17CKP4 Television Picture Tube

The 17CKP4 is a 17-inch rectangular glass, direct-view television picture tube. It features low-voltage electrostatic focusing and 110-degree magnetic deflection. The tube is designed with a straight electron gun that does not require an ion trap, an aluminized screen to maximize light output and minimize screen charging, and an external conductive coating that serves as a supplementary filter capacitor when grounded.

Mechanical and Optical Design

The 17CKP4 is constructed with a rectangular glass envelope and a spherical, neutral gray glass faceplate. The faceplate provides an approximate light transmission of 76% to 78% at its center. The minimum useful screen dimensions are:

• Diagonal: 15-3/4 inches
• Width: 14-3/4 inches
• Height: 11-11/16 inches
• Total Useful Area: 155 square inches

The physical dimensions of the bulb (designation J132-1/2 A1 or equivalent) are:

• Greatest Diagonal: 16-9/16 ± 1/8 inches (or ± 0.100 inches)
• Greatest Width: 15-5/8 ± 1/8 inches (or ± 0.100 inches)
• Greatest Height: 12-3/4 ± 1/8 inches (or ± 0.100 inches)
• Overall Length: 12-9/16 ± 1/4 inches (up to ± 5/16 inches)
• Neck Length: 5-7/16 inches (with a tolerance of +3/16 to -1/8 inches)
• Neck Diameter: 1.168 inches maximum at the splice

The net weight of the tube is approximately 10 to 10-1/3 pounds. The tube is designed to be mounted in any position.

Heater and Basing Configuration

The 17CKP4 is equipped with an indirectly heated cathode. The heater has the following ratings:

• Heater Voltage (AC or DC): 6.3 V
• Heater Current: 0.6 A (with a tolerance of ± 10%)
• Heater Warm-up Time: 11 seconds

The 11-second warm-up time is defined by two standard test methods:

1. The time required to reach 80% of the rated heater voltage when four times the rated voltage is applied in series with an external resistance equal to three times the rated voltage divided by the rated current.
2. The time required to reach 5.0 V in a test circuit with an applied voltage of 25 V and a series resistance of 31.5 ohms.

The tube uses the 8HR basing designation. The base is a Small-Button Eightar 7-pin base (JETEC No. B7-183), and the anode terminal is a recessed small-cavity cap (JETEC No. J1-21). The anode terminal is located on the same side of the tube as pin 4. The plane passing through the tube axis and base pin 4 may vary from the plane passing through the axis and the anode terminal by ±30 degrees.

The pin connections are:

• Pin 1: Heater
• Pin 2: Grid No. 1
• Pin 3: Grid No. 2
• Pin 4: Focusing Electrode (Grid No. 4)
• Pin 6: Grid No. 1
• Pin 7: Cathode
• Pin 8: Heater
• Cap: Anode (Anode, Grid No. 3, and Grid No. 5 are connected together internally)

Electrical and Deflection Characteristics

The 17CKP4 utilizes magnetic deflection with approximate deflection angles of:

• Diagonal: 110°
• Horizontal: 105°
• Vertical: 87°

The screen uses an aluminized P4 sulfide phosphor, which exhibits white fluorescence and white phosphorescence with short persistence. The external conductive coating on the glass envelope forms a supplementary filter capacitor when grounded.

The interelectrode capacitances are:

• Grid No. 1 to all other electrodes: 6 µµF
• Cathode to all other electrodes: 5 µµF
• External conductive coating to anode: 800 µµF minimum to 1500 µµF maximum (specifically, a range of 800 to 1400 µµF or 1000 to 1500 µµF depending on the manufacturer specification)

Operating Conditions and Drive Configurations

The 17CKP4 can be operated using either grid-drive or cathode-drive configurations. Operation below an anode voltage of 12,000 V is not recommended because brightness, focus, and definition decrease.

Grid Drive Operation (Video Signal to Grid No. 1)

Under grid-drive conditions, the typical operating parameters are:

• Anode Voltage: 14,000 V to 16,000 V DC
• Grid No. 2 Voltage: 300 V to 400 V DC
• Grid No. 4 (Focusing Electrode) Voltage: 0 to 400 V DC (or up to 500 V DC)
• Grid No. 1 Raster Cutoff Voltage: -28 to -72 V DC (at 14,000 V anode / 300 V G2) or -36 to -94 V DC (at 16,000 V anode / 400 V G2)
• Focusing Electrode Current: -15 to +25 µA DC

Cathode Drive Operation (Video Signal to Cathode)

Under cathode-drive conditions, the typical operating parameters are:

• Anode to Grid No. 1 Voltage: 14,000 V to 16,000 V DC
• Grid No. 2 to Grid No. 1 Voltage: 300 V to 400 V DC
• Grid No. 4 to Grid No. 1 Voltage: 0 to 400 V DC
• Cathode to Grid No. 1 Raster Cutoff Voltage: 28 to 60 V DC (at 14,000 V anode / 300 V G2) or 36 to 78 V DC (at 16,000 V anode / 400 V G2)

Maximum Ratings and Circuit Limits

The maximum ratings are established as design-center values:

• Anode Voltage: 15,000 V to 16,000 V DC maximum
• Focusing Electrode (Grid No. 4) Voltage: -500 V to +1000 V DC maximum
• Grid No. 2 Voltage: 500 V DC maximum
• Grid No. 1 Voltage:
  • Negative-Bias Value: 140 V DC maximum
  • Negative-Peak Value: 200 V maximum
  • Positive-Bias Value: 0 V DC maximum
  • Positive-Peak Value: 2 V maximum
• Peak Heater-Cathode Voltage:
  • Heater Negative with respect to Cathode: 180 V DC maximum (during warm-up for the first 15 seconds, this limit is 410 V maximum)
  • Heater Positive with respect to Cathode: 180 V DC maximum

Limiting Circuit Values

• Grid No. 1 Circuit Resistance: 1.5 MΩ maximum
• Grid No. 2 Circuit Resistance: 10,000 Ω to 0.1 MΩ minimum (protective resistance is advised)
• Focusing Electrode Circuit Resistance: 10,000 Ω to 0.1 MΩ minimum (protective resistance is advised)

Safety and X-Ray Considerations

The 17CKP4 is capable of operating at voltages up to an absolute maximum value of 17.6 kV. If the operating anode voltage exceeds 16 kV, appropriate shielding may be required to protect personnel against X-ray radiation.