- WebSDR.org - Global network of publicly accessible SDR receivers
- KiwiSDR Network - Interactive map of KiwiSDR receivers for HF/VHF/UHF monitoring
- Global Tuners - Network of remotely controlled radio receivers worldwide
- SDRangel - Open-source SDR transmit/receive application with wide hardware and mode support
- RTL-SDR.com - News, tutorials, and project hub for RTL-SDR and other SDR hardware
- SIGIDWiki - Collaborative wiki for identifying unknown radio signals via audio and waterfall samples
- Radio Garden - Interactive global map of radio stations
- Numbers Station Research & Archive - Database and live schedule of known number stations
- HF Underground - Logs of pirate, utility, and number station receptions
- Enigma 2000 - Community focused on identifying and cataloging mysterious radio signals
- Broadcastify - Live police, fire, EMS, and aviation feeds worldwide
- LiveATC.net - Global live streams of air traffic control communications
- MarineTraffic Radio (AIS Feeds) - Marine AIS transponder data and related VHF radio info
- QRZ.com - Amateur radio callsign database and operator lookup
- APRS.fi - Live map of Automatic Packet Reporting System (APRS) stations and trackers
- FCC Licensing Databases - US radio license lookups, linking callsigns to registered license holders
- N2YO.com - Live satellite tracking and radio frequency info
- SatNOGS Network - Global open network of satellite ground stations
- Heavens-Above - Satellite pass predictions and amateur radio satellite data
- Frequency Database - Comprehensive global frequency listings and live feeds
- High Frequency Coordination Conference - Official frequency schedules of shortwave broadcasters
- EiBi Shortwave Database - Regularly updated international shortwave schedules
- Reddit Shortwave - Shortwave Reddit Thread
- HF Underground Forums - Underground radio forum
- Worldwide Radio Forum (WRTH) - Radio Forum
- SWLing Post - Active shortwave listening community blog with schedules, gear reviews, and reception reports