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Voltage Dual Pentode ·Pentode-Pentode

8CB11

Color-television Compactron with two sharp-cutoff pentodes for IF amplification, also usable as bandpass, burst, and low-level video amplifiers.

Directly heatedCold cathodeCommon cathodeDissimilar
Sections
2
Base
12DM
Socket code
B12C
Base pins
12
Nominal heater
8.4 V / 600 mA

Description

The 8CB11 is a Compactron containing two sharp-cutoff pentodes, intended primarily for intermediate-frequency amplifier service in color television receivers and also useful as bandpass, burst, and low-level video amplifiers.

Socket description

Duodecar 12-contact

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
12DM
Socket code
B12C
Base pins
12
Nominal heater voltage
8.4 V
Nominal heater current
600 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

12DM - Terminal pinout

Electrical assignments shared by every tube using this base designation.

No verified pinout is recorded for this base designation.

Section ratings

2 physical sections, each with unique specifications.

Section 1

Pentode

X-ray radiationInterelectrode capacitances
Plate resistance
200000 Ω
Transconductance
0.013 S
Max plate voltage
330 V
Max screen voltage
330 V
Max plate dissipation
3.1 W
Max screen dissipation
0.66 W

Representative row for two identical sharp-cutoff pentode sections; ratings and average characteristics are published per section.

Section 2

Pentode

X-ray radiationInterelectrode capacitances
Plate resistance
200000 Ω
Transconductance
0.013 S
Max plate voltage
330 V
Max screen voltage
330 V
Max plate dissipation
3.1 W
Max screen dissipation
0.66 W

Second physical sharp-cutoff pentode section; added to align rows with SectionCount.

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

1968 General Electric Co

Published operating points and test conditions from this source.

SECTION 1

Pentode

Other

  • COLOR TV TYPE TRANSCONDUCTANCE

    13000 uS

  • Cathode - Coated Unipotential (19 0 2p) MAXIMUM + s eeeeeeneenns

    0.004 pF

    GENERAL

  • Heater Voltage ACor DCx 8 4 Volts (191 to 2p) maximum

    0.001 pF

    GENERAL

  • Heater Currente 0 6+

    40 mA

    GENERAL

  • Heater Warm-up Time average 11 Seconds (291 to 1p) maximum

    0.002 pF

    GENERAL

  • Section 1 Section 2 191 to 2g1) maximum

    0.001 pF

    Direct Interelectrode Capacitances approximate Grid-Number 1

  • Input 1gtto(h+1k+ 192 +1g3+293 +i s )

    12 pF

    Input 1gtto(h+1k+ 192 +1g3+293 +i s ) 12 pf MECHANICAL

  • Grid-Number 1 to Plate (2g1to2p)

    0.02 pF

    Input 1gtto(h+1k+ 192 +1g3+293 +i s ) 12 pf MECHANICAL

  • Output 2pto (h +2k +2g2 + 293 + 1g3 + i s )

    2.8 pF

    Input 1gtto(h+1k+ 192 +1g3+293 +i s ) 12 pf MECHANICAL

  • Plate Voltage o oo et s

    330 V

    1270 MAXIMUM RATINGS

  • Screen Supply Voltage oot e

    330 V

    1270 MAXIMUM RATINGS

  • Positive DC Grid-Number 1 Voltage

    0 V

    1270 MAXIMUM RATINGS

  • Plate Dissipation

    3.1 W

    1270 MAXIMUM RATINGS

  • Screen Dissipation

    0.66 W

    1270 MAXIMUM RATINGS

  • DC Component

    100 V

    1270 MAXIMUM RATINGS

  • Total DC and Peak

    200 V

    1270 MAXIMUM RATINGS

  • With Cathode Bias vvvvier ettt eeeen

    0.25 MOhm

    1270 MAXIMUM RATINGS

  • PlateVoltageTypical

    125 V

    EachSection

  • ScreenVoltageTypical

    125 V

    EachSection

Characteristic

  • Grid-Number 1 to Plate (1gito1p)

    0.028 pF

    Direct Interelectrode Capacitances approximate Grid-Number 1

  • Plate Voltage

    125 V

    AVERAGE CHARACTERISTICS Each Section

  • Screen Voltage

    125 V

    AVERAGE CHARACTERISTICS Each Section

  • Cathode-Bias Resistor

    56 Ohm

    AVERAGE CHARACTERISTICS Each Section

  • Plate Resistance approximate

    0.2 MOhm

    AVERAGE CHARACTERISTICS Each Section

  • Transconductance

    13000 uS

    AVERAGE CHARACTERISTICS Each Section

  • Plate Current

    11 mA

    AVERAGE CHARACTERISTICS Each Section

  • Screen Current

    3.8 mA

    AVERAGE CHARACTERISTICS Each Section

  • b 20 Microamperes

    -3 V

    AVERAGE CHARACTERISTICS Each Section

  • Heater voltage for a bogey tube at If

    600 mA

    AVERAGE CHARACTERISTICS Each Section

  • The time required for the voltage across the heater to reach

    80 %

    AVERAGE CHARACTERISTICS Each Section

  • 30 Eco

    125 V

    AVERAGE CHARACTERISTICS Each Section

  • Ec3

    0 V

    AVERAGE CHARACTERISTICS Each Section

  • 25 b Ecl

    0 V

    AVERAGE CHARACTERISTICS Each Section

  • PlateCurrentTypical

    11 mA

    EachSection

  • ScreenCurrentTypical

    3.8 mA

    EachSection