Издательство: | Книга по требованию |
Дата выхода: | июль 2011 |
ISBN: | 978-6-1346-9539-8 |
Объём: | 84 страниц |
Масса: | 147 г |
Размеры(В x Ш x Т), см: | 23 x 16 x 1 |
Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. A random wire antenna (or long-wire antenna) is a radio frequency antenna consisting of a wire whose length does not bear a relation to the wavelength of the radio waves used, but is typically chosen more for convenience. This type of antenna sometimes is called the zig-zag antenna, as it may be strung back and forth between trees just to get enough wire into the air. For example, an antenna for 3MHz might be 20 m (66 ft) - 40 m (131 ft) long. Such antennas are usually not as effective as antennas whose length is adjusted to resonate at the wavelength to be used. They are widely used as receiving antennas on the long wave, medium wave, and short wave bands, as well as transmitting antennas on these bands for small outdoor, temporary or emergency transmitting stations, as well as in situations where more permanent antennas cannot be installed.
Данное издание не является оригинальным. Книга печатается по технологии принт-он-деманд после получения заказа.