455 / | HD | TELECOMMUNICATIONS |
130 | DF | RECEIVER OR ANALOG MODULATED SIGNAL FREQUENCY CONVERTER {24} |
150.1 | DF | .~ Signal selection based on frequency (e.g., tuning) {13} |
161.1 | DF | .~.~ Frequency scanning {9} |
169.1 | .~.~.~ With particular variable voltage or current tuning {1} | |
169.2 | DF | .~.~.~.~> With varactor diode |