1L6

Battery pentagrid converter for portable superheterodyne receivers, combining local-oscillator and mixer functions in one multi-grid tube. Its economical filament minimizes battery drain while providing useful frequency conversion.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: 7DC
Socket code: B7G
Base pins: 7
Nominal heater: 1.4 V / 50 mA

Description

1L6 is listed as a pentagrid converter in the supplied receiving-tube handbook. It uses a 1.4 V, 0.05 A directly heated filament. The handbook publishes maximum ratings and representative operating characteristics for its intended 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: 7DC
Socket code: B7G
Base pins: 7
Nominal heater voltage: 1.4 V
Nominal heater current: 50 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

7DC - Terminal pinout

Electrical assignments shared by every tube using this base designation.

Terminal	Section	Connection	Evidence
PIN1F	—	F — Filament Source-transcribed; independent manufacturer verification pending	Unverified EIA Base Connections, printed page 129, 7DC
PIN2P	A	P — Plate (Anode) Source-transcribed; independent manufacturer verification pending	Unverified EIA Base Connections, printed page 129, 7DC
PIN3G2	A	G2 — Screen Grid Source-transcribed; independent manufacturer verification pending	Unverified EIA Base Connections, printed page 129, 7DC
PIN4G1	A	G1 — Control Grid Source-transcribed; independent manufacturer verification pending	Unverified EIA Base Connections, printed page 129, 7DC
PIN5G3	A	G3 — Suppressor GridGroup 7DC5 Source-transcribed; independent manufacturer verification pending	Unverified EIA Base Connections, printed page 129, 7DC
PIN5G5	A	G5 — Fifth GridGroup 7DC5 Source-transcribed; independent manufacturer verification pending	Unverified EIA Base Connections, printed page 129, 7DC
PIN6G4	A	G4 — Fourth Grid Source-transcribed; independent manufacturer verification pending	Unverified EIA Base Connections, printed page 129, 7DC
PIN7F	—	F — Filament Source-transcribed; independent manufacturer verification pending	Unverified EIA Base Connections, printed page 129, 7DC

Section ratings

1 physical section, each with unique specifications.

Section 1

Heptode

X-ray radiationInterelectrode capacitances

Plate resistance: 650000 Ω
Transconductance: 0.0003 S
Max plate voltage: 110 V
Max screen voltage: 65 V
Max cathode current: 4 mA

Pentagrid converter; conversion transconductance promoted; oscillator transconductance preserved separately.

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

1950 Sylvania

Published operating points and test conditions from this source.

SECTION 1

Heptode

Other

Typical Plate Voltage
90 V
Typical Grid No. 2 Voltage
90 V
Typical Grid No. 3 and 5 Voltage
45 V
Typical Plate Current
0.5 mA

Characteristic

Conversion Transconductance
300 µS
Grid No. 4 at 0 V
Conversion Transconductance
10 µS
Grid No. 4 at approx. -3.5 V
Oscillator Transconductance
550 µS

Data set 02

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Heptode

Other

Maximum plate voltage
110 V
Published handbook rating
Maximum screen voltage
65 V
Published handbook rating
Plate voltage
90 V
ClassA
Screen voltage
45 V
ClassA
Control-grid voltage
0 V
ClassA
Plate current
0.5 mA
ClassA
Screen current
0.6 mA
ClassA

Characteristic

Plate resistance
650000 ohm
Published handbook characteristic
Transconductance
300 µS
Published handbook characteristic
Filament voltage
1.4 V
DirectlyHeated DC filament
Filament current
50 mA
DirectlyHeated DC filament

Data set 03

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Heptode

Characteristic

Conversion Transconductance
300 uS
Converter
Oscillator Transconductance
650 uS
Oscillator