| 313 / | HD | ELECTRIC LAMP AND DISCHARGE DEVICES |
| 364 | DF | CATHODE RAY TUBE {11} |
| 441 | DF | .~ Ray generating or control {6} |
| 446 | | .~.~ Including cathode assembly {2} |
| 447 | DF | .~.~.~> With control grid adjacent cathode {1} |
| 452 | DF | .~.~.~> With focus electrode adjacent cathode {2} |