19BMP4 Television Picture Tube

The 19BMP4 is a directly viewed, rectangular glass television picture tube. It is designed with a short, improved electron gun that eliminates the need for an external ion trap magnet while providing enhanced edge focus. Electrically, the 19BMP4 is identical to the 19BLP4. The tube features an external conductive coating and a short integral glass button base with straight-through leads and an indexing lug.

Electro-Optical and Mechanical Specifications

The 19BMP4 utilizes electrostatic focusing combined with magnetic deflection. Its physical and optical characteristics are optimized for compact television receiver designs.

Deflection and Screen Characteristics

• Deflection Angles (approximate): Horizontal: 102°, Vertical: 86°, Diagonal: 114°
• Phosphor: Aluminized P4, which produces a white fluorescent color with medium-short persistence.
• Faceplate (Bonded Shield): FP159A2 with a light transmission of approximately 44% at the center.
• Minimum Useful Screen Dimensions: 172 square inches, with a diagonal of 17-3/4 inches, a width of 15-1/16 inches, and a height of 12-1/16 inches.

Physical Dimensions and Base

• Overall Length: 11-9/16 ± 1/4 inches
• Neck Length: 4-7/16 ± 1/16 inches
• Bulb Dimensions: Diagonal: 19.856 ± 0.094 inches; Width: 17.264 ± 0.094 inches; Height: 14.090 ± 0.094 inches
• Bulb Designation: J149-C1
• Base Type: B7-208
• Basing Configuration: 8HR
• Anode Contact: J1-21 cavity contact, which aligns with Pin #4 within a tolerance of ± 30°.

Heater and Interelectrode Capacitances

The 19BMP4 is designed for operation in series or parallel heater strings, featuring a controlled warm-up characteristic.

Heater Ratings

• Heater Voltage: 6.3 V
• Heater Current: 0.600 ± 0.030 A (at 6.3 V)
• Heater Warm-up Time: 11 seconds. This is defined as the time required to reach 80% of the rated heater voltage in a series circuit with a resistance equal to three times the rated heater voltage divided by the rated current, after applying four times the rated voltage.

Interelectrode Capacitances

• Cathode to all other electrodes: 4 µµF (approximate)
• Grid #1 to all other electrodes: 5 µµF (approximate)
• External conductive coating to anode: 1300 pF minimum / 1700 pF maximum

Grid Drive Service

In grid drive service, operating voltages are referenced to the cathode.

Design-Maximum Ratings

• Anode Voltage (Anode, Grid #3, Grid #5): 20,000 V max. DC
• Grid #4 Voltage: -550 to +1100 V DC
• Grid #2 Voltage: 200 to 550 V DC
• Grid #1 Voltage:
  • Negative bias: 154 V max. DC
  • Negative peak: 220 V max.
  • Positive bias: 0 V max. DC
  • Positive peak: 2 V max.
• Peak Heater-Cathode Voltage:
  • Heater negative to cathode (during warm-up ≤ 15 s): 450 V max.
  • Heater negative to cathode (after warm-up): 200 V max.
  • Heater positive to cathode: 200 V max.

Typical Operating Conditions

• Anode Voltage: 16,000 V DC
• Grid #4 Voltage (Focusing Electrode): 0 to +400 V DC
• Grid #2 Voltage: 400 V DC
• Grid #1 Voltage (for raster extinction): -36 to -94 V DC. The cutoff of an undeflected spot increases the required bias magnitude by approximately 5 V.

Maximum Circuit Values

• Grid #1 Circuit Resistance: 1.5 MΩ max.

Cathode Drive Service

In cathode drive service, operating voltages are referenced to Grid #1.

Absolute-Maximum Ratings

• Anode Voltage: 20,000 V max. DC
• Grid #4 Voltage: -400 to +1250 V DC
• Grid #2 Voltage: 350 to 700 V DC
• Cathode Voltage:
  • Positive bias: 154 V max. DC
  • Positive peak: 220 V max.
  • Negative bias: 0 V max. DC
  • Negative peak: 2 V max.
• Peak Heater-Cathode Voltage:
  • Heater negative to cathode (during warm-up ≤ 15 s): 450 V max.
  • Heater negative to cathode (after warm-up): 200 V max.
  • Heater positive to cathode: 200 V max.

Typical Operating Conditions

• Anode Voltage: 16,000 V DC
• Grid #4 Voltage (Focusing Electrode): 0 to +400 V DC
• Grid #2 Voltage: 400 V DC
• Grid #1 Voltage: 0 V DC
• Cathode Voltage (for raster extinction): +36 to +78 V DC. The cutoff of an undeflected spot increases the required bias magnitude by approximately 5 V.

Maximum Circuit Values

• Grid #1 Circuit Resistance: 1.5 MΩ max.

Safety Considerations

When operating the 19BMP4, safety precautions regarding X-ray radiation must be observed. X-ray shielding may be required if the tube is operated at anode voltages exceeding 16,000 V.