6. What type of ground (screen) is required?
For all but very specialized applications, Valcom recommends 36 radials of #10 copper wire each 100 feet long and terminated with a 5 foot grounding rod. The radials are joined to a central ring made up of four quadrant sections which are assembled on site to encircle the base mounting structure of the antenna. The connection to the tuning unit or transmission line is made via four heavy copper wires. The radials are normally buried approximately 12 inches deep. A good quality ground screen is strongly recommended for efficient operation of the antenna. It reduces power losses in the earth near the antenna where current concentrations are the highest. It also provides a convenient connection means for the tuning unit which is usually located at the base of the antenna.
απο εδω
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