Antenna 005: MultiBand Dipole Author: Frederick R. Vobbe, W8HDU January 5, 2008 |
Different band dipoles can be put together with a single feed. For example, in figure 1 below we see that we're feeding a single line to (2) dipoles, one on 40 meters, and one on 15 meters..
As seen above, one wire would be run in one direction, while the other would be at a right angle. For example, the 40 meter wire would run north and south, and the 15 meter wire would run east and west. Therefore the main lobe of the 40 meter signal would radiate to the east and west, while the 15 meter signal would radiate to the north and south. As was explained in the article on Inverted Dipole, you can droop the ends down as shown below in figure 2.
One thing to keep in mind is that when dropping the ends of the wire down, it has a tendency to cause more of a scattering of the RF pattern. If the support pole in the center is metal, and grounded, it could cause some vertical patter distortion. Frederick R. Vobbe, W8HDU |
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