What was found
BDL TO BWI - FLIGHT 3892 EN ROUTE - THE CREW NOTICED SMOKE COMING FROM THE RADAR UNIT. THE FLIGHT WAS DIVERTED TO ACY. AN EMERGENCY WAS DECLARED AND EMERGENCY EQUIPMENT CALLED. ALL PAX DEPLANED THROUGH MAIN CABIN DOOR. THE SMOKE WAS VERIFIED AS COMING FROM THE RADAR INDICATOR.. THE UNIT WAS INOP PER MEL REQUIREMENTS. SUBSEQUENTLY THE UNIT WAS REMOVED AND REPLACED. OPERATIONAL CHECK GOOD.