You'll need the K2/100, of course. Then you key the amp with the PA Key out (RCA Jack) connection on the rear panel of the KPA100. Easy. de Joe, aa4nn ----- Original Message ----- From: "William Langford" <langford at graceba.net> If I build the K2, how could I key my Ameritron ALS-600 amp? Is anyone out there driving an amp with their K2? Thanks K4DT