A modified Purcell linear array was designed and built for the 35-gc band. A novel analytical technique was developed that promises to yield design data sufficiently precise for even very long arrays. Computer techniques were developed for designing linear arrays with widely and variably spaced elements. The problem of finding the optimum spacing for the elements in an array of isotropic elements was set up precisely, and solutions found for 2 cases. Beam- broadening modifications were studied for six leaky-wave antennas. A doubled- layered pillbox antenna was designed and built that has wide-band operation, no aperture blocking, and low-side-lobe patterns. Three types of wide-band omniazimuthal direction finding antennas were built and tested.