This specification covers the design, fabrication and testing necessary for the manufacture of Test Set, Telephone,TS-3647/G. This test set is also known as the Cable Orderwire Unit(COU) and is one of the electronic units comprising the Digital Group Multiplexer(DGM) family of cable system equipments developed by the Joint Tactical Command, Control and Communications Agency
(JTC3A, formerly TRI-TAC). See 6.1 for intended use of the TS