With increased use of the Internet and mobile communications has come the need to transmit digital information at higher speeds. This need has put new requirements on transformer manufacturers and presented new challenges to test equipment designers. This paper looks at the new measurement requirements and provides a technical overview. The measurements looked at in this paper include; Total Harmonic Distortion (THD), Insertion Loss (IL), Return Loss (RL), Longitudinal Balance (LB) and Transverse Balance (TB).