| 455 / | HD | TELECOMMUNICATIONS |
| 130 | DF | RECEIVER OR ANALOG MODULATED SIGNAL FREQUENCY CONVERTER {24} |
| 230 | DF | .~ Local control of receiver operation {7} |
| 232.1 | DF | .~.~ Gain control {2} |
| 234.1 | DF | .~.~.~ Automatic {15} |
| 251.1 | ![]() | .~.~.~.~ Plural stages with different levels or bias to each stage (e.g., partial automatic gain control) |