![]() ![]() Steel wire also should be avoided if possible. Since we are dealing with "skin effect" properties, just the outer coating will bear the RF energy. One of the best, and probably the cheapest is the electric fence wire that is coated with brass, or copper. It does NOT radiate RF energy well, and doesn't receive signals from other amateur stations transmitting to you. When subjected to the weather, mechanic wire will rust easily, creating a never ending problem of either breakage, or a problem of MAJOR non-connectivity. The least favored is the mechanic wire, which has a high resistance, and corrodes and rusts easily, causing unwanted resistance, and antenna failure. Any good conductor of electricity will conduct RF. Of course, none of us will be using any precious metals in making an antenna, but the rare metals, gold, silver, and platinum are the three most conductive metals of all, but since they cost so much, we have to settle for copper wire, steel with either a brass, or copper coating, or perhaps tin, with or without copper coating, or plain electric fence type tin wire, or possibly aluminum wire if you have no other wire to use. The type of metal used would have a conductivity scale. RF though, would be along the outer portions of the wire, like the skin of the wire. AC and DC currents would be from the center out. If we could see the wire with the current on it, it would be easy to define. Picture if you will, a wire with the cut portion of the wire pointing at you. ![]() Regular DC or AC current and voltages travel through the center of the wire, whereas RF runs on the outer portions of the wire. If you plan on building several antennas, you should have no problem with this large roll of wire. The only draw back is that you have to purchase it in either 1⁄ 4 or 1⁄ 2 mile (0.4 or 0.8 km) rolls. Tin wire, used for electric fence purposes make an excellent wire antenna, and it is not to expensive. Its not hard to work with, and is probably the best antenna metal. Diameter of 12 gauge wire is about 1/8th inch thick. Finding old house wire is the best choice. Copper house wire prices have skyrocketed in the recent months. Aluminum wire is not expensive, but it is the least desirable wire for antenna use. Aluminum antenna wire is hard to work with, has a very easy breaking point, and oft times, stretches out of shape, and cannot be soldered using conventional solder. Metals such as copper, aluminum, tin, and steel all will conduct electricity, but when we are talking about Radio Frequency, or RF currents and voltages, we are talking about "Skin Effect" electricity. Remember that you should use metal of similar nature, as dissimilar metals have a tendency to corrode, or to have a non-conductive properties. Antennas can be made from many different materials. AGM batteries are spill proof, can be used in rugged environments, charge faster and have a much longer life to name a few.Use materials that match easily. AGM batteries are superior to flooded batteries in a number of ways. The AGM design holds the electrolyte in suspension and keeps the electrolyte in constant contact with the lead surface on the plates. I keep an Optima Blue Top high performance AGM (sealed absorbed glass mat) battery on a CTEK Battery Minder Charger in the Ham Shack. ![]() TI – radio ampere rating in transmit mode. ![]() RI – radio ampere rating in receive mode.%BAh – 75% of total battery ampere hour usage.Plug in your own numbers and check your results.įormula: %BAh / ( ((R%h x RI) + (T%h x TI)) = rt I have examples of the formula with both a 100 watt and 10 watt transceiver below. Draining 100% of a battery is obviously unworkable so transceiver run time is calculated at 75% of total battery amp hours. The formula has been a fairly accurate way to estimate my shack’s backup battery consumption. Somewhere in my travels across the Internet I ran into a formula for calculating transceiver usage and associated battery consumption. ![]()
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