| 455 / | HD | TELECOMMUNICATIONS | 
| 130 | DF | RECEIVER OR ANALOG MODULATED SIGNAL FREQUENCY CONVERTER {24} | 
| 296 | DF | .~ Noise or interference elimination {10} | 
| 308 |  | .~.~ With amplitude limiter {1} | 
| 309 | DF | .~.~.~> In demodulator or low frequency (audio amplifier circuit) |