How high should I put my antenna?
I hear a lot of talk about antennas and get a lot of questions, most of which do not have simple answers. One such question is the height of antennas. This pertains to horizontal antennas and I tried to make it simple and still be fairly accurate. That is hard. Since the height of the Ionosphere varies from about 250km to 400km we do not know exactly what the optimum radiation angle needs to for any given distance but we do know the range of angles for any given distance (assuming one hop).we know that the main lobe of any properly installed horizontal antenna is only determined by height above ground. The most effective radiation angles are also above and below the so-called radiation angle at the 3dB points. Consequently we can say that, in general, the best height for zero to 200 miles is 1/4 wave high, the best height for 125 to 560 miles is 3/8 wave high, and the best height for 250 to 1250 miles is 1/2 wave high. Obviously there are other factors involved...