Fan Dipole Antenna
The SMC multifrequency antennas are designed to give a low cost compact antenna for short to medium range omnidirectional or bidirectional coverage on up to four spot frequencies in the HF band.
The SMC/MCFD/N is designed for installations where two masts can be used, while the SMC/CFD/N is a more economical version using only one mast. Both antennas use the CCJ/1 coaxial cable junction unit which has a built-in suspension point for the coaxial downlead, so ensuring that the weight of the cable is not taken by the termination. The antennas are designed for fixed or temporary location, and are constructed of high quality components. The elements are of multistrand hard drawn copper magnesium fitted with line taps and end insulators.
Several versions are available with the number of elements normally equal to the number of spot frequencies required. Some coupling between elements will occur, which affects the VSWR, so final adjustment can be made on site quite simply by adjusting the line taps on the ends of each element. For this reason the elements are supplied cut over-length.
All installations are delivered complete with halyard strops, D shackles, insulators, and the CCJ1 junction unit which can have UHF type N or any other termination to order. Coaxial cable to customers' requirements complete with connectors. Masts for light or heavy duty, lighting kits to ICAO standards and mast erection equipment are all available. For economical installations we would recommend the PA2 alloy mast or the telomast. Where antennas are to be used in extreme environments we would recommend the SMC galvanised tubular or lattice steel masts. Details of these can be obtained on application from the Antenna Systems department of SMC.
|Frequency Range||2-30 MHz (2, 3 or 4 spot frequencies (as a long wire antenna).|
|VSWR||Normally better than 2:1|
|Power Rating||Up to 1kW|
|Azimuth Radiation||Depends on frequency and height of antenna.|
|Input Impedance||50-75 ohm depending on design height.|
|Antenna elements||7/0.914mm (7/036") or 7/1.118mm (7/044") hard drawn copper strand|
|Insulators||Carbon loaded ultra violet resistant polypropelene|
|Metalwork||Stainless steel or plated brass|