455 / | HD | TELECOMMUNICATIONS |
130 | DF | RECEIVER OR ANALOG MODULATED SIGNAL FREQUENCY CONVERTER {24} |
132 | DF | .~ Plural receivers {4} |
133 | DF | .~.~ With output selecting {3} |
136 | ![]() | .~.~.~ With control (e.g., automatic gain control, automatic frequency control, etc.) |