The 5 Main Menu Keys (also called “hard keys’” in some Anritsu manuals) are located below the measurement display (sweep window). These 5 keys are used to list function‑specific menus in the active menu (submenu key labels or Active Function Block). The submenu keys are also called “soft keys” in some Anritsu manuals. The 5 Main Menu keys vary in function depending upon the selected mode of operation. Table: Mode‑Dependent Main Menu Keys (Located Below Measurement Display) lists the Main Menu key labels for the DTV modes that are described in this measurement guide.