19DLP4 — 19-Inch Cathode Ray Tube

The 19DLP4 is a 19-inch cathode ray tube (CRT) designed for television display applications. It features a 114-degree diagonal deflection angle, electrostatic focusing, and magnetic deflection. The tube utilizes a straight electron gun that does not require an ion trap magnet. It is equipped with an aluminized P4 phosphor screen, providing high brightness and a light transmittance of approximately 49% at the center of the screen.

Mechanical and Optical Characteristics

The 19DLP4 is constructed with a rectangular glass bulb designated as EIA J-149-F1. It has a short neck length of 4 3/8 ± 1/8 inches, contributing to a compact overall length of 11 5/8 ± 1/4 inches. The physical dimensions of the tube are:

• Greatest Diagonal: 18 5/8 ± 1/8 inches
• Greatest Width: 16 13/32 ± 1/8 inches
• Greatest Height: 13 11/32 ± 1/8 inches

The tube features approximate deflection angles of 102° horizontally, 85° vertically, and 114° diagonally. The minimum useful projected screen area is 172 square inches, with the following minimum dimensions:

• Diagonal: 17 9/16 inches
• Horizontal: 15 1/8 inches
• Vertical: 12 inches

The screen is coated with an aluminized P4 phosphor, which is optimized for television display service. The light transmittance at the center of the faceplate is approximately 49%.

For safety, a shatter-proof cover is recommended over the tube face to protect against potential implosion and X-ray exposure.

Electrical Connections and Basing

The 19DLP4 uses a small button neo-eightar 7-pin base with a JEDEC B7-208 designation. The electrical pinout is configured according to the JEDEC 8HR basing diagram. The high-voltage anode connection (Ultor) is made via a recessed small cavity cap (JEDEC J1-21) located on the bulb. This Ultor terminal is aligned with pin position #4 within a tolerance of ±30°.

The pin connections are assigned as follows:

• Pin 1: Heater
• Pin 2: Grid No. 1
• Pin 3: Grid No. 2
• Pin 4: Grid No. 4 (Focusing Electrode)
• Pin 6: Grid No. 1
• Pin 7: Cathode
• Pin 8: Heater
• Cap: Ultor (comprising Grid No. 3, Grid No. 5, and Collector)
• External Coating (C): External conductive coating (must be grounded)

Interelectrode Capacitances

The interelectrode capacitances of the tube are:

• Cathode to all other electrodes: approximately 5 pF
• Grid No. 1 to all other electrodes: approximately 6 pF
• External conductive coating to Anode: 1000 pF minimum, 1500 pF maximum

The external conductive coating must be properly grounded to the receiver chassis to act as a filter capacitor in conjunction with the internal anode coating.

Heater Ratings

The heater is designed for operation under the Design-Maximum System:

• Nominal Heater Voltage: 6.3 V
• Heater Voltage Range: 5.8 V (minimum) to 6.9 V (maximum)
• Heater Current: 600 ± 30 mA at 6.3 V
• Heater Warm-up Time: 11 seconds

Design-Maximum Ratings

The following ratings are established under the Design-Maximum System. Unless otherwise specified, all voltages are positive with respect to Grid No. 1:

• Anode Voltage: 10,000 V (minimum) to 20,000 V (maximum)
• Grid No. 4 (Focusing Electrode) Voltage: -500 V to +1100 V
• Grid No. 2 Voltage: 25 V (minimum) to 60 V (maximum)
• Cathode Voltage:
  • Maximum Negative DC Value: 0 V
  • Maximum Negative Peak Value: 2 V
  • Maximum Positive DC Value: 100 V
  • Maximum Positive Peak Value: 150 V
• Heater-Cathode Voltage:
  • Heater negative with respect to cathode (during warm-up ≤ 15 seconds): 450 V maximum
  • Heater negative with respect to cathode (after warm-up): 200 V maximum
  • Heater positive with respect to cathode: 200 V maximum
• Maximum Grid No. 1 Circuit Resistance: 1.5 Megohms

Typical Operating Conditions (Cathode Drive Service)

In typical cathode drive service, voltages are specified positive with respect to Grid No. 1:

• Anode Voltage: 16,000 V DC
• Grid No. 4 (Focusing Electrode) Voltage: 250 V DC (with satisfactory focus obtainable over a range of 0 to +400 V DC)
• Grid No. 2 Voltage: 50 V DC
• Cathode Voltage (for visual extinction of focused raster): 35 to 55 V DC

Technical Summary

The 19DLP4 is a 19-inch, 114-degree deflection cathode ray tube featuring electrostatic focus and magnetic deflection. It utilizes a straight electron gun, eliminating the need for an external ion trap magnet. Operating with a typical anode voltage of 16,000 V and a 6.3 V, 600 mA heater, the tube provides a bright, high-resolution display on its aluminized P4 phosphor screen. Its compact physical envelope (J-149-F1 bulb, 11 5/8 inches overall length) and standard 8HR basing make it a highly integrated component for television receiver designs. Proper grounding of the external conductive coating and the installation of a protective faceplate cover are required safety and operational practices.