Beyond voice
Talking is only part of it. A lot of operators spend most of their time sending things other than speech.
Digital modes
Connect the radio to a computer or phone and it can send data. Some digital modes are so efficient that a signal too weak for you to hear will still be decoded perfectly, which means you can work the world on a few watts and a wire. Others carry keyboard-to-keyboard chat, or e-mail-style messages over radio when there is no internet.
Morse code
No longer required for any licence, and still going strong - because a Morse signal punches through noise and interference that would bury a voice. It is a skill you learn over months, like an instrument, and there are clubs and slow-speed nets specifically for learners.
Pictures and video
Slow-scan television sends still images over an ordinary voice channel - it sounds like warbling and comes out as a photograph. Some operators do full live video on the higher bands, and the International Space Station periodically transmits slow-scan images that anyone with a handheld and a bit of wire can receive.
Satellites
There are amateur satellites in orbit that anyone with a Technician licence can use. A handheld radio and a small directional antenna held by hand are genuinely enough to talk hundreds of miles through one as it passes overhead. Free software tells you when the next pass is.
Bouncing signals off things
- The moon. Point a big antenna at it, transmit, and hear your own echo 2.5 seconds later. People make contacts this way.
- Meteor trails. Brief ionised trails reflect signals for a second or two - long enough for a short digital exchange.
- The upper atmosphere. The everyday one: shortwave signals bounce off the ionosphere and come down thousands of miles away.
Building and measuring
The amateur licence lets you build and modify your own transmitters, which almost no other radio service allows. People build antennas, small low-power transmitters, digital interfaces and test equipment - and many turn that into a career.