The basic requirements for obtaining high-accuracy direction of arrival information in VHF/UHF frequency range have become a complex system problem in recent years. Today's operational requirements specify direction finding systems that must operate over several octaves of bandwidth and provide RMS bearing accuracies of one degree or less. In addition, the overall system must handle low level and short duration signals with high probability of intercept, as well as providing unambiguous direction of arrival information over relatively large spatial fields of view. Significant advancements have recently occurred in the development of VHF/UHF direction finding systems that result in both high performance and cost effectiveness. This work aims at designing and building a direction finding system to estimate the azimuth angle of arrival of a known frequency signal. The proposed system brings together time difference of arrival (TDOA) interferometry and the use of microprocessors in a distributed processing system to provide high bearing accuracy over the 100-400 MHz frequency range. The system includes both hardware and software parts. The system is PC based with high level software that allows full control and monitoring of the system through an easy to use visual user interface panel built up using visual programming techniques. Therefore, hardware-oriented TDOA interferometry techniques, used in the past have been replaced with software oriented techniques. A proper calibration model has been developed to compensate the hardware tolerances and mismatching.