6761

Power/output pentode designed for audio, broadband, telephone, industrial, or general power-amplifier service.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: 9A
Socket code: B9A
Base pins: 9
Nominal heater: 6.3 V / 350 mA

Description

Power amplifier pentode for telephone and industrial equipment, particularly broadband output amplifiers.

Socket description

Small-button Noval 9-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: 9A
Socket code: B9A
Base pins: 9
Nominal heater voltage: 6.3 V
Nominal heater current: 350 mA
Parallel heater voltage: 6.3 V
Parallel heater current: 350 mA
Series capable: No

9A - Terminal pinout

Electrical assignments shared by every tube using this base designation.

Terminal	Section	Connection	Evidence
PIN12P	B	P — Plate (Anode) EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 130, 9A
PIN22G1	B	G1 — Control Grid EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 130, 9A
PIN32K	B	K — Cathode EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 130, 9A
PIN4H	—	H — Heater EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 130, 9A
PIN5H	—	H — Heater EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 130, 9A
PIN61P	A	P — Plate (Anode) EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 130, 9A
PIN71G1	A	G1 — Control Grid EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 130, 9A
PIN81K	A	K — Cathode EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 130, 9A
PIN9HCT	—	HCT — Heater Center Tap EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 130, 9A

Section ratings

1 physical section, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 23000 Ω
Transconductance: 0.013 S
Max plate voltage: 300 V
Max screen voltage: 220 V
Max plate dissipation: 10 W
Max screen dissipation: 1.65 W

Published maximum ratings and characteristic constants promoted; identical twin sections compressed when 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

195X General Electric Essential Characteristics

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Maximum plate voltage
300 V
Published handbook rating
Plate voltage
250 V
ClassA
Control-grid bias
3 V
ClassA
Plate current
1 mA
ClassA
Alternate plate voltage
100 V
ClassA OperatingPoint2
Alternate control-grid bias
1 V
ClassA OperatingPoint2
Alternate plate current
0.8 mA
ClassA OperatingPoint2

Characteristic

Plate resistance
58000 ohm
Published handbook characteristic
Transconductance
1200 µS
Published handbook characteristic
Amplification factor
70
Published handbook characteristic
Heater/filament voltage
6.3 V
Published heater/filament rating
Heater/filament current
350 mA
Published heater/filament rating
Alternate plate resistance
58000 ohm
ClassA OperatingPoint2
Alternate transconductance
1200 µS
ClassA OperatingPoint2
Alternate amplification factor
70
ClassA OperatingPoint2

Capacitance

Input capacitance
1.4 pF
Published capacitance column
Output capacitance
0.46 pF
Published capacitance column
Grid-to-plate capacitance
1.4 pF
Published capacitance column

Data set 02

1965 Ericsson Longlife

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Plate supply voltage
130 V
ClassA
Screen-grid supply voltage
130 V
ClassA
Cathode bias resistor
100 Ohm
ClassA
Plate current
70 mA
ClassA
Screen-grid current
3.5 mA
ClassA
Load resistance
1500 Ohm
ClassA
Power output
3 W
ClassA
Total harmonic distortion
10 %
ClassA
Transconductance minimum
11000 uS
Transconductance maximum
15000 uS
Plate current maximum
84 mA
Screen-grid current maximum
7 mA

Characteristics

Transconductance
13000 uS
ClassA
Plate resistance
23000 Ohm
ClassA
Screen-to-control-grid amplification factor
8 ratio
ClassA

Data set 03

196X LM Ericsson

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristics

Heater voltage
6.3 V
Heater current
1 A
Plate resistance
100 ohm
Amplification factor
2

Other

Maximum plate voltage
275 V
Maximum screen voltage
220 V
Maximum plate dissipation
1 W
Maximum screen dissipation
1.65 W