SDR Reception — Hardware & Software
RTL-SDR, AirSpy, HackRF compared. Setting up SDR# and SDR++. FM radio, aviation ADS-B, AIS ships, NOAA weather satellites — a practical start.
What is SDR?
SDR (software defined radio) moves filters, mixers and demodulators out of the hardware and into software. The hardware only digitises the raw signal — the computer does everything else. A single device can receive FM radio, aviation, TETRA, AIS, weather data and much more.
Hardware comparison
| Device | Frequency | Bandwidth | Price | Recommendation |
|---|---|---|---|---|
| RTL-SDR Blog V4 | 500 kHz – 1,75 GHz | 2,4 MHz | ~40 EUR | Beginner — best choice |
| AirSpy Mini | 24 – 1800 MHz | 6 MHz | ~100 EUR | Advanced |
| AirSpy R2 | 24 – 1800 MHz | 10 MHz | ~180 EUR | Semi-pro |
| SDRplay RSP1C | 1 kHz – 2 GHz | 10 MHz | ~130 EUR | Wide range |
| HackRF One | 1 MHz – 6 GHz | 20 MHz | ~350 EUR | Transmit + receive |
SDR# vs SDR++
📺 RTL-SDR + SDR++ quick setup Windows (2023) — drivers, Zadig, first reception
| Criterion | SDR# | SDR++ | Recommendation |
|---|---|---|---|
| Operating system | Windows only | Win / Linux / macOS | SDR++ more flexible |
| Getting started | Very easy, many tutorials | A bit steeper | SDR# for absolute beginners (Win) |
| Multi-VFO | No | Yes | SDR++ clearly better |
| Performance | Good | Very good (less CPU) | SDR++ more efficient |
| Active development | Slower | Very active | SDR++ more modern |
Reception projects — overview
FM radio Getting started
87,5–108 MHz, Modulator: WFM, Bandbreite: 200 kHz, Gain: 30–40 dB. Der einfachste Test ob alles funktioniert.
ADS-B aircraft 1090 MHz
Every aircraft transmits position, altitude and speed on 1090 MHz. Display it on a map with dump1090 or the FR24 plugin.
AIS ships 161/162 MHz
Channel A: 161.975 MHz · Channel B: 162.025 MHz · modulation: GMSK · decoder: AIS plugin or aisdeco2.
NOAA weather satellites 137 MHz
NOAA 15/18/19 transmit APT images at about 137 MHz. Software: WXtoIMG or noaa-apt. Antenna: V-dipole, 53 cm per rod.
Aviation ATC AM
108–137 MHz, modulation: AM, bandwidth: 8–10 kHz. Emergency frequency: 121.500 MHz. Current frequencies: airportcodes.org
TETRA spectrum View only
380–400 MHz, NFM 25 kHz. Characteristic burst patterns visible in the waterfall. Content encrypted and not decodable (TEA2).
Recognising TETRA in the spectrum
TETRA signals can be spotted in the SDR spectrum — you can see them but not decrypt them: