12HG7

Frame-grid sharp-cutoff pentode designed for television video-amplifier service. Its specialized grid construction provides high transconductance and bandwidth for color and monochrome television signal amplification.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: 9BF
Socket code: B9A
Base pins: 9
Nominal heater: 12.6 V / 260 mA

Description

Frame-grid sharp-cutoff pentode for video-amplifier service in color and black-and-white television receivers.

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: 9BF
Socket code: B9A
Base pins: 9
Nominal heater voltage: 12.6 V
Nominal heater current: 260 mA
Parallel heater voltage: 6.3 V
Parallel heater current: 520 mA
Series capable: Yes

9BF - Terminal pinout

Electrical assignments shared by every tube using this base designation.

Terminal	Section	Connection	Evidence
PIN1K	A	K — Cathode EIA chart transcription; manufacturer corroboration pending	Unverified EIA Base Connections, printed page 131, 9BF
PIN2G1	A	G1 — Control Grid EIA chart transcription; manufacturer corroboration pending	Unverified EIA Base Connections, printed page 131, 9BF
PIN3G3	A	G3 — Suppressor Grid EIA chart transcription; manufacturer corroboration pending	Unverified EIA Base Connections, printed page 131, 9BF
PIN4H	—	H — Heater EIA chart transcription; manufacturer corroboration pending	Unverified EIA Base Connections, printed page 131, 9BF
PIN5H	—	H — Heater EIA chart transcription; manufacturer corroboration pending	Unverified EIA Base Connections, printed page 131, 9BF
PIN6HCT	—	HCT — Heater Center Tap EIA chart transcription; manufacturer corroboration pending	Unverified EIA Base Connections, printed page 131, 9BF
PIN7P	A	P — Plate (Anode) EIA chart transcription; manufacturer corroboration pending	Unverified EIA Base Connections, printed page 131, 9BF
PIN8G2	A	G2 — Screen Grid EIA chart transcription; manufacturer corroboration pending	Unverified EIA Base Connections, printed page 131, 9BF
PIN9G3	A	G3 — Suppressor Grid EIA chart transcription; manufacturer corroboration pending	Unverified EIA Base Connections, printed page 131, 9BF

Section ratings

1 physical section, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 60000 Ω
Transconductance: 0.032 S
Max plate voltage: 400 V
Max screen voltage: 330 V
Max plate dissipation: 10 W
Max screen dissipation: 1 W
Max cathode current: 40 mA

Promoted gm/rp from published Class-A characteristics; maximum screen input is condition-dependent above 165 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

1964 RMA EIA

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Plate supply voltage
300 V
ClassA
Grid No. 2 supply voltage
135 V
ClassA
Cathode resistor
47 Ohm
ClassA
Plate current
31 mA
ClassA
Grid No. 2 current
4.8 mA
ClassA
Maximum screen input
1 W
GridNo2VoltageUpTo165V
Fixed-bias grid circuit resistance maximum
0.1 Mohm
Cathode-bias grid circuit resistance maximum
0.25 Mohm

Capacitance

Grid No. 1 to plate capacitance
0.12 pF
Input capacitance
14 pF
Output capacitance
4.4 pF

Data set 02

1971 RCA HB3 Binder 5 of 7

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Heater voltage
12.6 V
Heater current
260 mA
Heater voltage series
12.6 V
Heater current series
260 mA
Heater voltage parallel
6.3 V
Heater current parallel
520 mA
Peak heater-cathode voltage heater negative
200 V
Peak heater-cathode voltage heater positive
200 V
Plate supply voltage
300 V
ClassA
Screen supply voltage
135 V
ClassA
Cathode resistor
47 ohm
ClassA
Plate current
31 mA
ClassA
Screen current
4.8 mA
ClassA
Maximum plate voltage
400 V
Maximum screen supply voltage
330 V
Screen input up to 165 V
1 W
Plate dissipation
10 W

Characteristic

Plate resistance
60000 ohm
ClassA
Transconductance
32000 uS
ClassA

Capacitance

Grid-to-plate capacitance
0.15 pF
Input capacitance
20 pF
Output capacitance
7 pF