Listening to police and fire calls used to be a pretty simple proposition: buy a scanner, punch in some frequencies — or if you’re old enough, buy the right crystals — and you’re off to the races. It was a pretty cheap and easy hobby, all things considered. But progress marches on, and with it came things like trunking radio and digital modulation, requiring ever more sophisticated scanners, often commanding eye-watering prices.
This is a companion discussion topic for the original entry at https://hackaday.com/2024/02/10/pi-5-and-sdr-team-up-for-a-digital-scanner-you-can-actually-afford/