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A gin pole in use loading logs A gin pole used to install a weather vane atop the 200-foot steeple of a church Roof trusses being assembled with gin poles. A gin pole is a mast supported by one or more guy-wires that uses a pulley or block and tackle mounted on its upper end to lift loads. The lower end is braced or set in a shallow hole and ...
A sailboat's mast is supported by shrouds (side-to-side) and stays (fore-and-aft) – nautical equivalents of guy wires.. A guy-wire, guy-line, guy-rope, down guy, or stay, also called simply a guy, is a tensioned cable designed to add stability to a freestanding structure.
Guyed masts are frequently used for radio masts and towers. The mast can either support radio antennas (for VHF, UHF and other microwave bands) mounted at its top, or the entire structure itself can function as a mast radiator antenna (for VLF, LF, MF). In the latter case, the mast needs to be insulated from the ground. Guyed radio masts are ...
The antenna used for broadcasting through the 1920s was the T-antenna, which consisted of two masts with loading wires on top, strung between them, requiring twice the construction costs and land area of a single mast. [2] (pp 77–78) In 1924 Stuart Ballantine published two historic papers which led to the development of the single mast antenna.
A modified mast antenna, usually grounded at its base, augmented by one or several parallel wires called "skirt wires" that attach to the mast part-way up the antenna. The skirt wires can attach at any height between part-way up and the top of the mast. One or more of the skirt wires is fed with the signal, similar to a gamma match.
The antenna must be very large at the VLF frequencies used; the supporting masts are 250–300 metres (820–980 ft) high, and the topload is about 1,900 metres (6,200 ft) in diameter. The trideco antenna was developed for high power naval transmitters, which transmit on frequencies between 15 and 30 kHz at powers up to 2 megawatts, to ...
Often (see pictures) the ground plane rods are sloped downward at a 45-degree angle, which has the effect of lowering the main lobe of the radiation pattern so more of the power is radiated in horizontal directions, and increases the input impedance for a good match to standard 50-ohm coaxial cable. To match 75-ohm coaxial cable, the ends of ...
Goliath transmitter was a very low frequency (VLF) transmitter for communicating with submarines, built by Nazi Germany's Kriegsmarine navy near Kalbe an der Milde in Saxony-Anhalt, Germany, which was in service from 1943 to 1945.