Software defined radio is a bit like having one of those old ham radio’s, only at a fraction of the price. The USB dongle costs so little it’s really worth it just to have a look, and there are so many things to do with this fun device.
Hardware:
Software:
https://www.rtl-sdr.com has a selection of software.
Being an Ubuntu user, I went with the one pictured above, gqrx. Here is the install tutorial I followed: https://ranous.files.wordpress.com/2020/05/rtl-sdr4linux_quickstartguidev20.pdf
So far I have been able to pick up AM and FM radio stations, as well as having a look at the WiFi band, and receive my son’s toy walkie talkie and RC car transmitters.
Apparently with the right aerial, you can receive GPS and even Weather Satellite information with these things. Not to mention your local CB radio channels. A great learning experience. Go buy one, they are less than $10.