[mpumas]

Could be the radio, antenna lead or the antenna. To determine if it is the radio, disconnect the antenna at the radio and insert a 5 ft piece of insulated wire with about 1/4 inch of the insulation stripped off in the antenna hole at the radio. You should be able to hear an increase of noise and stations. If it works, disconnect the antenna lead at the antenna and do the same with the wire but touch the antenna lead. If it works there, it is the antenna which can be disassembled and cleaned. Honda uses capacitance coupling between the antenna lead and the antenna, so it doesn't take much to kill the signal if the nylon lifter rod is covered in dirt and grease.