What was found
UPON RAISING GEAR AFTER TAKEOFF, GEAR WARNING HORN SOUNDED CONTINUOUSLY. RECYCLED GEAR SEVERAL TIMES, BOTH CLEAN AND FLAPS 15. CYCLED THROTTLES UP AND PUSHED HORN OFF BUTTON, HORN CEASED. FLIGHT CONTINUED TO MSP AND LANDED WITHOUT INCIDENT. MAINTENANCE CHANGED THROTTLE SWITCH PACK FOR RIGHT THROTTLE, OPERATIONAL CHECK OK.