19EZP4 — Direct-View Cathode Ray Tube

The 19EZP4 is a 19-inch rectangular glass-envelope cathode ray tube designed for direct-view television applications. It features a space-saving short-neck design, 114-degree magnetic deflection, and electrostatic focusing. The tube is characterized by its cathode-drive design, low Grid #2 operating voltage, and an integrated filled-rim implosion protection system.

Mechanical Construction and Optical Features

The 19EZP4 is constructed using a J149F1 rectangular glass bulb with a gray filter glass faceplate. The screen utilizes an aluminized P4 phosphor, which provides a light transmittance of approximately 49% at the center.

To facilitate mounting and enhance safety, the tube incorporates a filled-rim implosion protection system. The metal rim provides four mounting holes, each measuring 1/4 inch in diameter.

Physical Dimensions and Weight

• Overall Length: 11 5/8" ± 1/4"
• Neck Length: 4 3/8" ± 1/8"
• Greatest Dimensions (including Metal Rim):
  • Diagonal: 20 7/16" + 3/32"
  • Width: 16 7/8" ± 1/16"
  • Height: 13 13/16" ± 1/16"
• Minimum Useful Screen Dimensions (Projected):
  • Diagonal: 17 9/16"
  • Horizontal Axis: 15 1/8"
  • Vertical Axis: 12"
  • Total Area: 172 sq. inches
• Approximate Weight: 15 lb. 8 oz.

The tube uses a B6-214 base with a 7FA basing configuration. The high-voltage anode connection is made via a J1-21 bulb contact, which aligns with the pin #7 position within a tolerance of ± 30°.

Electrical Connections and Capacitances

The 19EZP4 utilizes the 7FA basing arrangement. The pinout configuration, viewed from the bottom of the base, is detailed below:

Direct Interelectrode Capacitances

The electrostatic coupling between the tube elements is characterized by the following approximate values:

• Cathode to all other electrodes: 5 µµF
• Grid #1 to all other electrodes: 6 µµF
• External conductive coating to Anode (including implosion hardware): 1,000 µµF minimum to 1,500 µµF maximum

Heater and Electrical Ratings

The 19EZP4 is designed with a controlled heater warm-up time for series-string or parallel operation. All voltage ratings, unless otherwise specified, are positive and measured with respect to Grid #1.

Heater Characteristics

• Nominal Voltage: 6.3 V (Design Maximum limits: 5.8 V minimum to 7.0 V maximum)
• Nominal Current: 450 ± 5% mA
• Warm-up Time: 11 seconds

Design Maximum Ratings

• Anode Voltage: 19,800 Volts maximum; 12,000 Volts minimum
• Grid #4 (Focusing Electrode) Voltage: -500 to +1100 Volts maximum
• Grid #2 Voltage: 55 Volts maximum; 30 Volts minimum
• Cathode Voltage: 100 Volts maximum
• Maximum Heater-Cathode Voltage:
  • Heater negative with respect to cathode during warm-up (not to exceed 15 seconds): 410 Volts
  • Heater negative with respect to cathode after warm-up: 180 Volts
  • Heater positive with respect to cathode: 180 Volts

Typical Operating Conditions

In typical cathode-drive service, the tube operates under the following electrical conditions:

• Anode Voltage: 16,000 Volts DC
• Grid #2 Voltage: 45 Volts DC
• Grid #4 (Focusing Electrode) Voltage: 250 Volts DC (individual tubes focus within a range of 0 to 500 Volts DC under test pattern conditions)
• Cathode Voltage (for visual extinction of focused raster): 35 to 50 Volts DC

Deflection Characteristics

The tube utilizes magnetic deflection with the following approximate deflection angles:

• Diagonal: 114°
• Horizontal: 103°
• Vertical: 86°

Circuit Limits and Special Characteristics

To ensure stable operation and prevent damage to the electron gun, the external circuitry must adhere to the following limits:

• Maximum Grid #1 Circuit Resistance: 1.5 Megohms

Anode Penetration Current

Under specific test conditions—with 19,800 Volts applied to the Anode, zero voltage applied to the Cathode, Grid #1, and Grid #2, and all other elements held at nominal voltages—the maximum anode penetration current is limited to 150 µA.