1644

Special-quality twin-pentode power amplifier related to the 12L8GT family, intended for dependable power-amplifier service.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 2
Base: 8BU
Socket code: -
Base pins: 8
Nominal heater: 12.6 V / 150 mA

Description

Special-quality twin-pentode power amplifier related to the 12L8GT family.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: 8BU
Socket code: -
Base pins: 8
Nominal heater voltage: 12.6 V
Nominal heater current: 150 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

8BU - Terminal pinout

Electrical assignments shared by every tube using this base designation.

Terminal	Section	Connection	Evidence
PIN11G1	A	G1 — Control Grid EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 8BU
PIN21G3	A	G3 — Suppressor GridGroup 8BU2 EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 8BU
PIN2K	A	K — CathodeGroup 8BU2 EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 8BU
PIN22G3	B	G3 — Suppressor GridGroup 8BU2 EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 8BU
PIN32G1	B	G1 — Control Grid EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 8BU
PIN42P	B	P — Plate (Anode) EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 8BU
PIN51G2	A	G2 — Screen GridGroup 8BU5 EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 8BU
PIN52G2	B	G2 — Screen GridGroup 8BU5 EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 8BU
PIN6H	—	H — Heater EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 8BU
PIN7H	—	H — Heater EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 8BU
PIN81P	A	P — Plate (Anode) EIA transcription; manufacturer confirmation pending	Unverified EIA Base Connections, printed page 129, 8BU

Section ratings

2 physical sections, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 160000 Ω
Transconductance: 0.00215 S
Max plate voltage: 180 V
Max screen voltage: 180 V

Promoted from printed maximum-rating/characteristic columns; additional published values retained in TUBE_SECTION_PARAMETER.

Section 2

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 160000 Ω
Transconductance: 0.00215 S
Max plate voltage: 180 V
Max screen voltage: 180 V

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
5 pF
EachSection
Output capacitance
6 pF
EachSection
Grid-to-plate capacitance
0.7 pF
EachSection

Other

Plate voltage
180 V
ClassA;EachSection
Screen voltage
180 V
ClassA;EachSection
Control-grid voltage
-9 V
ClassA;EachSection
Plate current
13 mA
ClassA;EachSection
Screen current
2.8 mA
ClassA;EachSection
Load resistance
10000 Ω
ClassA;EachSection
Power output
1 W
ClassA;EachSection

Characteristic

Plate resistance
160000 Ω
EachSection
Transconductance
2150 µS
EachSection