17RP4 — Direct-View Cathode Ray Picture Tube

An all-glass, rectangular, direct-view cathode ray picture tube featuring low-voltage electrostatic focus and magnetic deflection, designed for television receiver applications.

Overview

The 17RP4 is a rectangular, direct-view cathode ray picture tube designed primarily for television receiver applications. It features low-voltage electrostatic focusing and magnetic deflection. The tube incorporates a unipotential cathode, a gray filter faceplate, an external conductive coating, and is designed for use with an external single-field ion-trap magnet.

The 17RP4 is identical in characteristics to the 17HP4. It is also identical to the 17RP4C, with the sole distinction that the 17RP4 features a non-aluminized screen, whereas the 17RP4C features an aluminized screen.

Mechanical Specifications and Physical Dimensions

The 17RP4 utilizes a rectangular glass bulb (ASA designation J133-A1 or -B1) with a spherical gray faceplate. The physical dimensions and mechanical characteristics are as follows:

• Overall Length: 19 1/4 ± 3/8 inches or 19 3/8 ± 3/8 inches
• Neck Length: 7 1/2 inches
• Greatest Bulb Dimensions:
  • Diagonal: 16 5/8 ± 1/8 inches
  • Width: 15 3/8 ± 1/8 inches (also specified as 15 25/64 ± 1/8 inches)
  • Height: 12 1/4 ± 1/8 inches
• Minimum Useful Screen Dimensions:
  • Diagonal: 15 1/2 inches
  • Width: 14 1/4 inches
  • Height: 10 3/4 inches
• Raster Size: 14 1/4 inches by 10 3/4 inches
• Approximate Net Weight: 16 lbs
• Mounting Position: Any

The faceplate is a gray filter glass providing light transmission at the center of approximately 66% to 72%.

Electron Gun, Heater, and Basing

The tube is equipped with an electron gun designed for use with an external single-field ion-trap magnet. The heater is rated for a nominal voltage of 6.3 V and a current of 0.6 A (with a tolerance of ±10%).

The 17RP4 uses a Small Shell Duodecal 6-Pin base (JETEC No. B6-63) with a 12L basing configuration. High voltage is applied via a recessed small cavity cap (JETEC No. J1-21) located on the bulb. The anode contact aligns with pin position No. 6 within a tolerance of ±30 degrees.

Pin Connections (Bottom View)

Electrostatic and Optical Characteristics

The 17RP4 utilizes a No. 4 (P4) sulfide-type phosphor screen. It exhibits white fluorescence and white phosphorescence, with persistence described as medium or short.

Deflection Angles (Approximate)

• Horizontal: 66 degrees
• Diagonal: 70 degrees

Interelectrode Capacitances (Approximate)

• Cathode to all other electrodes: 5 µµF
• Grid No. 1 to all other electrodes: 6 µµF
• External conductive coating to anode: 750 µµF (minimum) to 1,500 µµF (maximum)

The external conductive coating, when properly grounded, serves as a filter capacitor for the high-voltage power supply.

Maximum Ratings (Design-Center Values)

The following maximum ratings are established under the Design-Center system:

• Anode (Grid No. 3, Grid No. 5) Voltage: 16,000 V DC maximum
• Focusing Electrode (Grid No. 4 / Anode No. 1) Voltage: -500 to +1,000 V DC maximum
• Focusing Electrode Current: -15 to +25 µA DC maximum (measured at design-center maximum anode voltage plus 10%)
• Grid No. 2 Voltage: 500 V DC maximum
• Grid No. 1 Voltage:
  • DC Negative-Bias Value: 125 V DC maximum
  • DC Positive-Bias Value: 0 V DC maximum
  • Positive-Peak Value: 2 V maximum
• Peak Heater-Cathode Voltage:
  • Heater negative with respect to cathode (during warm-up ≤ 15 seconds): 410 V maximum
  • Heater negative with respect to cathode (after warm-up): 180 V maximum
  • Heater positive with respect to cathode: 180 V maximum
• Grid No. 1 Circuit Resistance: 1.5 MΩ maximum

Typical Operating Conditions

The 17RP4 can be operated under typical conditions with anode voltages of 12,000 V or 14,000 V DC. While 12,000 V is a standard operating point, performance characteristics such as brightness and focus quality may decrease below 14,000 V, and the anode voltage should not be operated below 12,000 V.

The focusing electrode voltage may be modulated within its maximum range to improve overall focus across the raster without causing damage to the tube.

Technical Summary

The 17RP4 is a rectangular, direct-view cathode ray picture tube featuring low-voltage electrostatic focus and magnetic deflection. It is designed with a unipotential cathode, a gray filter faceplate, and an external conductive coating that functions as a filter capacitor. The tube operates with a 6.3 V, 0.6 A heater and is housed in a glass bulb with a Small Shell Duodecal 6-Pin base (12L basing). It is electrically identical to the 17HP4, and is identical to the 17RP4C except for its non-aluminized screen. With a design-center maximum anode voltage rating of 16,000 V, the 17RP4 typically operates at 12,000 V to 14,000 V, utilizing an external single-field ion-trap magnet to ensure proper beam alignment and raster illumination.