| Abbreviation | Definition |
|---|---|
| AISG | Antenna Interface Standards Group |
| AJD | All Japan Districts |
| AK | Atwater-Kent radio |
| ALD | Antenna Linkage Device |
| AM-10 | AMSAT Oscar-10 AMateur SATellite |
| AMBCS | Alaska Meteor Burst Communications System |
| AMBE | Advanced Multi-Band Excitation |
| AMRPTR | Amateur Repeater |
| ANARC | Angel of the North Amateur Radio Club |
| ANARC | Association of North American Radio Clubs |
| APO | Advanced Planner Optimizer |
| APRS | Automatic Packet Reporting System |
| APRS | Automatic Position Reporting System |
| APRS | Automatic Position Reporting System (original term - now Packet instead of Position) |
| AR | Amateur Radio |
| ARC | Advance Radio Car |
| ARC | Amateur Radio Club |
| ARCF | Amateur Radio Christian Fellowship |
| ARCI | Amateur Radio Club International |
| ARDF | Amateur Radio Direction Finding |