19DHP4 — 19-Inch Cathode-Ray Picture Tube

The 19DHP4 is a 19-inch, 114-degree banded cathode-ray picture tube designed primarily for television display applications. It features a straight electron gun that does not require an ion trap, electrostatic focusing, and a cathode-drive design optimized for a 50-volt Grid No. 2 supply.

Mechanical and Optical Specifications

The 19DHP4 is constructed with a J-149-F1 glass bulb and uses a B7-208 base with an 8HR basing configuration. The physical dimensions and screen characteristics of the tube are as follows:

Physical Dimensions

• Overall Length: 11 5/8 ± 1/4 inches
• Neck Length: 4 3/8 ± 1/8 inches
• Greatest Diagonal: 18 7/8 inches maximum
• Greatest Width: 16 11/16 inches maximum
• Greatest Height: 13 39/64 inches maximum
• Bulb Contact Alignment: The J1-21 contact aligns with pin position #4 within a tolerance of ± 30 degrees.

Screen and Optical Characteristics

• Phosphor: P4 Aluminized (JEDEC designation)
• Light Transmittance: Approximately 49% at the center of the screen
• Minimum Useful Screen Dimensions (Projected):
  • Diagonal: 17 9/16 inches
  • Horizontal: 15 1/8 inches
  • Vertical: 12 inches
  • Area: 172 square inches

Deflection Angles

• Diagonal: 114°
• Horizontal: 102°
• Vertical: 86°

Electrical Characteristics and Capacitances

The electrical parameters of the 19DHP4 include specific heater ratings and interelectrode capacitances necessary for proper circuit integration.

Heater Ratings

• Heater Voltage (Typical): 6.3 V
• Heater Voltage Range: 5.8 V (Minimum) to 6.9 V (Maximum)
• Heater Current: 600 ± 30 mA at a heater voltage of 6.3 V
• Heater Warm-up Time: 11 seconds

Direct Interelectrode Capacitances

• 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 to 1500 pF maximum

Circuit Limits

• Grid No. 1 Circuit Resistance: 1.5 Megohms maximum

Pinout and Basing Configuration

The 19DHP4 utilizes the JEDEC 8HR basing arrangement. The connections, viewed from the bottom of the base, are assigned as follows:

Maximum Ratings (Design-Maximum System)

All voltages are positive and measured with respect to Grid No. 1 unless otherwise specified.

• Anode Voltage: 20,000 V maximum, 10,000 V minimum
• Grid No. 4 (Focusing Electrode) Voltage: -500 V to +1100 V
• Grid No. 2 Voltage: 60 V maximum, 25 V minimum
• 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 period (first 15 seconds or less): 450 V maximum
    • After equipment warm-up period: 200 V maximum
  • Heater positive with respect to cathode: 200 V maximum

Typical Operating Conditions (Cathode Drive Service)

Under typical operating conditions in cathode drive service, voltages are positive and measured with respect to Grid No. 1 unless otherwise specified.

• Anode Voltage: 16,000 V DC
• Grid No. 4 Voltage (Focusing Electrode): 250 V DC (Individual tubes focus within the range of 0 V to +400 V; adjusted for 100 µA anode current on a 15 1/8" by 12" pattern)
• Grid No. 2 Voltage: 50 V DC
• Cathode Voltage: 35 V to 55 V DC (for visual extinction of the focused raster)

Technical Summary

The 19DHP4 is a 19-inch, 114-degree banded cathode-ray picture tube featuring electrostatic focus, a straight gun design requiring no ion trap, and a cathode-drive configuration. Operating with a typical anode voltage of 16,000 V and a Grid No. 2 voltage of 50 V, it provides a projected useful screen area of 172 square inches with a P4 aluminized phosphor. The tube is characterized by its 11-second heater warm-up time, standard 6.3 V heater rating, and JEDEC 8HR basing configuration.