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Specialized - Cathode Ray ·CathodeRay

11GP4

Eleven-inch P4 cathode-ray picture tube with magnetic deflection and a broad direct-view screen. RCA data show high-voltage anode operation up to about 15 kV together with normal control-grid and focusing-electrode requirements.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized
Sections
1
Base
-
Socket code
-
Base pins
7
Nominal heater
6.9 V / 20 A

Description

11GP4 Picture Tube

The 11GP4 is a filled-rim picture tube designed for television display applications. It features a 110-degree diagonal magnetic deflection angle, an intermediate-grid-No.2 voltage gun design, and a rectangular screen. The tube incorporates an aluminized P4-sulfide phosphor screen and a filterglass faceplate to optimize optical performance.

Optical and Mechanical Characteristics

The 11GP4 is constructed with a filled-rim design that includes integral implosion protection hardware. The faceplate is made of filterglass with an approximate light transmission of 52% at the center. The optical system utilizes an aluminized P4-sulfide phosphor. The electron gun is designed to operate without requiring an external ion-trap magnet.

Mechanical Dimensions and Deflection Angles

The physical envelope of the 11GP4 is compact, featuring a short neck and a wide deflection angle to minimize cabinet depth. The mechanical specifications include:

  • Weight: Approximately 5 lb
  • Overall Length: 8.785 ± 0.250 inches
  • Neck Length: 4.125 ± 0.125 inches
  • Projected Area of Screen: 60 square inches
  • Minimum Screen Dimensions:
    • Diagonal: 10.250 inches
    • Greatest Width: 9.000 inches
    • Greatest Height: 7.062 inches
  • Deflection Angles:
    • Diagonal: 110°
    • Horizontal: 99°
    • Vertical: 82°

Calculated Screen Aspect Ratio: Based on the minimum screen width of 9.000 inches and greatest height of 7.062 inches, the minimum screen aspect ratio is calculated as 9.000 / 7.062 ≈ 1.274.

External Coating and Grounding

The tube features an external conductive coating of the regular-band type. This coating forms a capacitor with the internal anode structure. The capacitance of this system is rated between a minimum of 500 pF and a maximum of 750 pF. A designated contact area near the reference line is provided for grounding the external coating.

Electrical Connections and Pinout

The 11GP4 uses a JEDEC No. B7-208 Small-Button Neoeightar 7-pin base (Arrangement 1) and a JEDEC No. J1-21 recessed small cavity cap for the high-voltage anode connection. The reference line of the neck is determined by the JEDEC No. G-126 gauge.

The terminal connections, viewed from the bottom of the base, are assigned as follows:

Pin NumberConnection
Pin 1Heater
Pin 2Grid No.1
Pin 3Grid No.2
Pin 4Grid No.4
Pin 6Grid No.1
Pin 7Cathode
Pin 8Heater
CapAnode (Grid No.3, Grid No.5, Screen, Collector)
C (Coating)External Conductive Coating

Note that Grid No.1 is connected to both Pin 2 and Pin 6.

Interelectrode Capacitances

The direct interelectrode capacitances of the tube, measured without external shielding, are:

  • Cathode to all other electrodes: 5 pF
  • Grid No.1 to all other electrodes: 6 pF
  • External conductive coating to anode: 500 pF (minimum) to 750 pF (maximum)

Heater and Warm-Up Characteristics

The heater is designed for operation at a nominal voltage of 6.3 V.

Heater ParameterValue
Nominal Voltage6.3 V
Current450 ± 20 mA
Average Warm-Up Time11 seconds
Voltage Range (Design-Maximum)5.7 V to 6.9 V

Calculated Nominal Heater Power: Using the nominal voltage of 6.3 V and nominal current of 0.45 A, the nominal power consumption of the heater is calculated as 6.3 V × 0.45 A = 2.835 W.

Maximum and Minimum Ratings

The following design-maximum ratings define the operating envelopes of the 11GP4. All voltages, unless otherwise specified, are positive with respect to the cathode.

Electrode Voltages

  • Anode Voltage: 8,000 V minimum to 15,000 V maximum
  • Grid-No.4 (Focusing Electrode) Voltage:
    • Positive value: 1,100 V maximum
    • Negative value: 550 V maximum
  • Grid-No.2 Voltage: 100 V minimum to 250 V maximum
  • Cathode Voltage:
    • Negative peak value: 220 V maximum
    • Negative bias value: 155 V maximum
    • Positive bias value: 0 V maximum
    • Positive peak value: 2 V maximum

Peak Heater-Cathode Voltage

The insulation between the heater and the cathode is rated to withstand specific peak voltages depending on the polarity and the operating state of the equipment:

  • Heater negative with respect to cathode:
    • During equipment warm-up period (≤ 15 seconds): 450 V maximum
    • After equipment warm-up period: 300 V maximum
  • Heater positive with respect to cathode:
    • Combined AC and DC voltage: 200 V maximum
    • DC component: 100 V maximum

Maximum Circuit Values

  • Grid-No.1 Circuit Resistance: 1.5 MΩ maximum

Typical Operating Conditions (Cathode-Drive Service)

In typical cathode-drive service, the operating voltages are referenced positive with respect to Grid No.1:

  • Anode Voltage: 11,000 V
  • Grid-No.4 Voltage: 0 V
  • Grid-No.2 Voltage: 150 V
  • Cathode Voltage (for visual extinction of focused raster): 31 V to 49 V

Under these conditions, focusing is achieved with Grid No.4 at ground potential (0 V), and the video signal is applied to the cathode, with raster cutoff occurring within the 31 V to 49 V range.

Technical Summary

The 11GP4 is a compact, 110-degree magnetic deflection picture tube featuring a filled-rim design with integrated implosion protection. It employs a 6.3 V, 450 mA heater with a rapid 11-second average warm-up time. Utilizing a P4-sulfide aluminized phosphor screen and a 52% transmission filterglass faceplate, it provides a 60-square-inch projected screen area. The tube is characterized by its intermediate-grid-No.2 gun design, which operates without an ion-trap magnet, and is optimized for cathode-drive applications with an anode voltage rating up to 15,000 V and a typical operating anode voltage of 11,000 V.

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
-
Socket code
-
Base pins
7
Nominal heater voltage
6.9 V
Nominal heater current
20 A
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

1 physical section, each with unique specifications.

Section 1

Cathode Ray

X-ray radiationInterelectrode capacitances
Max screen voltage
250 V

CRT-specific ratings, operating conditions, capacitances, focus/deflection, cutoff, optical, and screen data are retained in section parameters.

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

1971 RCA HB3 Binder 1 of 7

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Characteristics

  • Grid No.l to all other electrodes

    6 pF

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • External conductive coating to anodes — published value 1

    500 mA

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • External conductive coating to anodes — published value 2

    750 mA

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Heater Current at 6.3 V — published value 1

    6.3 mA

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Heater Current at 6.3 V — published value 2

    450 mA

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Heater Current at 6.3 V — published value 3

    20 mA

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Light transmission at center (Approx.)

    52

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Projected Area of Screen

    60

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Anode Voltage — published value 1

    8000 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Anode Voltage — published value 2

    15000 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Grid-No.2 Voltage — published value 1

    100 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Grid-No.2 Voltage — published value 2

    250 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Heater Voltage — published value 1

    5.7 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Heater Voltage — published value 2

    6.9 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Combined AC & DC voltage

    200 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Anode Voltage — published value 1

    1 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Anode Voltage — published value 2

    1000 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Grid-No.4 Voltage

    0 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Grid-No.2 Voltage

    150 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Cathode Voltage — published value 1

    31 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Cathode Voltage — published value 2

    49 V

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.

  • Grid-No. l Circuit Resistance

    1.5 mA

    Published CRT datasheet value; multiple numbers on one source row represent its separate limits or operating conditions.