| 455 / | HD | TELECOMMUNICATIONS |
| 130 | DF | RECEIVER OR ANALOG MODULATED SIGNAL FREQUENCY CONVERTER {24} |
| 269 | DF | .~ With wave collector (e.g., antenna) {4} |
| 272 | DF | .~.~ Plural separate collectors {5} |
| 278.1 | DF | .~.~.~ Combined with noise or interference elimination {1} |
| 279.1 | ![]() | .~.~.~.~ Plural antenna currents entering single transformer |