| KBAJ-FM | |
| City: | Deer River, Minnesota |
| Area: | Iron Range |
| Branding: | J105 The Thunder |
| Frequency: | 105.5 MHz |
| Airdate: | 1999 |
| Format: | Classic rock |
| Erp: | 100,000 watts |
| Haat: | 155m (509feet) |
| Class: | C1 |
| Facility Id: | 26005 |
| Affiliations: | ABC News Radio |
| Sister Stations: | KMFY, KOZY |
| Owner: | Scott Hennen and Steven Hallstrom |
| Licensee: | Rapids Radio LLC |
| Webcast: | Listen Live |
| Website: | J105 Online |
| Licensing Authority: | FCC |
KBAJ (105.5 FM, "J105 The Thunder") is a classic rock radio station licensed to Deer River, Minnesota, and is owned by Scott Hennen and Steven Hallstrom, through licensee Rapids Radio LLC.
The radio station went on-air in 1999. Originally owned by Red Rock Radio Corp., it was a KQDS-FM simulcast. On January 1, 2017, KBAJ was sold by Red Rock Radio Corp. to Lamke Broadcasting and rebranded as "J105 The Thunder", still keeping the classic rock format.[1] The sale, at a price of $200,000, was consummated on March 1, 2017.
On November 1, 2021, the station and its sister stations were sold to Steve Hallstrom and Scott Hennen, branding themselves as Rapids Radio.
In the winter of 2017, KBAJ became the broadcast home for championship Grand Rapids High School hockey.
KOZY and KMFY are also owned by Rapids Radio.