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Voltage Pentode - Sharp Cutoff (single) ·Pentode

6CB6A

Sharp-cutoff high-transconductance pentode for television IF amplification and VHF tuner RF service.

Directly heatedCold cathodeCommon cathodeDissimilar

Sections: 1
Base: 7CM
Socket code: B7G
Base pins: 7
Nominal heater: 6.3 V / 300 mA

Description

Sharp-cutoff pentode used as a television IF amplifier to about 45 MHz and as an RF amplifier in VHF television tuners.

Socket description

Miniature 7-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base: 7CM
Socket code: B7G
Base pins: 7
Nominal heater voltage: 6.3 V
Nominal heater current: 300 mA
Parallel heater voltage: -
Parallel heater current: -
Series capable: No

7CM - Terminal pinout

Electrical assignments shared by every tube using this base designation.

Terminal	Section	Connection	Evidence
PIN1G1	A	G1 — Control Grid EIA chart transcription; manufacturer verification pending	Unverified EIA Base Connections, printed page 128, 7CM
PIN2K	A	K — Cathode EIA chart transcription; manufacturer verification pending	Unverified EIA Base Connections, printed page 128, 7CM
PIN3H	—	H — Heater EIA chart transcription; manufacturer verification pending	Unverified EIA Base Connections, printed page 128, 7CM
PIN4H	—	H — Heater EIA chart transcription; manufacturer verification pending	Unverified EIA Base Connections, printed page 128, 7CM
PIN5P	A	P — Plate (Anode) EIA chart transcription; manufacturer verification pending	Unverified EIA Base Connections, printed page 128, 7CM
PIN6G2	A	G2 — Screen Grid EIA chart transcription; manufacturer verification pending	Unverified EIA Base Connections, printed page 128, 7CM
PIN7G3	A	G3 — Suppressor GridGroup 7CM7 EIA chart transcription; manufacturer verification pending	Unverified EIA Base Connections, printed page 128, 7CM
PIN7IS	A	IS — Internal ScreenGroup 7CM7 EIA chart transcription; manufacturer verification pending	Unverified EIA Base Connections, printed page 128, 7CM

Section ratings

1 physical section, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances

Plate resistance: 280000 Ω
Transconductance: 0.008 S
Max plate voltage: 330 V
Max screen voltage: 330 V
Max plate dissipation: 2.3 W
Max screen dissipation: 0.55 W
Max cathode current: 30 mA

Published ratings and characteristics promoted from approved datasheet.

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

1966 Tung Sol Electronic Tubes 2 of 4

Published operating points and test conditions from this source.

SECTION 1

Pentode

Capacitance

Grid-to-plate capacitance without shield
0.025 pF
Grid-to-plate capacitance with shield
0.015 pF
Input capacitance
6.5 pF
Output capacitance without shield
2 pF
Output capacitance with shield
3 pF

Other

Plate voltage
125 V
ClassA
Grid #2 voltage
125 V
ClassA
Cathode bias resistor
56 ohm
ClassA
Plate current
13 mA
ClassA
Grid #2 current
3.7 mA
ClassA
Heater warm-up time
11 s

Characteristic

Grid #1 voltage at 20 uA plate current
-6.5 V

Data set 02

1971 RCA HB3 Binder 3 of 7

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

Heater voltage
6.3 V
Nominal
Heater current
300 mA
Nominal
Maximum plate voltage
330 V
Promoted published value
Maximum screen voltage
330 V
Promoted published value
Maximum plate dissipation
2.3 W
Promoted published value
Voltage (AC or DC)
6.3 V
Heater Characteristics and Ratings fAhsolute-Maximum Valuesl:
Current at heater volts =
300 V
Heater Characteristics and Ratings fAhsolute-Maximum Valuesl:
respect to cathode
200 V
Heater Characteristics and Ratings fAhsolute-Maximum Valuesl:
Grid No.1 to plate
0.015 mA
Direct Interelectrode Capacitances:
Plate Supply Voltage
125 V
Characteristics, Class AI pmol if ier:
Grid-No.2 Supply Voltage
125 V
Characteristics, Class AI pmol if ier:
Grid-No.1 Voltage
-3 V
Characteristics, Class AI pmol if ier:
Cathode Resistor
56 ohm
Characteristics, Class AI pmol if ier:
Plate Resistance (Approx )
0.28 megohm
Characteristics, Class AI pmol if ier:
Transconductance
8000 uS
Characteristics, Class AI pmol if ier:
Plate Current
13 mA
Characteristics, Class AI pmol if ier:
Grid-No.2 Current - •3.7 ma
3.7 mA
Characteristics, Class AI pmol if ier:
plate µa =
-6.5 V
Characteristics, Class AI pmol if ier:
PLATE VOLTAGE
330 V
Maximum Ratings, Absolute-Maximum Values:
GRID-No.2 (SCREEN-GRID) SUPPLY VOLTAGE.
330 V
Maximum Ratings, Absolute-Maximum Values:
GRIC-No.2 VOLTAGE See Grid-No.a Input Rating Chart
2 V
Maximum Ratings, Absolute-Maximum Values:
GRID-No.1 (CONTROL~RID) VOLTAGE
1 V
Maximum Ratings, Absolute-Maximum Values:
For grid-No.2 voltages
2 V
Maximum Ratings, Absolute-Maximum Values:
For grid-No.2 voltages be
2 V
Maximum Ratings, Absolute-Maximum Values:
tween
2 V
Maximum Ratings, Absolute-Maximum Values:
PLATE DISSIPATION
2.3 W
Maximum Ratings, Absolute-Maximum Values:
to voltage variations as great asf
20 V
Maximum Ratings, Absolute-Maximum Values:
With heater volts =
125 V
Maximum Ratings, Absolute-Maximum Values:
No.3 connected to cathode at socket, grid-No.2 supply volts =
2 V
Maximum Ratings, Absolute-Maximum Values:
125, and cathode resistor (ohms) bypassed =
56 ohm
Maximum Ratings, Absolute-Maximum Values:

Characteristic

Plate resistance
280000 ohm
Promoted published value
Transconductance
8000 uS
Promoted published value

Data set 03

1971 RCA HB3 Binder 4 of 7

Published operating points and test conditions from this source.

SECTION 1

Pentode

Characteristics

Warn~up time (Average)
11 s
Plate-Supply Voltage
125 V
Published table column 1 of 2
Plate-Supply Voltage
125 V
Published table column 2 of 2
Grid-No.i Voltage
-3 V
Cathode Resistor
56 Ω
Plate Resistance (Approx )
0.28 MΩ
Transconductance
8000 µS
Plate Current
2.8 mA
Published table column 1 of 2
Plate Current
13 mA
Published table column 2 of 2
for plate µa =
20 V
Published table column 1 of 2
for plate µa =
-6.5 V
Published table column 2 of 2
E f=
63 V
GRID-Ns
2 V
Published table column 1 of 2
GRID-Ns
125 V
Published table column 2 of 2
Ef=
6.3 V
PLATE VOLTS=
125 V
GRID—N~
2 V
Published table column 1 of 2
GRID—N~
125 V
Published table column 2 of 2

Capacitance

Grid No.l to plate
0.025 pF
Published table column 1 of 2
Grid No.l to plate
0.015 pF
Published table column 2 of 2
No
2 pF
Published table column 1 of 3
No
2 pF
Published table column 2 of 3
No
3 pF
Published table column 3 of 3

Other

PLATE VOLTAGE
330 V
Positive-bias value
0 V
to
165 W
Published table column 1 of 2
to
0.55 W
Published table column 2 of 2
tween
165 V
Published table column 1 of 2
tween
330 V
Published table column 2 of 2
PLATE DISSIPATION
2.3 W
respect to cathode
200 V
For fixed-bias operation
0.25 MΩ
For cathode-bias operation
1 MΩ
The do component must not exceed
100 V

Data set 04

1975 RCA RC30

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

about
45 MHz
Published in approved 6CB6A target datasheet entry; Section1
Heater Voltage (ac/dc) 3.15 4.2
6.3 V
Published in approved 6CB6A target datasheet entry; Section1
Heater Current 0.6 0.45
300 mA
Published in approved 6CB6A target datasheet entry; Section1
Heater Warm-up Time (Average) 11 11
11 seconds
Published in approved 6CB6A target datasheet entry; Section1
Plate Voltage
330 V
Published in approved 6CB6A target datasheet entry; Section1
Grid-No.S (Suppressor-Grid) Voltage, Positive value
0 V
Published in approved 6CB6A target datasheet entry; Section1
Grid-No.2 Supply Voltage
330 V
Published in approved 6CB6A target datasheet entry; Section1
Grid-No.l (Control-Grid) Voltage, Positive-bias value
0 V
Published in approved 6CB6A target datasheet entry; Section1
For grid-No.2 voltages between 165 and
330 V
Published in approved 6CB6A target datasheet entry; Section1
Plate Supply Voltage
125 V
Published in approved 6CB6A target datasheet entry; Section1
Cathode-Sias Resistor
56 Ω
Published in approved 6CB6A target datasheet entry; Section1
Grid-No.2 Current
3.7 mA
Published in approved 6CB6A target datasheet entry; Section1
Grid-No.l VoJt&ge (Approx.) for plate current of 20 jiA
-6.5 V
Published in approved 6CB6A target datasheet entry; Section1
Grid-No.l Voltage (Approx.) for plate current of
2.8 mA
Published in approved 6CB6A target datasheet entry; Section1
Grid-No.l Voltage (Approx.) for plate current of 2.8 mA
-3 V
Published in approved 6CB6A target datasheet entry; Section1

Capacitance

Grid No. 3. and Internal Shield 6.5
6.6 pF
Published in approved 6CB6A target datasheet entry; Section1