In a typical HF setup, the car is capacitively coupled to the ground, so the antenna is something sort of like a cross between a lopsided vertical dipole (with the whip being one side and the car the other) and a vertical with elevated radial system. Product Distributed by: Ohio Valley Lightning Protection, Inc.
ampacity) to discharge lightning and fault currents into the ground. Copper wire offers high fusing current (see section on fusing current vs. for many decades as the standard grounding conductor in substations, transmission, generation and distribution systems. How do mobile HF operators get RF grounds? For obvious reasons, the 8-foot buried pole won't work. Copper wire and cable have been used in the U.S. A "current" or "choke" balun is most commonly used for this.Ģ. If you use a "complete" antenna like a dipole or a ground plane (that is, one that doesn't require your feedline to connect to ground), you don't need a RF ground, as long as you keep common-mode currents off your feedline. The requirements for various other end-fed antennas depend on their length. A ½ wavelength base-fed vertical needs only a very modest ground, and a ground rod is adequate. If it's longer, you can get by with fewer. If your antenna is much shorter than ¼ wavelength, you'll need many, many radials to get reasonable efficiency. Chapter 8 of the ARRL Antenna Book shows the approximate trade between resistance and number of radials. A ground rod will help a little, but the RF resistance will be high, resulting in quite a bit of loss. A few radial wires will provide a moderately low loss connection. The connection to ground has to have a low RF resistance, or you'll expend too much of your power heating the ground. One wire of the feedline connects to the base of the antenna, and the other connects to ground. Insert one of the ground rods, if its feasible, near the electrical ground for the house electrical system. A quarter-wave vertica is a popular example. This is required only for some antennas- ones which require current flow to ground to complete the antenna circuit. See the TIS Page on Lightning Protection.Ĭ. The requirements for a ground for lightning protection are much more stringent than for a safety ground as a lot of energy must be safely dissipated. The safety ground conductor in your wall sockets should be connected to ground according to this code, and your rig's chassis should be connected to the safety ground.ī.
#LIGHTNING GROUND ROD CODE#
I believe that most states adopt the National Electrical Code (NEC). The requirements for this ground are spelled out in your state's electrical code. This protects you from a shock hazard if one of the mains or high voltage power supply wires contacts the chassis due to some kind of fault. The best ground for one function isn't necessarily the best for another. Grounds fulfill three distinct functions. How important is a ground? Most people say that grounding is all- important, but I have had a few people tell me that grounds aren't necessary.
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