Ferrite Balun Cores are used for matching unbalanced coaxial transmission lines or systems to balanced two-wire lines or systems. They are also known as balanced converters; bazooka; line-balance converters. These cores are used in devices that connect balanced line to unbalanced lines; for instance, a twisted pair to a coaxial cable. A balanced line is one in which both wires are electrically equal. In an unbalanced line, such as a coax, one line has different properties than the other.