Extended Double Zepp Yagi Antenna

摘要

The Extended Double Zepp favors two opposite directions. The basic Extended Double Zepp center-fed antenna consists of two 0.62 wavelength sections placed end to end (1.24 wavelengths total) and fed in the middle. The antenna has a pattern broadside to the wire with one major forward and one major backward lobe, each having about 3 dBd gain at the cost of narrow beamwidths in the main lobes. That specific length maximizes the gain and has a feed point impedance that is easily transformed to 50 Ω by a well-chosen segment of ladder line. But, if you want only one direction, consider my Extended Double Zepp Yagi. I decided to add the reflectors to concentrate the pattern from my San Francisco, California location toward Alabama, the location of my childhood friend Junior, N4CLT, with whom I enjoy chats every Saturday morning, and toward the Caribbean and South Africa.