19BNP4 — Rectangular Glass Television Picture Tube

The 19BNP4 is a 19-inch direct-viewed, rectangular glass television picture tube designed for use in television receivers. It features a spherical faceplate with a bonded shield, consisting of a gray filter glass safety plate laminated directly to the face of the tube. The tube utilizes electrostatic focusing and magnetic deflection, with an aluminized P4 phosphor screen that produces white fluorescence with short-to-medium persistence. Designed primarily for cathode-drive service, the 19BNP4 operates with a nominal 6.3 V heater and has a wide deflection angle.

Construction and Mechanical Characteristics

The 19BNP4 is constructed with a rectangular glass bulb (designated J149C) and a spherical faceplate. The faceplate incorporates a bonded shield (FP159A safety plate) made of gray filter glass, which provides a light transmittance of approximately 44%.

The screen uses an aluminized P4 phosphor, which exhibits white fluorescence and short-to-medium persistence. To prevent electrostatic charge buildup, the tube is equipped with an external conductive coating that must be grounded.

Physical Dimensions and Weight

• Minimum Useful Screen Dimensions:
  • Height: 12-1/16 inches
  • Width: 15-1/4 inches
  • Diagonal: 17-5/8 inches
  • Area: 172 square inches
• Neck Length: 5-1/8 ± 3/16 inches
• Overall Length: 12-5/8 inches (with a documented tolerance of ±3/16 or ±5/16 inches)
• Bulb Designation: J149C
• Bulb Contact: Recessed Small Cavity Cap (J1-21)
• Base: B7-208
• Weight: Approximately 18-1/2 pounds

Deflection Angles

The tube uses magnetic deflection with the following approximate angles:

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

Heater and Electrical Ratings

The 19BNP4 features an indirectly heated cathode with a controlled warm-up time.

Heater Characteristics

• Heater Voltage: 6.3 V
• Heater Current: 0.60 A ± 5%
• Heater Warm-up Time: 11 seconds

Direct Interelectrode Capacitances

• Cathode to All Other Electrodes: Approximately 5 µµf
• Grid No. 1 to All Other Electrodes: Approximately 6 µµf
• External Conductive Coating to Anode: 1000 µµf (minimum) to 1500 µµf (maximum)

Maximum Ratings (Design Maximum Values)

All maximum ratings are specified for Cathode Drive Service, where voltages are positive with respect to Grid No. 1 unless otherwise indicated:

• Maximum Anode Voltage: 20,000 V dc
• Minimum Anode Voltage: 12,000 V dc
• Grid No. 4 Voltage (Focusing Electrode): -550 to +1100 V dc
• Grid No. 2 Voltage: 70 V dc
• Cathode Voltage:
  • Negative Bias Value: 0 V dc
  • Negative Peak Value: 2 V
  • Positive Bias Value: 155 V dc
  • Positive Peak Value: 220 V
• Peak Heater-Cathode Voltage:
  • Heater negative with respect to cathode during warm-up (≤ 15 seconds): 450 V
  • Heater negative with respect to cathode after warm-up: 200 V
  • Heater positive with respect to cathode: 200 V

Typical Operating Conditions (Cathode Drive Service)

Under typical operating conditions, voltages are referenced positive with respect to Grid No. 1:

• Anode Voltage: 16,000 V dc
• Grid No. 4 Voltage for Focus: 0 to +400 V dc
• Grid No. 2 Voltage: 50 V dc
• Cathode Voltage Required for Cutoff: +32 to +50 V dc (for visual extinction of a focused raster). Note: Extinction of a stationary focused spot requires approximately 5 V more positive values.

Circuit Values

• Grid No. 1 Circuit Resistance: 1.5 Megohms maximum

Basing and Pin Connections

The 19BNP4 uses a B7-208 base with an 8HR basing configuration. The anode connection is made via a Recessed Small Cavity Cap (J1-21), which connects to the anode (Grid No. 3 and Grid No. 5). Base Pin No. 4 aligns with the horizontal centerline within 30° and is located on the same side as the anode contact.

There are minor discrepancies in the documented pinout configurations for the 8HR base in technical literature:

Technical Summary

The 19BNP4 is a 19-inch rectangular glass television picture tube designed for cathode-drive service. It features a 114° diagonal magnetic deflection angle, electrostatic focusing, and an aluminized P4 phosphor screen with a bonded gray filter glass safety plate (FP159A) providing 44% light transmittance. Operating with a 6.3 V, 0.60 A heater, the tube requires an anode voltage between 12,000 V and 20,000 V (typically 16,000 V) and utilizes an 8HR basing arrangement with a B7-208 base and a J1-21 recessed small cavity cap for the high-voltage anode connection.