Information AboutGuy-wire |
| CATEGORIES ABOUT GUY-WIRE | |
| cables | |
| guyed masts | |
| wind power | |
| ship construction | |
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A guy-wire or '''guy rope''' is a metal wire used to aid stability in tall structures (frequently Radio Masts ). It is attached to the structure on one end and the ground on the other. They are almost universally used in counter-balancing sets or pairs, with one wire on one side of the structure, and one on the other side. A guy-wire is often placed at the end of a string of power poles to counterbalance the pull of the wires. Roof Antennas are usually held up by three guy-wires. On some high structures flight safety markers in the guys are necessary. For chimneys and masts for VHF -/ UHF -transmissions or non-transmission use only, the mechanical properties of the guys are important. This is not the case for mast antennas, for masts with aerials for VLF , LF , MF , and SW or for masts situated close to such aerials. GUYS FOR MAST ANTENNAS Special attention must be paid for guys of mast antennas. Guys of Conductive Materials such as metals and that are longer than one-fifth of the radiated Wavelength can have a strong influence of the Radiation Pattern , especially when used as a mast antenna or carrying an aerial for VLF, LF, MF, and SW. Guy wires also sometimes interfere when situated close to such a site. On most mast antennas steel guys are used. The guys are divided by Insulator s into multiple sections, each smaller than one-fifth of radiated wavelength. Steatite is often used for these insulators. The individual sections of the guys can develop large charges of Static Electricity so on tall masts very large insulators are required. For overvoltage protection in case of Lightning strikes, Lightning Arresters are required at the insulators. The insulators must be maintained carefully, as an insulator failure can lead to mast collapse. Some newer mast antennas are fit with insulators at the mast construction and are Grounded via coils, which are situated next to the anchor blocks at which the guys are fixed on insulators. In some cases it is possible to ground the guys directly at the anchor blocks. This is only possible if the guys do not disturb the radiation pattern of the mast antenna. On some mast antennas guys of non-conductive Polymer s are used. Although these guys alleviate some of the problems associated with mast antennas they are rarely used as they are not as durable and long lasting as metal guys. On antennas for longwave and VLF, the guys may serve an electrical function, either for Capacitive Lengthing of the mast or for feeding the mast with the radiation power. In these cases, the guys are fixed without an insulator on the mast, but there is at least one insulator in the guy if necessary. If guys are used for feeding the mast with high frequency power it is often possible to use a grounded mast. The power to the guys is fed via conductor ropes running from the tuning unit to the feed point on the guys. GUY STRUCTURES A list of famous guyed structures can be found on List Of Masts . There are also stuctures, which consist of a free standing bottom and a guyed top. SEE ALSO |
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