[sailnby]

Aerosail, The ferrite beads, RF chokes, torrodials and whatever other noise suppresion devices will work if the noise is coming through the power source, however as Jeff eluded this sounds as if it is radiated. Without specifics I''m unsure what to suggest other than re-orienting the Icom and all mic cables as a test. There are meshes and enclosures that can all but eliminate radiated interference.