Main window

What is where, in the order you will use it.

Items marked (0.2.6) are new since the 0.2.5 release.

OnAir has several layouts (View menu: Sidebar, Scope, Tiles, Faceplate, Scope: Cinema, Scope: Meters, Scope: Dock and Panel), plus a classic interface. They all use the same parts, so this page names the parts rather than the pixels. The layout adapts to small windows and to 125 % and 150 % display scaling.

Menus

Menu	What it holds
File	Exit program.
Mode	Every mode, in 15 groups (the last one is Plugins), with the keys 1 to 9 for the first nine.
View	The layouts, Text size, Reset layout, Reset spectrum (0.2.6; brings back a lost spectrum pane), Full screen, Language, Reduce CPU when hidden, Show in Discord, Passes (satellite pass planner), Images, Data feeds..., Transmit..., Map, Scanner (highly experimental), Antenna rotator..., and the Classic interface.
Server	The opt-in map upload, see Privacy.
Help	Setup wizard and Guided tour.

The top bar

• Start / Stop and the frequency field. The mouse wheel or a trackpad steps the frequency in the classic frequency field; the arrows repeat when held.
• The radio (source) choice and the sample rate.
• Clear all (0.2.6) wipes every decoded list after a confirmation. Results stay until you press Clear, across mode switches and restarts.
• The version button at the top right shows the update state and holds the update settings. Support opens Ko-fi.

Spectrum and waterfall

• The spectrum shows the power of every frequency the radio sees; the waterfall below shows it over time, newest at the top.
• Hover a slider and scroll to change it by one step (Shift = fine, Ctrl = coarse); the window does not scroll meanwhile.
• The dB range fields work at any time; Ctrl+Up / Down moves the range, Ctrl+Shift+Up / Down widens or narrows it and Ctrl+Home resets it.
• Colour maps, pause and scroll-back, averaging, max hold, peak markers and dBm are in the display options (0.2.6); a Cividis colour map helps with red-green colour blindness.
• Click a signal on the spectrum and the signal identifier gives its width, rate, modulation and a suggested mode.
• A decoder counter sits at the top right of the spectrum (0.2.6).

Panels

In the Sidebar layout the panels are folded sections; other layouts show them as tiles or modules:

• Source: choose the radio, press Rescan for devices, Record IQ (see Settings and files), add a network radio or a Hamlib rig.
• Gain: Auto-tune, Optimise gain and the radio's gain stages (for a HackRF: LNA, VGA and the Amp switch). Radio settings offers what the radio has: frequency correction (ppm), notch filters, gain modes, direct sampling for HF, up-converters and LNBs.
• Tuner: the frequency, the sample rate and the mode's own options.
• Mode: the mode list with a search box.
• Display: spectrum range, colour map and waterfall options.
• Decoder: shown for modes that have decoder options.
• Tools (folded, 0.2.6): passes, images, feeds, map, scanner, light theme, accent colour and text size, so they are not only in the View menu.
• Log: what the receiver is doing, with warnings in plain words.

The tabs

The tab bar changes with the mode. A TV mode has:

Tab	Shows
Overview	The key numbers and plots at a glance.
TV	The player (picture, sound, subtitles), the programme Guide, Teletext; record a service to a file, pause and a live buffer (0.2.6).
Receiver	Sync, Signalling, FEC, Frame map and Channel views: the inner workings of the receiver.
Stream	Outputs (record, UDP, network tuner) and the transport stream.
Scan	The channel scanner and the shared channel list.
Antenna	The direction finder that helps you aim the antenna.
History	A log of the signal over time.

Radio modes have a Radio tab (FM) or Radio, Ensemble, Map, Analyzer, Journaline and FIC tabs (DAB). Every other mode has its own tab named after the mode, with sub-views such as Map, Table and Messages; each mode page lists them.

Status and results

• The status bar shows lock state, SNR, quality, whether samples are being dropped, the process CPU load and, for a network radio, the samples lost.
• Save results... writes CSV or JSON, an ADIF logbook for the amateur modes, and KML or GPX for anything with positions.
• Two modes at once from the same capture: add a second mode and its tab appears as Second: <mode>. Several receivers at once: see Use two receivers.