Specialized - Cathode Ray ·CathodeRay
Twelve-inch P4 television picture tube with magnetic focusing and magnetic deflection. The high-voltage direct-view CRT uses a white picture screen and conventional magnetic beam control for monochrome television presentation.
A twelve-inch magnetic-focus and magnetic-deflection direct-view picture tube designed for television receiver applications.
The 12VP4 is a direct-view cathode-ray tube featuring a twelve-inch bulb diameter. It is designed with an electron gun of triode construction that requires an external ion-trap magnet for proper operation. The tube utilizes magnetic focusing and magnetic deflection, with an approximate deflecting angle of 55 degrees. To assist in circuit operation, the bulb is manufactured with an external conductive coating.
The screen uses a #4 phosphor, which provides a white fluorescence and a medium persistence. This combination is optimized for displaying black-and-white television pictures.
The physical dimensions and mechanical characteristics of the 12VP4 are precisely defined for television chassis integration:
The electrical connections are made through the 5-pin duodecal base and the recessed cavity cap on the bulb. The pin assignments, viewed from the bottom of the base, are as follows:
| Pin / Contact | Connection |
|---|---|
| Pin 1 | Heater |
| Pin 2 | Grid |
| Pin 10 | No Connection |
| Pin 11 | Cathode |
| Pin 12 | Heater |
| Bulb Contact | Anode |
Pin position number 3 is vacant. The bulb contact (anode) is aligned with vacant pin position number 3 within a tolerance of ±10 degrees. An uncoated surface area with a diameter of 4 1/4 inches is maintained around the bulb contact on the cone. The reference line of the tube is established by the position where a ring gauge with an inside diameter of 1.500 inches (+0.003 inches, -0.000 inches) and a length of 2 inches rests on the bulb cone.
The 12VP4 operates with an indirectly heated cathode. The electrical characteristics of the heater and the typical operating parameters of the tube are:
Under typical operating conditions, the tube is configured with the following electrical parameters:
The maximum ratings for the 12VP4 are specified under the Design Center system. Operating the tube beyond these limits may degrade performance or cause permanent damage to the structure.
To protect the heater-cathode insulation, the peak negative heater voltage is permitted to reach 410 volts only during the initial warm-up phase, which must not exceed 15 seconds. Under normal operating conditions after warm-up, the potential difference between the heater and cathode must be kept within 125 volts in either polarity.
The 12VP4 is a twelve-inch, magnetic-focus, magnetic-deflection cathode-ray tube designed for direct-view television applications. It features a triode electron gun designed for use with an external ion-trap magnet, an external conductive coating, and a white-emitting #4 phosphor of medium persistence. Operating with a nominal 6.3 V, 0.6 A heater, the tube is typically operated at an anode voltage of 11,000 V, with a maximum design-center rating of 12,000 V. It is constructed with a J1-21 recessed small cavity cap for the anode connection and a B5-57 small shell duodecal 5-pin base.
Small-shell Duodecal 5-contact CRT base
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
Published maximum ratings and characteristics promoted semantically from the approved source.
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.
Maximum Plate Voltage
12000 V
Typical Anode Voltage
11000 V
Phosphor
P4
Focusing Method
Magnetic
Deflecting Method
Magnetic