A software-defined radio (SDR) is a small box that turns radio waves into data your computer can tune. Plug in an antenna and you can hear shortwave broadcasts, aircraft, ships and amateur radio. Before buying one, try listening through other people’s receivers on Skywave DX: it shows you what shortwave sounds like from a good antenna, for free.

RTL-SDR Blog V4: the cheapest way in

A USB stick that tunes from about 500 kHz to 1.766 GHz. Its built-in upconverter covers shortwave up to 28.8 MHz, so the bands in our band guide are in reach without extra hardware. It’s the usual first receiver: modest on crowded shortwave bands, excellent value above 30 MHz (aircraft, weather satellites, FM).

SDRplay RSPdx-R2: one box for everything

Covers 1 kHz to 2 GHz with up to 10 MHz of spectrum on screen at once, and has three antenna inputs (two cover the full range, one goes up to about 200 MHz). A good step up if you want strong shortwave performance and VHF/UHF in one receiver.

Airspy HF+ Discovery: built for shortwave

Covers 0.5 kHz to 31 MHz, plus 60 to 260 MHz. It concentrates on HF, where its strength is handling weak stations next to strong ones, exactly the situation on a busy evening shortwave band. A favourite with serious shortwave and medium-wave DXers.

KiwiSDR 2: a receiver for the whole world

Covers about 10 kHz to 30 MHz and works differently: it runs its own web server, so up to several people can listen through it at once from a browser. The receivers Skywave DX tunes are KiwiSDRs run by hobbyists who share them. If you have a quiet location and a good antenna, running one is a way to give back.

Which one?

  • Just curious: listen online first (how), then an RTL-SDR Blog V4.
  • Mainly shortwave and medium wave: Airspy HF+ Discovery.
  • Shortwave plus everything above it: SDRplay RSPdx-R2.
  • Want to share your antenna with the world: KiwiSDR 2.

The antenna matters more

Any of these will disappoint with a short wire indoors next to a computer. Electrical noise from chargers and LED lights drowns shortwave. A wire outdoors, away from the house, does more for reception than a more expensive receiver. Specifications here are from the manufacturers’ published data; check the current model before you buy.