19EKP4 Television Picture Tube
A 19-inch direct-view rectangular glass television picture tube featuring magnetic deflection, electrostatic focusing, and a cathode-drive design.
Overview
The 19EKP4 is a 19-inch direct-view rectangular glass television picture tube. It features a gray filter glass, an aluminized screen, and a cathode-drive design. The tube incorporates a filled rim implosion protection system, where the rim itself provides mounting holes, and does not require an ion trap. It is designed for magnetic deflection and electrostatic focusing, utilizing a low Grid #2 (G2) operating voltage of 45 V.
Mechanical Specifications and Optical Characteristics
Physical Dimensions
- Overall Length: 11 5/8 inches ± 1/4 inch
- Neck Length: 4 3/8 inches ± 1/8 inch
- Greatest Dimensions (including Metal Rim):
- Diagonal: 20 13/16 inches ± 3/32 inch
- Width: 17 5/32 inches ± 1/16 inch
- Height: 14 3/32 inches ± 1/16 inch
- Minimum Useful Screen Dimensions (Projected):
- Diagonal: 17 9/16 inches
- Horizontal Axis: 15 1/8 inches
- Vertical Axis: 12 inches
- Total Area: 172 square inches
Envelope and Basing
The tube uses a J149F1 bulb with a J1-21 bulb contact and a B6-214 base. The basing configuration is designated as 7FA. The J1-21 bulb contact aligns with pin position #7 within a tolerance of ± 30°.
Optical Data
- Phosphor: P4 Aluminized
- Light Transmittance: Approximately 49% at the center of the screen.
Electrical and Deflection Characteristics
Deflection and Focusing
The 19EKP4 employs magnetic deflection and electrostatic focusing. The approximate deflection angles are:
- Diagonal: 114°
- Horizontal: 103°
- Vertical: 86°
Heater Ratings
The heater is designed for a nominal voltage of 6.3 V with a controlled warm-up time.
- Heater Voltage: 6.3 V (Design limits: 5.8 V minimum to 7.0 V maximum)
- Heater Current: 450 ± 5% mA
- Heater Warm-up Time: 11 seconds
Direct Interelectrode Capacitances
- Cathode to all other electrodes: Approximately 5 µµF
- Grid #1 to all other electrodes: Approximately 6 µµF
- External conductive coating to anode (including implosion protection hardware): 1,000 µµF minimum to 1,500 µµF maximum
Operating Conditions and Design Maximums
All voltages are specified positive with respect to Grid #1, unless otherwise noted.
Design Maximum Ratings
- Anode Voltage: 12,000 V minimum to 19,800 V maximum
- Grid #4 (Focusing Electrode) Voltage: -500 V to +1100 V
- Grid #2 Voltage: 30 V minimum to 55 V maximum
- Cathode Voltage: 100 V maximum
- Heater-Cathode Voltage:
- Heater negative with respect to cathode: 410 V maximum during warm-up (≤ 15 seconds), 180 V maximum after warm-up
- Heater positive with respect to cathode: 180 V maximum
Typical Operating Conditions (Cathode Drive Service)
Under typical cathode drive operation, the operating parameters are:
- Anode Voltage: 16,000 V DC
- Grid #4 (Focusing Electrode) Voltage: 250 V DC (satisfactory focus is obtained between 0 V and 500 V DC, measured with combined Grid #1 bias and video-signal adjusted for a 150 µA anode current on a 15 1/8 inch by 12 inch pattern)
- Grid #2 Voltage: 45 V DC
- Cathode Voltage (for visual extinction of focused raster): 35 V to 50 V DC
Special Characteristics and Circuit Limits
- Anode Penetration Current: Under test conditions with 19,800 V applied to the anode, and zero voltage applied to the Cathode, Grid #1, and Grid #2 (with other elements at nominal voltages), the anode penetration current is a maximum of 150 µA.
- Maximum Grid #1 Circuit Resistance: 1.5 Megohms
Technical Summary
The 19EKP4 is a 19-inch rectangular glass television picture tube designed for cathode-drive service. It features a short-neck design with an overall length of 11 5/8 inches, magnetic deflection with a wide 114° diagonal angle, and low-voltage electrostatic focusing. The tube utilizes a P4 aluminized phosphor screen with a gray filter glass providing 49% light transmittance, and is protected by a filled rim implosion system. Operating at a typical anode voltage of 16,000 V and a low Grid #2 voltage of 45 V, the 19EKP4 provides a compact, high-performance display solution for television receivers without requiring an external ion trap.
