Voltage Dual Triode Pentode ·Pentode-Triode-Triode
11CA11
Multifunction Compactron combining a high-gain frame-grid video pentode with two high-mu, high-transconductance triodes for television receiver signal processing.
- Sections
- 3
- Base
- -
- Socket code
- B12C
- Base pins
- 12
- Nominal heater
- 10.7 V / 600 mA
Description
11CA11 — Dissimilar-Double-Triode Pentode Compactron
A multifunction compactron containing a high-gain, frame-grid video amplifier pentode and two high-mu, high-transconductance triodes designed for cathode follower and video amplifier applications in color television receivers.
Overview
The 11CA11 is a specialized, multi-unit vacuum tube utilizing compactron construction. It integrates three distinct active sections within a single T-9 glass envelope: a high-gain, frame-grid pentode designed for video amplification, and two dissimilar high-mu triodes optimized for cathode follower and video amplifier duties.
The 11CA11 is designed primarily for use in color television receivers. Except for its heater characteristics and ratings, the 11CA11 is electrically and physically identical to the 6CA11.
Construction, Physical Specifications, and Basing
The tube features a T-9 glass bulb envelope with a 12-pin compactron base designated E12-70. The internal elements utilize coated unipotential cathodes. The physical dimensions of the device are defined by the 9-58 outline:
- Maximum Diameter: 1.188 inches
- Maximum Seated Height: 2.000 inches
- Maximum Overall Height: 2.375 inches
Its pin connections are arranged according to the 12HN basing diagram.
Heater Characteristics and Ratings
The 11CA11 heater is designed for series-string or controlled-supply operation, featuring a controlled warm-up time to ensure reliable performance in television receiver circuits.
| Heater Parameter | Value |
|---|---|
| Heater Voltage (AC or DC) | 10.7 Volts |
| Heater Current | 0.6 ± 0.04 Amperes |
| Average Heater Warm-up Time | 11 Seconds |
The average heater warm-up time is defined as the time required for the voltage across the heater to reach 80 percent of its bogey value after applying four times the bogey heater voltage to a circuit consisting of the tube heater in series with a resistance equal to three times the bogey heater voltage divided by the bogey heater current. This is in contrast to the related 6CA11, which operates at a nominal heater voltage of 6.3 Volts and a current of 1020 mA, without a specified controlled warm-up time.
The heater-to-cathode insulation is rated to withstand the following maximum voltages:
- Heater Negative with Respect to Cathode (Total DC and Peak): 200 Volts
- Heater Positive with Respect to Cathode (DC Component): 100 Volts
- Heater Positive with Respect to Cathode (Total DC and Peak): 200 Volts
Electrical Characteristics and Typical Operation
The three independent sections of the 11CA11 exhibit distinct electrical characteristics. Typical operating parameters for each section are detailed below.
Triode Section 1
Triode Section 1 is a high-mu triode operating typically under the following conditions:
- Plate Voltage: 200 Volts
- Cathode Bias Resistor: 270 Ohms
- Grid Voltage: -2.0 Volts
- Amplification Factor: 63
- Plate Resistance (Approximate): 10,000 Ohms
- Transconductance: 6,300 µmhos
- Plate Current: 7.1 mA
- Approximate Grid Voltage (for Ib = 100 µA): -6.3 Volts
Triode Section 2
Triode Section 2 is a high-mu triode with slightly different characteristics:
- Plate Voltage: 200 Volts
- Cathode Bias Resistor: 270 Ohms
- Grid Voltage: -2.0 Volts
- Amplification Factor: 69
- Plate Resistance (Approximate): 12,400 Ohms
- Transconductance: 5,500 µmhos
- Plate Current: 7.1 mA
- Approximate Grid Voltage (for Ib = 100 µA): -5.5 Volts
Pentode Section
The pentode section is a high-gain, frame-grid design. Its typical operation is characterized at two distinct operating points:
| Parameter | Operating Point A | Operating Point B |
|---|---|---|
| Plate Voltage | 40 Volts | 200 Volts |
| Screen Voltage | 120 Volts | 120 Volts |
| Grid No. 1 Voltage | 0 Volts | — |
| Cathode Bias Resistor | — | 65 Ohms |
| Plate Resistance (Approx.) | — | 490,000 Ohms |
| Transconductance | — | 21,200 µmhos |
| Plate Current | 68 mA | 27.5 mA |
| Screen Current | 17.6 mA | 4.9 mA |
| Approx. Grid No. 1 Voltage (for Ib = 100 µA) | — | -5.0 Volts |
Design Maximum Ratings
Under the Design Maximum Rating System, the maximum allowable limits for each section are as follows:
Triode Sections (No. 1 and No. 2)
- Plate Voltage (Maximum): 330 Volts
- Positive DC Grid Voltage (Maximum): 0 Volts
- Plate Dissipation (Maximum, per section): 1.5 Watts
- Grid Circuit Resistance (Maximum):
- With Fixed Bias: 0.5 Megohm
- With Cathode Bias: 1.0 Megohm
Pentode Section
- Plate Voltage (Maximum): 330 Volts
- Screen-Supply Voltage (Maximum): 330 Volts
- Positive DC Grid No. 1 Voltage (Maximum): 0 Volts
- Plate Dissipation (Maximum): 5.0 Watts
- Screen Dissipation (Maximum): 1.0 Watt
- Grid No. 1 Circuit Resistance (Maximum):
- With Fixed Bias: 10,000 Ohms
- With Cathode Bias: 10,000 Ohms
Direct Interelectrode Capacitances
These capacitances are measured without an external shield. The internal connections and shielding are reflected in the measurement conditions:
Triode Section 1
- Grid to Plate: 2.7 pF
- Input (1Tg to [1Tk + 2Tk + Pk + Pg3 + h + IS]): 4.7 pF
- Output (1Tp to [1Tk + 2Tk + Pk + Pg3 + h + IS]): 4.0 pF
Triode Section 2
- Grid to Plate: 2.1 pF
- Input (2Tg to [2Tk + Pk + Pg3 + h + IS]): 2.8 pF
- Output (2Tp to [2Tk + Pk + Pg3 + h + IS]): 2.0 pF
Pentode Section
- Grid No. 1 to Plate: 0.13 pF
- Input (Pg1 to [2Tk + Pk + Pg2 + Pg3 + h + IS]): 12.3 pF
- Output (Pp to [2Tk + Pk + Pg2 + Pg3 + h + IS]): 4.6 pF
Inter-Section Coupling
- Pentode Plate to Triode Plate (Section 2) (Maximum): 0.045 pF
- Triode Plate (Section 1) to Triode Plate (Section 2) (Maximum): 0.100 pF
Technical Summary
The 11CA11 is a twelve-pin compactron containing two high-mu triodes and a high-gain frame-grid pentode in a single T-9 envelope. Operating with a 10.7 V, 0.6 A heater with a controlled 11-second warm-up time, it is optimized for series-string color television designs, serving as a combined video amplifier and cathode follower. Its design maximum ratings allow up to 330 V on the plates of all sections, with the pentode capable of dissipating up to 5.0 W and the triodes up to 1.5 W each.
Socket description
Duodecar 12-contact
General specifications
Tube and section characteristics
Properties common to every published source and operating point.
Heater and base
- Base
- -
- Socket code
- B12C
- Base pins
- 12
- Nominal heater voltage
- 10.7 V
- Nominal heater current
- 600 mA
- Parallel heater voltage
- -
- Parallel heater current
- -
- Series capable
- No
Terminal pinout
Electrical assignments shared by every tube using this base designation.
No verified pinout is recorded for this base designation.
Section ratings
3 physical sections, each with unique specifications.
Section 1
Pentode
- Plate resistance
- 490000 Ω
- Transconductance
- 0.0212 S
- Max plate voltage
- 330 V
- Max plate dissipation
- 5 W
- Max screen dissipation
- 1 W
Sylvania 11CA11 high-gain frame-grid video-amplifier pentode within Compactron dual-triode-pentode. Maximum plate and screen supply 330 V; plate dissipation 5 W and screen dissipation 1 W, subject to conditional screen rating chart. Typical plate 200 V, screen 120 V, cathode resistor 65 ohms, gm 21.2 mA/V and approximate plate resistance 490 kΩ. Contains two dissimilar triode sections for cathode follower/video amplification. GE states 11CA11 identical to 6CA11 electrically except 10.7 V 0.6 A heater rating. Sylvania basing 12HN; existing database socket code not changed pending separate base-code reconciliation.
Section 2
Triode
- Plate resistance
- 10000 Ω
- Transconductance
- 0.0063 S
- Amplification factor
- 63
- Max plate voltage
- 330 V
- Max plate dissipation
- 1.5 W
Sylvania 11CA11 first of two physically distinct dissimilar high-mu triodes. Max plate voltage 330 V, plate dissipation 1.5 W. Typical plate 200 V, cathode bias resistor 270 ohms, grid bias -2 V, plate current 7.1 mA; mu 63, gm 6.3 mA/V, plate resistance 10 kΩ. Second triode differs electrically (mu 69, gm 5.5 mA/V, rp 12.4 kΩ), so do not compress or duplicate section constants. 10.7 V 0.6 A heater; Sylvania basing 12HN, existing socket code retained.
Section 3
Triode
- Plate resistance
- 12400 Ω
- Transconductance
- 0.0055 S
- Amplification factor
- 69
- Max plate voltage
- 330 V
- Max plate dissipation
- 1.5 W
Sylvania 11CA11 second physical triode, electrically dissimilar to first. Maximum plate voltage 330 V and dissipation 1.5 W. Typical plate 200 V, 270-ohm cathode bias resistor, plate current 7.1 mA, amplification factor 69, gm 5.5 mA/V, plate resistance approximately 12.4 kΩ. The other triode has mu 63, gm 6.3 mA/V, plate resistance 10 kΩ. Compactron combines both with video-amplifier pentode. Sylvania lists basing 12HN, retained database socket pending reconciliation.
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.