Amateur Radio Callsigns in ZIP Code: 21155
| Callsign | Name | City | State | Country |
|---|---|---|---|---|
| K3AJ | VALENTI, THOMAS W | Upperco | MD | United States |
| K3OUD | MARSH, BERNARD R | UPPERCO | MD | United States |
| KA3ZAL | Johns, Anthony S | Upperco | MD | United States |
| KE3RI | FOWBLE III, WILLIAM A | UPPERCO | MD | United States |
| W3GQY | FELDMAN, CHARLES | UPPERCO | MD | United States |
| K3DB | BOLLINGER, DAVID A | UPPERCO | MD | United States |
| KC3HND | SMALL, ALASTAIR W | UPPERCO | MD | United States |
| AC3CQ | Kelley, Michael S | Upperco | MD | United States |
| KC3LGQ | Kaskel, Lawrence T | Upperco | MD | United States |