19DSP4 — Black-and-White Rectangular Picture Tube

The 19DSP4 is a rectangular glass picture tube designed for black-and-white television receivers. It features Pan-O-Ply integral implosion protection, which utilizes a formed rim band and a welded tension band around the periphery of the tube panel. This design eliminates the need for a separate safety-glass window or an integral protective window. The tube incorporates an aluminized screen with nearly straight sides and slightly rounded corners, a low-voltage electrostatic focus system, and a 114-degree magnetic deflection angle. Its electron gun is designed to operate without an ion-trap magnet and features a low Grid No. 2 voltage configuration optimized for cathode-drive operation.

Mechanical and Optical Characteristics

The 19DSP4 is constructed with a J149 F1 glass bulb and a filterglass faceplate. The faceplate provides a light transmission of approximately 48% to 49% at the center. The screen utilizes a sulfide-type, aluminized P4 phosphor.

Physical Dimensions and Weight

• Overall Length: 11.625 ± 0.250 inches
• Neck Length: 4.375 ± 0.125 inches
• Diagonal Dimension: 18.732 ± 0.100 inches
• Greatest Width: 16.514 ± 0.100 inches
• Greatest Height: 13.473 ± 0.100 inches
• Projected Screen Area: 172 square inches
• Weight: Approximately 15 to 15.5 lbs

The tube features a Regular-Band type external conductive coating. The contact area for grounding is located near the Reference Line. Both the external coating and the integral implosion protection hardware must be connected to a common ground.

Electrical Connections and Basing

The 19DSP4 uses a Small-Button Neoeightar 7-Pin base (JEDEC No. B7-208, Arrangement 1) with an 8HR basing designation. High-voltage connection to the anode is made via a Recessed Small Cavity cap (JEDEC No. J1-21).

Pin Configuration (Bottom View)

Direct Interelectrode Capacitances

• Cathode to all other electrodes: 5 pF
• Grid No. 1 to all other electrodes: 6 pF
• External conductive coating to anode: 1000 to 1250 pF minimum; 1500 to 1750 pF maximum

Heater and Filament Ratings

The heater is designed for a typical operating voltage of 6.3 V, with a design-maximum range of 5.7 V to 6.9 V.

The average heater warm-up time of 11 seconds is determined using a specific test circuit. In this test, the voltage across the heater terminals increases from zero to 0.8 of the rated voltage, where the supply voltage is four times the rated heater voltage ($4 \times E_f$) and the series resistance is calculated as: $\text{Series Resistance } (R) = \frac{3 \times E_f}{I_f}$

Maximum Ratings and Operating Conditions

The following limits are specified under the Design-Maximum Rating System. Unless otherwise noted, all voltage values are positive with respect to Grid No. 1.

Design-Maximum Ratings

• Anode Voltage: 10,000 V minimum to 20,000 V maximum
• Grid-No. 4 (Focusing) Voltage:
  • Positive value: 1250 V maximum
  • Negative value: 400 V maximum
• Grid-No. 2 Voltage: 40 V minimum to 70 V maximum
• Cathode Voltage:
  • Negative peak value: 2 V maximum
  • Negative bias value: 0 V maximum
  • Positive bias value: 100 V maximum
  • Positive peak value: 150 V maximum
• Heater Voltage: 5.7 V minimum to 6.9 V maximum
• Peak Heater-Cathode Voltage:
  • Heater negative with respect to cathode: 450 V maximum during equipment warm-up (first 15 seconds or less); 300 V maximum after the warm-up period.
  • Heater positive with respect to cathode: 200 V maximum (combined AC and DC); 100 V maximum (DC component).
• Grid-No. 1 Circuit Resistance: 1.5 MΩ maximum

Typical Cathode-Drive Operating Conditions

Under typical cathode-drive service, the operating parameters are established as follows:

• Anode Voltage: 16,000 V
• Grid-No. 4 Voltage: 100 V (The optimum focus for individual tubes ranges from -100 V to +300 V, with the combined Grid-No. 1 and video-signal voltage adjusted for a 100 µA anode current on a 10.5-inch by 14-inch pattern)
• Grid-No. 2 Voltage: 50 V
• Cathode Voltage (for visual extinction of focused raster): 32 V to 50 V
• Centering Magnet Field Strength: 0 to 8 gauss

The maximum field strength of the required adjustable centering magnet is calculated using the following relationship: $\text{Maximum Field Strength} = 8 \times \sqrt{\frac{\text{Anode Volts}}{16000}} \text{ gauss}$ The permanent magnet (PM) centering magnet should be positioned such that its distance from the reference line does not exceed 2-1/4 inches.

Raster Cutoff Characteristics

The cathode-to-Grid-No. 1 voltage required for the visual extinction of the focused raster is directly related to the Grid-No. 2-to-Grid-No. 1 voltage. This cutoff voltage increases linearly as the Grid-No. 2 voltage is increased. For example, at a Grid-No. 2 voltage of 50 V, the typical cutoff range is 32 V to 50 V. Additionally, the cutoff voltage varies directly with the anode potential, shifting by approximately 1 volt for every 1000-volt change in the Anode-to-Grid-No. 1 voltage.

Technical Summary

The 19DSP4 is a 114-degree magnetic deflection, black-and-white rectangular glass picture tube featuring Pan-O-Ply integral implosion protection. Operating with a 6.3 V, 600 mA heater, it utilizes low-voltage electrostatic focusing and does not require an external ion-trap magnet. Designed primarily for cathode-drive service, the tube operates typically at an anode voltage of 16,000 V and a Grid-No. 2 voltage of 50 V, with a raster cutoff range of 32 V to 50 V. Its mechanical design incorporates a J149 F1 bulb, a Neoeightar 7-pin base, and a grounded external conductive coating.