I have heard since I was a child that a "fatter"antenna has greater bandwidth. But a friend building a loop out of copper tubing raises an interesting question. That loop will be fairly thick. If the distance around the loop (or think of the length of a wire antenna, or an element of a yagi, etc.) is supposed to be X, is that the distance around the outside? The inside? Up the middle? We casually use formulas, without thinking much about what the length even means!
Anything we make an antenna of,even a thin wire, will have a different length if measured down the middle, or from one edge to (at the opposite end) the opposite edge, etc. When we talk about the length of some antenna element, what matters? Of course for a thin wire antenna the difference will be small. But at a theoretical level, and in practice for larger diameters, what are we talking about? (I realize that modern tuners may make this not too important practically, but I'd still like to know!)
Bob Wilson, WA9D |
