Abstract: A graphical tuning system for computer-controlled radio equipment, where a two-dimensional tuning field is displayed with one axis representing frequency and the other axis representing tuning resolution. The user tunes the equipment by moving a pointer in this two-dimensional field. A spectrum display may be superimposed as a third dimension on a two-dimensional tuning field with one axis representing the frequency, the second axis representing tuning resolution and the third axis representing the signal level. The preferred tuning relationship is described by the generalized equation: f2=f1+(x2−x1)*FR(y2−y1), where f1 is the old frequency, and f2 is the new frequency, where x1, y1 are the new co-ordinates of the mouse, x2, y2 are the old co-ordinates of the mouse, and FR is a function describing a relationship between the position of the mouse and the frequency resolution.

Abstract: A radio receiver comprises an RF tuner (10) on a computer card (11) having a frequency selector (19) for determining the current selected frequency. A programmed computer functions as a control system 100 controlling the tuner and a display screen 200 presents data and user selectable inputs to the user. An input peripheral device (101) enables the user to input data or information and commands to the control system. The control system causes a display (220) display on the display screen (200) in real time both digital and analogue indications of the current frequency being passed by the tuner (10); and provides a tuner frequency select control responsive to input of a frequency change command by the user to change the current selected frequency.