1AJ4

Directly heated remote-cutoff RF pentode with a 1.4 V, 25 mA filament. Designed for Class A high-frequency amplification, it combines low filament drain with variable-gain capability for portable battery receivers.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: 6AR
Socket code: B7G
Base pins: 7
Nominal heater: 1.4 V / 25 mA

Description

Directly heated remote-cutoff RF pentode with a 1.4 V, 25 mA filament for Class-A radio-frequency amplification.

Socket description

Miniature 7-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: 6AR
Socket code: B7G
Base pins: 7
Nominal heater voltage: 1.4 V
Nominal heater current: 25 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

6AR - Terminal pinout

Electrical assignments shared by every tube using this base designation.

Terminal	Section	Connection	Evidence
PIN1G3	A	G3 — Suppressor GridGroup 6AR1 Original EIA label G3; independent manufacturer confirmation pending	Unverified EIA Base Connections, printed page 127, 6AR
PIN1IS	A	IS — Internal ScreenGroup 6AR1 Original EIA label IS; independent manufacturer confirmation pending	Unverified EIA Base Connections, printed page 127, 6AR
PIN1F	—	F — FilamentGroup 6AR1 Original EIA label F; independent manufacturer confirmation pending	Unverified EIA Base Connections, printed page 127, 6AR
PIN2P	A	P — Plate (Anode) Original EIA label P; independent manufacturer confirmation pending	Unverified EIA Base Connections, printed page 127, 6AR
PIN3G2	A	G2 — Screen Grid Original EIA label G2; independent manufacturer confirmation pending	Unverified EIA Base Connections, printed page 127, 6AR
PIN4IC	—	IC Original EIA label IC; independent manufacturer confirmation pending	Unverified EIA Base Connections, printed page 127, 6AR
PIN5G3	A	G3 — Suppressor GridGroup 6AR5 Original EIA label G3; independent manufacturer confirmation pending	Unverified EIA Base Connections, printed page 127, 6AR
PIN5IS	A	IS — Internal ScreenGroup 6AR5 Original EIA label IS; independent manufacturer confirmation pending	Unverified EIA Base Connections, printed page 127, 6AR
PIN5F	—	F — FilamentGroup 6AR5 Original EIA label F; independent manufacturer confirmation pending	Unverified EIA Base Connections, printed page 127, 6AR
PIN6G1	A	G1 — Control Grid Original EIA label G1; independent manufacturer confirmation pending	Unverified EIA Base Connections, printed page 127, 6AR
PIN7F	—	F — Filament Original EIA label F; independent manufacturer confirmation pending	Unverified EIA Base Connections, printed page 127, 6AR

Section ratings

1 physical section, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 1000000 Ω
Transconductance: 0.00075 S
Max plate voltage: 90 V
Max screen voltage: 90 V
Max plate dissipation: 0.25 W
Max screen dissipation: 0.1 W
Max cathode current: 2.2 mA

Promoted from the printed condensed-manual maximum/characteristic columns; operating-point values are 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

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Pentode

Capacitance

Input capacitance
3.3 pF
Section1
Output capacitance
7.8 pF
Section1
Grid-to-plate capacitance
0.01 pF
Section1

Other

Plate voltage
64 V
ClassA
Screen voltage
64 V
ClassA
Control-grid voltage
0 V
ClassA
Plate current
1.65 mA
ClassA
Screen current
0.55 mA
ClassA

Characteristic

Plate resistance
1000000 Ω
ClassA
Transconductance
750 µS
ClassA

Data set 02

1961 Ferranti Technical Handbook

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

HeaterOrFilamentVoltage
1.4 V
HeaterOrFilamentCurrent
25 mA
CutoffCharacteristic
Variable mu

Data set 03

1999 Philips 0-D

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristic

Filament voltage
1.4 V
Filament voltage 1.4 volts
Filament current
25 mA
Filament current 25 m amps
except plate
343 pF
except plate 343 uuF
Battery voltage
90 V
Battery voltage 90 volts™)
Plate voltage
90 V
Plate voltage 90 volts
Plate dissipation
0.25 watt
Plate dissipation 0.25 watt
Grid No
2 V
Grid No.2 voltage 90 volts
Grid No
90 V
Grid No.2 voltage 90 volts
Grid Ko.2 dissipation
0.1 watt
Grid Ko.2 dissipation 0.1 watt
Cathode current
2.2 mA
Cathode current 2.2 m amps
Grid No
1 c
Grid No.1 circuit resistance 3 megohms
Grid No
3 megohms
Grid No.1 circuit resistance 3 megohms
Grid No
1 V
Grid No.1 voltage when grid
No
1 c
No.1 current = + 0.3 pamp -0.2 volt
No
0.3 pa
No.1 current = + 0.3 pamp -0.2 volt
No
-0.2 V
No.1 current = + 0.3 pamp -0.2 volt
Grid No.1 bias 0 5.5 70 —
4.17 V
Grid No.1 bias 0 5.5 70 —4.17 volts
Grid No
64 V
Grid No.2 voltage 64 85 64 64 volts
Grid No
2 c
Grid No.2 current 0.55 - 0.55 - m amp
Transconductance 750 10 750
10 µS
Transconductance 750 10 750 10 micromhos
Plate resistance 0.7 >5 1.0 >
5 megohms
Plate resistance 0.7 >5 1.0 >5 megohms
voltage is
110 V
voltage is 110 volts
+) Based on a supply voltage of 90 or
67.5 V
+) Based on a supply voltage of 90 or 67.5 volts re-
Plate voltage=64
-85 V
- Plate voltage=64-85volts : o
Plate voltage
85 V
- Plate voltage=85volts C .4 ARk ®
Plate voltage
4 A
- Plate voltage=85volts C .4 ARk ®
Battery voltage
85 V
- Battery voltage=85volts y.avi 47 y. 5
5 Plate voltage
64 V
5 Plate voltage=64volts 1117 =
Grid3 No2 voltage=—
64 V
- Grid3 No2 voltage=—64volts~ | F Ry,
Plate voltage
64 v
= Plate voltage=64volfs 4 8
1 Grid No2 voltage=6‘
4 v
1 Grid No2 voltage=6‘4votts\ /i =
Plate voltage
64 V
Plate voltage =64volts
Grid No2 voltage
84 V
Grid No2 voltage 84volts
Battery voltage &
5 V
Battery voltage &5volts

Other

Plate to grid No
1 mA
Plate to grid No.1 max. Q.01 puF