Getting started

Getting started

From download to your first decoded signals. About five minutes for FM radio, a little more for aircraft.

1. Install

Download the file for your system from the latest release and install it as described on Install: a .dmg on macOS, the setup or zip on Windows, a .deb or portable archive on Linux. On Windows install the USB driver for your radio once (Zadig / WinUSB, or the SDRplay API for an RSP). On macOS the app is not signed yet: right-click it and choose Open the first time.

2. First launch

1. Start OnAir. A Setup wizard asks which radio you have, where you are (it picks the right TV standard and FM band for your country), optionally your position, and what you want to receive. You can run it again any time from Help > Setup wizard.
2. The Guided tour follows: a short walk through the window on a built-in demo signal (Guided tour). Skip it or finish it; Help > Guided tour brings it back.
3. OnAir may ask whether to share decoded positions with the public map. The answer is yours and the default is not to send anything; see Map sharing.

No radio yet? Choose the synthetic source: most modes include a built-in test signal, so you can try every screen.

3. Choose your radio

Plug the radio in and open the source list at the top. Connected radios appear there; press Rescan for devices if yours is missing. Radios on another computer are added with Add network radio... (Network radios).

Radio	What it is good for
RTL-SDR	the cheap start: FM, DAB, airband, many narrow modes, up to about 2.4 Msps and about 24 MHz to 1.7 GHz (RTL-SDR)
HackRF, PlutoSDR, LimeSDR, BladeRF, USRP	wideband: TV channels, 1090 MHz and microwave (wideband radios, HackRF)
Airspy, SDRplay, RX888, Fobos	HF and VHF with better dynamic range (Supported radios)
Sound card	a receiver feeding audio into the computer (Sound card)

A TV channel needs roughly one million samples per second for every MHz of channel width, so it needs a fast radio. The page of each mode says which radios work.

4. Your first signal in five minutes: FM radio

1. In the mode list open the group Broadcast radio and choose FM (shortcut label Stereo and RDS). The search box finds a mode by name.
2. Type a frequency in the tuner, in MHz, between 87.5 and 108 (76 to 95 in Japan). Use the Scan tab to list stations if you do not know one.
3. Set the gain to the middle of its range, or press Auto-tune.
4. Press Start. You see the spectrum and waterfall, a station name and radio text (RDS) appear, and you hear sound through the speaker control or Listen.
5. If the audio hisses, move the antenna, lengthen it, or lower the gain a little if the ADC line says overload. See the FM tutorial for the details.

5. Your next signal: aircraft with ADS-B

ADS-B needs a radio that tunes 1090 MHz and samples at 2 Msps or more (the mode asks for 4 Msps): a HackRF, Airspy, PlutoSDR and similar. A plain RTL-SDR tunes that frequency but check your dongle's rate and the ADS-B mode page first.

1. Choose Aircraft, 1090 MHz in the Aviation group. The start frequency is 1090 MHz.
2. Use an antenna for 1090 MHz, ideally outdoors with a clear view of the sky, and a short cable.
3. Press Start. Aircraft appear on the Map with callsign, altitude and speed; Table, Radar and Range show the same data differently.
4. Switch Predict positions on for smooth movement (Position prediction).
5. The full walk-through is Tutorial: ADS-B.

6. Make it comfortable

• Store what works in the Memory panel (Ctrl+M) and look up well-known frequencies in the Frequency database (Ctrl+Shift+F).
• Pick your country's band plan in the Scan tab.
• On a tablet, switch on the Touch interface.
• Record the sound with Record audio and the raw signal with Record IQ.

If something goes wrong

• No radio in the list, no signal, crackling sound, high CPU: Troubleshooting.
• Questions: FAQ.
• Everything about the screens: Main window. The older walk-through is Your first reception.

Where to go from here

Every mode has a page (Modes) and, for most, a step-by-step tutorial. Bugs and ideas go to GitHub Issues; questions and chat to the Discord.