2rotorsrule, We ran a 2002 Claas Mega 204 in Australia in the harvest just gone and had the same problem with reception for both AM and FM stations. The AM stations could not be recieved if the combine was facing the wrong way, and the Transmiters are only about 20 miles away. FM was a bit better but not much. The radio_cd player is a Kenwood, great unit fitted in Australia, however the antana is german made (about 12 inches in height and plastic coated) and fitted in the Claas Harsewinkel factory, they had fitted a ground wire to it. Not worth a pinch of! After putting up with it for a few days, pulled it out and fitted an all metal antana that extends to about 4 foot in length. I ran the existing earth lead on this antana aswel, it is mounted in the same place as the old one on the ladder side of the cab roof. Now can pick up AM stations 150 to 200 miles away, FM reception is good aswel. We ran a Claas 203 before the 204 and it had the long metal antana fitted, however we changed the mounting site to a metal bracket behind the cabin worked well.