4DT6A

Dual-control sharp-cutoff miniature pentode used primarily as an FM detector in color and black-and-white television receivers. Its independently effective control grids provide the specialized detector and control characteristics required in television sound circuitry.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: 7EN
Socket code: B7G
Base pins: 7
Nominal heater: 4.2 V / 450 mA

Description

Miniature sharp-cutoff pentode used as an FM detector in color and black-and-white television receivers.

Socket description

Miniature 7-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: 7EN
Socket code: B7G
Base pins: 7
Nominal heater voltage: 4.2 V
Nominal heater current: 450 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

7EN - Terminal pinout

Electrical assignments shared by every tube using this base designation.

Terminal	Section	Connection	Evidence
PIN1G1	A	G1 — Control Grid Chart transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 7EN
PIN2IS	A	IS — Internal ScreenGroup 7EN2 Chart transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 7EN
PIN2K	A	K — CathodeGroup 7EN2 Chart transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 7EN
PIN3H	—	H — Heater Chart transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 7EN
PIN4H	—	H — Heater Chart transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 7EN
PIN5P	A	P — Plate (Anode) Chart transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 7EN
PIN6G2	A	G2 — Screen Grid Chart transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 7EN
PIN7G3	A	G3 — Suppressor Grid Chart transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 7EN

Section ratings

1 physical section, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 150000 Ω
Transconductance: 0.007 S
Max plate voltage: 330 V
Max screen voltage: 330 V
Max plate dissipation: 2 W
Max screen dissipation: 1.1 W

Reference/equivalence-only source: base-type electrical ratings/characteristics are not reproduced in the approved PDF; promoted values intentionally not inferred. Electrical ratings/characteristics inherited from the explicitly referenced 6-volt parent type; supplied sheet changes heater characteristics.

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

1971 RCA HB3 Binder 4 of 7

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Heater Current
420 mA to 480 mA
Published nominal ± tolerance
Heater Voltage
4.2 V
At heater current 0.45 A
Warm-Up Time
11 s
Average
Plate Voltage
330 V
Inherited from explicitly referenced 6-volt parent type; heater variant
Screen Supply Voltage
330 V
Inherited from explicitly referenced 6-volt parent type; heater variant

Characteristics

Transconductance
7000 µS
Inherited from explicitly referenced 6-volt parent type; heater variant

Data set 02

1975 RCA RC30

Published operating points and test conditions from this source.

SECTION 1

Pentode

Capacitance

Grid No.1 to Plate
0.02 pF
Capacitance
Grid No.1 to Cathode/Heater/Grid No.2/Grid No.3/Internal Shield
5.8 pF
Capacitance
Grid No.3 to Plate
1.7 pF
Capacitance

Characteristic

Plate Supply Voltage
160 V
ClassA
Grid-No.2 Supply Voltage
100 V
ClassA
Cathode-Bias Resistor
560 ohm
ClassA
Transconductance Grid No.1 to Plate
1350 uS
ClassA
Transconductance Grid No.3 to Plate
515 uS
ClassA
Plate Current
1.55 mA
ClassA
Grid-No.2 Current
1.8 mA
ClassA