Which component is used for inputting frequency changes in the RMU?

The small knob is utilized for inputting frequency changes in the Radio Management Unit (RMU). This component allows the pilot to make precise adjustments to the frequency settings, which is crucial for effective communication and navigation in an aircraft. The design of the RMU incorporates this small knob for ease of use, allowing for quick and accurate tuning during flight operations.

The large knob, while it may be involved in other functions, is typically used for general volume adjustments rather than frequency changes. The field select keys are primarily designated for selecting pre-defined channels or functionalities instead of manual frequency inputs. The transfer switch serves a different purpose entirely, mainly related to switching between different radio sources or systems, not for frequency adjustment. Understanding these specific roles within the RMU enhances operational efficiency and pilot capability in managing communication systems.