This report (Contract No. H0220073) describes the development, laboratory testing, and intrinsic safety testing of a full-wave location transmitter. The primary objective was to obtain as rapidly as possible an electromagnetic transmitter and receiver system for use in locating trapped miners. Since the transmitter would be used in coal mines, intrinsic safety was an important consideration. Other factors considered in the design included size, weight, cost, operating life, and ease of deployment. A miner's lamp battery was to be used as the source of prime power. Two basic location systems, a continuous wave system and a pulse- type system, were designed, fabricated, and field tested. Subsequently, a new design concept, using four switching transistors to obtain full-wave drive to a resonated loop antenna, was developed.