19BVP4 — Television Picture Tube

A rectangular glass television picture tube featuring a 114-degree magnetic deflection angle, low-voltage electrostatic focusing, and an aluminized P4 phosphor screen.

Overview

The 19BVP4 is a rectangular glass television picture tube designed for use in television receivers. It features a spherical faceplate made of gray filter glass, an aluminized screen utilizing P4 phosphor, and a short neck design. The tube employs low-voltage electrostatic focusing and magnetic deflection, with a nominal diagonal deflection angle of 114 degrees. It does not require an ion trap. An external conductive coating is applied to the bulb, which forms a supplementary filter capacitor when grounded.

Mechanical and Physical Construction

The 19BVP4 is constructed with a J149A1 glass bulb and a short neck to minimize the overall depth of the television cabinet. The physical dimensions and mechanical specifications of the tube are as follows:

• Overall Length: 11-3/4  1/4 inches
• Neck Length: 4-1/2  1/8 inches
• Neck Diameter: Maximum of 1.168 inches at the splice
• Weight: 13-1/2 lbs
• Greatest Dimensions:
  • Diagonal: 18-5/8  1/8 inches
  • Width: 16-13/32  1/8 inches
  • Height: 13-11/32  1/8 inches
• Minimum Useful Screen Dimensions (Projected):
  • Diagonal: 17-9/16 inches
  • Horizontal: 15-1/8 inches
  • Vertical: 12 inches
  • Minimum Useful Projected Area: 172 square inches

The screen size is 12 inches by 15-1/8 inches. The faceplate is spherical and made of gray filter glass with a light transmittance of approximately 78% at the center. The screen uses an aluminized P4 phosphor.

The tube uses a B7-208 wafer base, whose perimeter fits inside a 1-3/4 inch diameter circle. To prevent mechanical stress on the tube neck, the mating socket must have flexible leads to avoid lateral strains. The anode connection is made via a J1-21 recessed small cavity cap on the bulb, which has an angular tolerance of 30 about the tube axis relative to the alignment of pin 4.

Heater and Electrical Connections

The 19BVP4 is equipped with a heater designed for series or parallel operation.

Heater Ratings

• Heater Voltage: 6.3 V
• Heater Current: 600  5% mA
• Heater Warm-up Time: 11 seconds

The heater warm-up time is defined as the time required for the heater voltage to reach 80% of its rated value when four times the rated voltage is applied to the heater in series with a resistance equal to three times the rated voltage divided by the rated current.

Pinout and Basing (8HR)

The tube utilizes the 8HR basing configuration. The pin connections, viewed from the bottom of the base, are as follows:

Interelectrode Capacitances

• Cathode to all other electrodes: Approximately 5 pF
• Grid 1 to all other electrodes: Approximately 6 pF
• External Conductive Coating to Anode: Maximum 1500 pF, Minimum 1000 pF

The external conductive coating must be grounded, as it forms a supplementary high-voltage filter capacitor in conjunction with the internal anode coating.

Deflection and Focusing

The 19BVP4 utilizes magnetic deflection and low-voltage electrostatic focusing. The approximate deflection angles are:

• Diagonal: 114
• Horizontal: 103
• Vertical: 86

The yoke reference line is determined by JEDEC Reference-Line Gauge No. 126 seated on the funnel. If a permanent magnet (PM) centering magnet is used, its field strength must be between 0 and 8 gauss, and it must not extend more than 2-1/8 inches from the reference line.

Ratings and Operating Conditions

The ratings of the 19BVP4 are established under the Design-Maximum System. All voltages are specified as positive with respect to Grid 1, unless otherwise noted.

Design-Maximum Ratings

• Anode Voltage: Maximum 23,500 V, Minimum 12,000 V. Operation below 12,000 V is not recommended because of the resulting decrease in picture brilliance and definition.
• Grid 4 Voltage (Focusing Electrode): Maximum +1100 V, Minimum -550 V.
• Grid 2 Voltage: Maximum 700 V.
• Cathode Voltage:
  • Maximum Negative DC Value: 0 V
  • Maximum Negative Peak Value: 2 V
  • Maximum Positive DC Value: 154 V
  • Maximum Positive Peak Value: 220 V
• Heater-Cathode Voltage:
  • Heater negative with respect to cathode:
    • During warm-up period (≤ 15 seconds): Maximum 450 V
    • After warm-up period: Maximum 200 V
  • Heater positive with respect to cathode: Maximum 200 V

Typical Operating Conditions (Cathode Drive Service)

In typical cathode drive service, the voltages are referenced positive with respect to Grid 1:

• Anode Voltage: 20,000 V DC
• Grid 4 Voltage (Focusing Electrode): 250 V DC
• Grid 2 Voltage: 500 V DC. To maintain proper resolution, Grid 2 voltage should not be set below 300 V.
• Cathode Voltage for Raster Cutoff: 45 to 95 V DC

Limiting Circuit Values

• Maximum Grid 1 Circuit Resistance: 1.5 MΩ
• Minimum Grid 2 and Grid 4 Circuit Resistance: 10,000 Ω. A protective resistance of at least this value is recommended in these circuits to prevent damage from momentary internal arcs.

Safety and Installation Notes

Because the 19BVP4 operates at high voltages, safety precautions must be observed:

• X-Ray Warning: When the tube is operated at anode voltages above 16 kV, soft X-ray radiation may be produced. Appropriate shielding may be required to protect users from prolonged exposure.
• Handling: The tube weighs 13-1/2 lbs and has a large evacuated glass envelope. It must be handled with care to avoid implosion.

Technical Summary

The 19BVP4 is a 114-degree magnetic deflection, low-voltage electrostatic focus television picture tube. It features a rectangular glass envelope with a spherical gray filter glass faceplate, an aluminized P4 phosphor screen, and a short neck. Operating with a 6.3 V, 600 mA heater, it is designed for cathode drive service with a typical anode voltage of 20,000 V. The tube incorporates an external conductive coating that acts as a supplementary filter capacitor when grounded, and utilizes an 8HR basing configuration on a B7-208 wafer base.