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Specialized - Cathode Ray ·CathodeRay

19QP4

P4 monochrome television picture tube using magnetic deflection and high-voltage direct-view operation; manufacturer documentation for 19QP4 provides focusing, deflection, and beam-control characteristics for television picture service.

Directly heatedCold cathodeCommon cathodeDissimilarSpecialized
Sections
1
Base
12L
Socket code
DUODECAL6
Base pins
6
Nominal heater
5.3 V / 600 mA

Description

19QP4 — Cathode-Ray Picture Tube

The 19QP4 is a direct-view rectangular glass cathode-ray picture tube designed for television display applications. It features a grey filter faceplate, a unipotential cathode, low-voltage electrostatic focusing, and magnetic deflection. The tube is designed to operate with an external single-field ion trap and incorporates an external conductive coating that serves as an electrical component in conjunction with the anode.

Mechanical and Optical Design

The 19QP4 is constructed with a rectangular glass envelope. Its physical dimensions and screen characteristics are highly specified to ensure proper mounting and display area:

  • Overall Length: 21 1/8 ± 3/8 inches
  • Greatest Bulb Diagonal: 18 5/8 ± 1/8 inches
  • Greatest Bulb Width: 17 1/16 ± 1/8 inches
  • Minimum Useful Screen Diagonal: 17 21/32 inches
  • Minimum Useful Screen Width: 16 inches
  • Minimum Useful Screen Height: 12 inches
  • Raster Size: 12 x 16 inches

The screen utilizes Phosphor No. 4, which produces a white fluorescent color and a white phosphorescent color with medium persistence. Deflection is achieved magnetically, with approximate deflection angles of:

  • Horizontal Deflection Angle: 66 degrees
  • Diagonal Deflection Angle: 70 degrees

For electrical connection to the high-voltage anode, the tube features a recessed small cavity cap (J1-21) located on the bulb. This contact is aligned with pin position #6 within a tolerance of ± 10 degrees. The base is a small shell duodecal 6-pin configuration (B6-63) with a 12L basing arrangement.

Electrical Connections and Capacitances

The bottom view of the small shell duodecal base provides the following pin connections:

Pin NumberConnection
Pin 1Heater
Pin 2Grid No. 1
Pin 6Grid No. 4
Pin 10Grid No. 2
Pin 11Cathode
Pin 12Heater
Anode CapGrid No. 3 / Anode

The direct interelectrode capacitances of the tube are approximately:

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

The external conductive coating, when combined with the internal anode coating, forms a capacitor that can be utilized for high-voltage filtering in the television receiver power supply.

Maximum Ratings

The following maximum ratings are established under the Design Center system:

  • Heater Voltage: 6.3 Volts
  • Heater Current: 0.6 Ampere
  • Maximum DC Anode Voltage: 18,000 Volts
  • Maximum DC Grid No. 4 Voltage: 500 Volts
  • Maximum DC Grid No. 2 Voltage: 410 Volts
  • Maximum Grid No. 1 Voltage:
    • DC Negative-bias value: 125 Volts
    • DC Positive-bias value: 0 Volts
    • Positive-peak value: 2 Volts
  • Maximum DC Peak Heater-Cathode Voltage:
    • Heater negative with respect to cathode during warm-up period (not to exceed 15 seconds): 410 Volts
    • Heater negative with respect to cathode after equipment warm-up period: 150 Volts
    • Heater positive with respect to cathode: 150 Volts

The maximum allowable circuit resistance for Grid No. 1 is 1.5 Megohms.

Typical Operating Conditions

Under typical operating conditions, the 19QP4 is configured with the following electrical parameters:

  • DC Anode Voltage: 12,000 Volts
  • DC Grid No. 4 Voltage: -50 to +350 Volts (measured with the anode current set to 100 µA)
  • DC Grid No. 2 Voltage: 300 Volts
  • DC Grid No. 1 Voltage: -33 to -77 Volts (required for visual extinction of the undeflected focused spot)
  • DC Ion Trap Current: Approximately 75 ± 50% mA when using a Standard Coil No. 111

The electrostatic focusing system utilizes Grid No. 4 to control focus, allowing adjustment within the specified range to achieve optimal spot sharpness. The external single-field ion trap requires a standard coil operating at the specified current to prevent ion burn on the phosphor screen.

Technical Summary

The 19QP4 is a rectangular glass cathode-ray picture tube featuring a 12" x 16" raster size, low-voltage electrostatic focus, and magnetic deflection. Operating with a 6.3 V, 0.6 A heater, it is designed for television applications requiring a medium-persistence white display (Phosphor No. 4). Its design incorporates an external single-field ion trap and an external conductive coating to assist in anode filtering. With a maximum design-center anode rating of 18,000 V and typical operation at 12,000 V, the 19QP4 provides a standardized display solution for television receivers of its era.

Socket description

Small-shell Duodecal 6-contact CRT base

General specifications

Tube and section characteristics

Properties common to every published source and operating point.

Heater and base

Base
12L
Socket code
DUODECAL6
Base pins
6
Nominal heater voltage
5.3 V
Nominal heater current
600 mA
Parallel heater voltage
-
Parallel heater current
-
Series capable
No

12L - 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 plate voltage
18000 V
Max screen voltage
500 V

CRT ratings, operating conditions, capacitances, and optical/deflection data retained below as 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

1961 Tung Sol

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Other

  • DC anode voltage

    12000 V

    Typical

Characteristic

  • Horizontal deflection angle

    66 degree

    Approximate

Capacitance

  • Cathode to all other electrodes

    5 pF

Data set 02

1966 Tung Sol Electronic Tubes 4 of 4

Published operating points and test conditions from this source.

SECTION 1

Cathode Ray

Characteristics

  • HEATER VOLTAGE

    5.3 V

    Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.

  • HEATER POSITIVE WITH RESPECT TO CATHODE

    15 V

    Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.

  • DC ANODE VOLTAGE

    12 V

    Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.

  • DC GRID #4 VOLTAGE A — value 1

    4 V

    Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.

  • DC GRID #4 VOLTAGE A — value 2

    -5 V

    Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.

  • DC GRID #4 VOLTAGE A — value 3

    350 V

    Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.

  • DC GRID #2 VOLTAGE — value 1

    2 V

    Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.

  • DC GRID #2 VOLTAGE — value 2

    3 V

    Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.

  • DC ION TRAP CURRENT STANDARD COIL #111 (APPROX.J — value 1

    111 mA

    Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.

  • DC ION TRAP CURRENT STANDARD COIL #111 (APPROX.J — value 2

    75 mA

    Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.

  • DC ION TRAP CURRENT STANDARD COIL #111 (APPROX.J — value 3

    50 mA

    Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.

Other

  • MAXIMUM DC ANODE VOLTAGE

    1 V

    Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.

  • MAXIMUM DC GRID #4 VOLTAGE — value 1

    4 V

    Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.

  • MAXIMUM DC GRID #4 VOLTAGE — value 2

    5 V

    Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.

  • MAXIMUM DC GRID #2 VOLTAGE — value 1

    2 V

    Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.

  • MAXIMUM DC GRID #2 VOLTAGE — value 2

    41 V

    Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.

  • MAXIMUM GRID #1 VOLTAGE

    1 V

    Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.

  • MAXIMUM GRID #1 CIRCUIT RESISTANCE — value 1

    1 mA

    Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.

  • MAXIMUM GRID #1 CIRCUIT RESISTANCE — value 2

    1.5 mA

    Published CRT datasheet value; multiple values on a row correspond to separate source-table conditions or limits.