6J8GA

Triode-heptode oscillator-converter for superheterodyne receiving service. The triode supplies local oscillation while the heptode mixer offers exceptionally high output resistance for strong converter-circuit isolation.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: -
Socket code: IO
Base pins: 8
Nominal heater: 6.3 V / 450 mA

Description

Triode-heptode converter combining a local oscillator triode with a heptode mixer for receiver frequency conversion.

Socket description

International Octal

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: -
Socket code: IO
Base pins: 8
Nominal heater voltage: 6.3 V
Nominal heater current: 450 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

Heptode

X-ray radiationInterelectrode capacitances

Plate resistance: 4000000 Ω
Max plate voltage: 300 V
Max screen voltage: 100 V
Max plate dissipation: 0.9 W

Published ratings and characteristics promoted where clearly stated; identical repeated diode/triode sections compressed where applicable.

Section 2

Triode

X-ray radiationInterelectrode capacitances

Plate resistance: 10600 Ω
Transconductance: 0.0016 S
Amplification factor: 17
Max plate voltage: 250 V
Max plate dissipation: 0.8 W

Published ratings and characteristics promoted where clearly stated; identical repeated diode/triode sections compressed where applicable.

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

1940 RCA

Published operating points and test conditions from this source.

SECTION 1

Heptode

Characteristics

Heater voltage
6.3 V
Published nominal value
Heater current
450 mA
Published nominal value
Heptode plate resistance
4 Mohm
At published operating point

Other

Maximum plate dissipation
0.9 W
Published maximum or stated design maximum
Conversion transconductance
290 µS
Converter service

SECTION 2

Triode

Characteristics

Heater voltage
6.3 V
Published nominal value
Heater current
450 mA
Published nominal value
Transconductance
1600 µS
Published operating characteristic
Amplification factor
17
Published operating characteristic

Other

Maximum plate dissipation
0.8 W
Published maximum or stated design maximum