Help:

• Use left mouse to click to a frequency.
• Drag right mouse to shift frequency
• Use mouse wheel to increment/decrement frequency by Step amount.
• Enter frequency in kHz and hit Return or press Set Frequency (kHz).
• Hold keyboard Shift and right or left arrow to shift frequency by step size, Control-Shift for 10x step size
• Tick the 'Activate cursor' box to enable cursor: use wheel or click to select cursor location.
• Click on the 'Autoscale' button to set amplitude range to fit current spectrum
• The 'Max hold decay' setting adjusts how slowly the max hold trace decays
• The Channel Memory box saves / restores up to 50 current frequencies and modes with descriptions.
• Space bar toggles audio (when not in full screen mode)
• 'f' to toggle fullscreen mode on and off

If the spectrum display/waterfall is full screen, these keyboard shortcuts are active:

• Press space to toggle pause/run mode (only when focused on the spectrum display, otherwise audio is toggled)
• 'f' to toggle fullscreen mode on and off
• 'c' to step through the colormap options
• up/down arrow shifts the spectrum trace up/down
• left/right arrow increases/decreases amplitude range
• 's'/'w' to increase/decrease size of spectrum display
• '+'/'-' to increase/decrease FFT averaging
• 'm' to toggle max hold mode
• 'z' to center spectrum
• 'i' to zoom in spectrum
• 'o' to zoom out spectrum
• 'a' to autoscale