Specialized - Cathode Ray ·CathodeRay
Nineteen-inch direct-view monochrome television picture tube with electrostatic focusing, magnetic deflection, and an aluminized P4 screen. Manufacturer documentation places it in the high-voltage picture-tube family used for bright, high-contrast receiver display.
The 19CDP4 is a 19-inch direct-view rectangular glass cathode-ray tube (CRT) designed for television receiver applications. It features a cathode-drive design, electrostatic focusing, and a wide-angle magnetic deflection system. The tube incorporates an aluminized screen with a P4 phosphor, a spherical faceplate made of gray filter glass with approximately 78% light transmittance at the center, and an external conductive coating. Notably, the design operates with a low Grid No. 2 voltage and does not require an ion trap magnet.
The 19CDP4 is constructed with a rectangular glass envelope using a J 149 A1 bulb (or equivalent) and a B6-214 base. The physical dimensions of the tube are as follows:
The screen is designed to maximize the useful viewing area within its compact physical footprint. The minimum useful screen dimensions (projected) are:
The faceplate is spherical and composed of gray filter glass, which provides an approximate light transmittance of 78% at the center to improve contrast under ambient light. The screen uses P4 phosphor and is aluminized to enhance brightness and efficiency.
The tube features an external conductive coating that acts as a capacitor in conjunction with the internal anode coating. The capacitance between the external conductive coating and the anode ranges from a minimum of 1400 µµf to a maximum of 1900 µµf.
The 19CDP4 utilizes magnetic deflection with a diagonal deflection angle of 114°. The horizontal and vertical deflection angles are:
Focusing is accomplished electrostatically via Grid No. 4 (the focusing electrode). This design allows for a wide range of focus adjustment, with satisfactory focus obtainable between 0 V and 500 V under typical operating conditions.
The 19CDP4 is equipped with a heater designed for reliable operation and controlled warm-up.
The tube uses a B6-214 base with a 7FA pinout configuration. The electrical connections are as follows:
The anode contact (recessed small cavity cap J1-21) is aligned with pin position #7 within a tolerance of ± 30°.
The direct interelectrode capacitances of the tube (approximate values) are:
The ratings of the 19CDP4 are established under the Design-Maximum System. Unless otherwise specified, all voltages are positive and measured with respect to Grid No. 1.
| Parameter | Minimum Value | Maximum Value |
|---|---|---|
| Anode Voltage | 12,000 V | 19,800 V |
| Grid No. 4 (Focusing Electrode) Voltage | -500 V | +1100 V |
| Grid No. 2 Voltage | 40 V | 70 V |
| Cathode Voltage | — | 100 V |
| Heater Voltage | 5.8 V | 7.0 V |
| Grid No. 1 Circuit Resistance | — | 1.5 MΩ |
The maximum allowable voltage difference between the heater and the cathode depends on the polarity and the operating state of the equipment:
In typical cathode-drive service, the control voltages are referenced to Grid No. 1. Under these conditions, the operating parameters are:
The cathode-drive configuration allows the video signal to be applied directly to the cathode, which can offer advantages in drive circuitry design. The low Grid No. 2 voltage rating of 50 V simplifies the power supply requirements for the screen grid.
The 19CDP4 is a 114° magnetic deflection, electrostatically focused rectangular television picture tube featuring a 19-inch diagonal screen. It is designed for cathode-drive operation with a low Grid No. 2 voltage of 50 V and does not require an ion trap. The tube incorporates an aluminized P4 phosphor screen, a gray filter glass faceplate with 78% center light transmittance, and an external conductive coating. Operating with a nominal 6.3 V, 600 mA heater, the 19CDP4 provides a minimum useful screen area of 172 square inches. It is rated for anode voltages up to 19,800 V and features a 7FA basing configuration with a recessed small cavity cap for the anode connection.
Duodecal 12-contact
General specifications
Properties common to every published source and operating point.
Electrical assignments shared by every tube using this base designation.
No verified pinout is recorded for this base designation.
1 physical section, each with unique specifications.
Section 1
CRT accelerator/final-anode maximum mapped to MaxPlateVoltage.
Source-dependent data
Each block preserves the test conditions and published values from one reference. Values from different sources are intentionally kept separate.
Data set 01
Published operating points and test conditions from this source.
Heater voltage
6.3 V
Heater current
600 mA
Typical anode/accelerator voltage
19800 V
Typical grid 2 voltage
70 V
Maximum heater-cathode voltage
180 V
Heater positive to cathode
Maximum grid 1 circuit resistance
1.5 Mohm
Focusing method
Electrostatic
Deflection method
Magnetic
Deflection angle
103 deg