Lookslike,thisisaswitchingpowersupply,the"bad"frequency"fromyourpicare160K,320Kandaround640K.They'renarrowBand.Iguessyourprimaryswitchingfreqisaround80Kor160K.Thus,youneedtoimproveyourprimarydesigntokillthislowfreqspur.WithoutSchematic,Idon'tknowhowtoimproveit.Asfarasthe8MHz,itiswideband,trytousealargercommonchokeatACinputside,andseeifitworks.