| 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} | 
| 277.1 | DF | .~.~.~ Selectively or alternately connected to receiver {1} | 
| 277.2 |  | .~.~.~.~ By signal quality (e.g., noise) |