So, you know how you have a toy walkie-talkie that you use to talk to your friends? Well, Tucson Amateur Packet Radio is kind of like that, but for grown-ups who really love talking to each other using radios.
They use something called "packet radio" which is like sending messages back and forth using a secret code that only they can understand. They also use special radios that can send and receive these messages over long distances, kind of like a super-powered walkie-talkie.
The "amateur" part means that they do this as a hobby, just for fun, and not for their job. And they're in Tucson, which is a place in Arizona where lots of people love doing this kind of thing.
So, in summary, Tucson Amateur Packet Radio is a group of hobbyists who love using special radios to send secret messages over long distances, all for fun!