6SF7

Diode-pentode combination for detector and voltage-amplifier service. The pentode provides useful gain and high output resistance while the diode supplies complementary detector or control-voltage rectification.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: 7AZ
Socket code: IO
Base pins: 8
Nominal heater: 6.3 V / 300 mA

Description

Combined diode and remote-cutoff pentode for detector and amplifier service.

Socket description

International Octal

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: 7AZ
Socket code: IO
Base pins: 8
Nominal heater voltage: 6.3 V
Nominal heater current: 300 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

7AZ - Terminal pinout

Electrical assignments shared by every tube using this base designation.

Terminal	Section	Connection	Evidence
PIN1SH	A	SH — Internal Shield Source EIA label SH; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 7AZ
PIN21G1	A	G1 — Control Grid Source EIA label 1G1; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 7AZ
PIN31G3	A	G3 — Suppressor GridGroup 7AZ3 Source EIA label 1G3; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 7AZ
PIN3K	A	K — CathodeGroup 7AZ3 Source EIA label K; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 7AZ
PIN41G2	A	G2 — Screen Grid Source EIA label 1G2; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 7AZ
PIN52P	B	P — Plate (Anode) Source EIA label 2P; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 7AZ
PIN61P	A	P — Plate (Anode) Source EIA label 1P; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 7AZ
PIN7H	—	H — Heater Source EIA label H; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 7AZ
PIN8H	—	H — Heater Source EIA label H; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 128, 7AZ

Section ratings

2 physical sections, each with unique specifications.

Section 1

Diode

X-ray radiationInterelectrode capacitances

Rectifier peak inverse voltage: 330 V

Published promoted fields populated from printed headings; identical repeated sections compressed.

Section 2

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 700000 Ω
Transconductance: 0.00205 S
Max plate voltage: 300 V
Max screen voltage: 100 V
Max plate dissipation: 2.5 W
Max screen dissipation: 0.5 W

Published promoted fields populated from printed headings; identical repeated sections compressed.

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 2

Pentode

Other

Maximum plate voltage
300 V
Published handbook rating
Maximum screen voltage
100 V
Published handbook rating
Plate voltage
250 V
ClassA OperatingPoint1
Screen voltage
100 V
ClassA OperatingPoint1
Control-grid bias
1 V
ClassA OperatingPoint1
Plate current
12.4 mA
ClassA OperatingPoint1
Screen current
3.3 mA
ClassA OperatingPoint1

Characteristic

Plate resistance
700000 ohm
ClassA OperatingPoint1
Transconductance
2050 µS
ClassA OperatingPoint1
Heater voltage
6.3 V
Published heater rating
Heater current
300 mA
Published heater rating

Data set 02

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 2

Pentode

Characteristic

PentodeTransconductance
2050 uS
Section2