17CLP4 — 17-Inch Rectangular Cathode Ray Tube

The 17CLP4 is a short-neck, 17-inch rectangular direct-view picture tube designed for television applications. It features electrostatic focusing, 90-degree magnetic deflection, and a metal-backed screen.

Mechanical and Physical Characteristics

The 17CLP4 is constructed with a rectangular gray filter glass faceplate that provides approximately 74% light transmission. The screen utilizes an aluminized P4 phosphor, which exhibits white fluorescence and medium persistence.

The physical dimensions of the tube are:

• Overall Length: 15-5/8 ± 3/8 inches
• Greatest Diagonal Dimension: 16-5/8 ± 1/8 inches
• Greatest Width: 15-3/8 ± 1/8 inches
• Greatest Height: 12-9/32 ± 1/8 inches
• Minimum Useful Screen Dimensions: 11-1/8 x 14-5/16 inches
• Minimum Useful Screen Area: 149 square inches

Electrical connection to the high-voltage anode is made via a Recessed Small Cavity Cap (J1-21) located on the bulb. The base is a Small Shell Duodecal 6-pin (B6-63) with a 12L basing designation. The J1-21 bulb contact aligns with Pin No. 6 within a tolerance of ±30 degrees.

Heater and Pinout Configuration

The 17CLP4 is equipped with an indirectly heated cathode. The nominal heater ratings and tolerances are:

• Heater Voltage: 6.3 V
• Heater Current: 0.6 ± 10% A

The 12L basing arrangement provides the following pin connections, viewed from the bottom of the base:

Interelectrode Capacitances

The approximate interelectrode capacitances of the tube are:

• Cathode to All Other Electrodes: 5 µµF
• Grid No. 1 to All Other Electrodes: 6 µµF
• External Conductive Coating to Anode: 1800 µµF minimum, 2300 µµF maximum

The high-capacity external conductive coating, when properly grounded, functions as a filter capacitor for the high-voltage supply and assists in radiation suppression.

Electrical Ratings and Operating Conditions

The operating limits and typical operating parameters of the 17CLP4 are categorized into absolute maximum ratings and typical operating conditions.

Absolute Maximum Ratings

• Final Anode Voltage: 17,600 V DC
• Grid No. 4 Voltage (Focusing Electrode): -550 to +1,100 V DC
• Grid No. 2 Voltage: 550 V DC
• Grid No. 1 Voltage:
  • Negative Bias Value: 155 V DC
  • Negative Peak Value: 220 V DC
  • Positive Peak Value: 2 V
  • Positive Bias Value: 0 V
• Peak Heater-Cathode Voltage:
  • Heater negative with respect to cathode (during warm-up, ≤ 15 seconds): 450 V DC
  • Heater negative with respect to cathode (after warm-up): 200 V DC
  • Heater positive with respect to cathode: 200 V DC

Typical Operating Conditions

• Anode Voltage: 14,000 V DC
• Grid No. 4 Voltage for Focus: -48 to +264 V DC (the focus electrode may be modulated to improve overall focus)
• Grid No. 2 Voltage: 300 V DC
• Grid No. 1 Voltage for Cutoff: -35 to -72 V DC (required for visual extinction of the focused raster)
• PM Ion Trap Magnet Field Strength: 35 Gausses (for a typical permanent magnet ion trap magnet with a ±3 gausses tolerance)

Circuit Design and Safety Considerations

The maximum grid No. 1 circuit resistance must not exceed 1.5 Megohms.

Because the tube operates at high voltages, safety precautions regarding radiation must be observed. Specifically, X-ray radiation shielding may be necessary if the tube is operated at voltages exceeding 16,000 Volts.

Technical Summary

The 17CLP4 is a 17-inch rectangular, 90-degree magnetic deflection picture tube featuring electrostatic focus and a short-neck design. It operates with a 6.3 V, 0.6 A heater and utilizes a Small Shell Duodecal 6-pin base. The tube is characterized by its aluminized P4 phosphor screen, gray filter glass faceplate, and an external conductive coating that provides filtering and radiation suppression. With a maximum anode rating of 17,600 V DC and typical operation at 14,000 V DC, it requires an external single-field ion trap magnet and may require X-ray shielding when operated above 16,000 V.