need help with amp supply 550 n/t ,has 3 -3-500,s. works fine on 10/15/20/40/ but comes to (80) tunes to 1500 in fm and then quickly falls back. can you help. could it be the filament choke?? or what. all other bands up to par. thanks lloyd. n4wpg1@peoplepc.com. or 601-774-2721 or do, you have a full schematic of this beast??? 