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| The Antenna
According to Wikipedia, an antenna is a transducer designed to transmit or receive electromagnetic waves. In other words, antennas convert electromagnetic waves into elecrical currents and vice- versa. Antennas are used in systems such as radio and television broadcasting, point-to-point radio communication, wireless LAN, radar and space exploration. Antennas usually work in air or outer space, but can also be used under water or even through soil or rock at certain frequencies for short distances.
Physically, an antenna is a series of conductors that generate an electromagnetic field in response to an applied alternating voltage and the associated alternating electrical current, or can be placed in an electromagnetic field so that the field will induce an alternating current in the antenna and a voltage between its terminals. Next to your rig the antenna is the most important part of your ham radio set up. A good antenna will produce good results whist a bad or poorly maintained antenna will leave you struggling to hear anything at all. It is worth investing time and money on your antenna sytem. There are many types of antennae ranging from long wires, dipoles and verticals, to complex beams mounted on towers ,parabolic dishes and horns. They all have different properties and uses. What you chose to erect will depend upon your specific interests and, in the case if HF operators in particular, the mount of real estate available to you. Whilst on the question of real estate, don't forget, large antenna structures may require planning permission before they can be erected. You should check this out with the appropriate authorities in your area.
Posted 30 August 2010 12:45:15 GMT | |
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