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Channel Jumper wrote:
Radials on a elevated antenna only works if the radials are placed at or near the bottom of the antenna and are arranged at a 45* angle. Any other angle and you might as well not have any radials at all! Utter nonsense. The radials do have to be at or near the bottom but the angle of the radials mostly determines the antenna impedance. With the radials at 90 degrees the impedance will be around 40 Ohms and at 45 degees very close to 50 Ohms. One can download the demo version of EZNEC and observe the effect of radial angle for themselves. On a 10 -12 meter antenna, these radials would need to be at least 1/4 of a wavelength long - 9 feet and preferably 18 feet long to do any good! The ideal radial length for ANY ground plane antenna is slightly longer than 1/4 wavelength, no matter for what frequencey. If you coil them up they do not work as intended, but they might help a little. If you coil them up, you are inductively loading them, shortening the physical length just like a loaded vertical. If you make them electrically around 1/4 wavelength, loaded radials will work just fine. Ground plane antennas have been made with 4 hamsticks; 1 for the vertical element and 3 for the radials and they work. They major drawback to such is the limited bandwidth of loaded antennas. snip remaining babbling nonsense -- Jim Pennino |
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