TriodeSection
Plate Current
1 mA
TriodeSection

SECTION 2

Heptode

Other

Plate Voltage
22.5 V
Grid 1 Voltage
Rg=50000 ohm V
Grid 2 Voltage
22.5 V
Grid 3 Voltage
0 V
Plate Current
0.2 mA
Grid 2 Current
0.3 mA

Characteristic

Transconductance
60 uS
Plate Resistance
0.5 Mohm