SDR websites:
https://www.rtl-sdr.com/techminds-using-public-online-sdrs-without-sdr-hardware/
http://www.websdr.org/
https://www.remotehams.com/
https://rx-tx.info/map-sdr-points
https://www.openwebrx.de/
http://kiwisdr.com/public/
https://ve3sun.com/KiwiSDR/