161,
Any time you 'add' an element to a single element antenna such as a dipole/yagi, the input impedance goes down some. So a 1:1 balun isn't going to result in a 'perfect' match. Neither will a direct connection. Won't be a particularly 'bad' impedance match, but not a 'good' one either, normally. A balun's transformation ratio is a 'ball-park' sort of thing, and 'close' does count, as long as that 'close' is reasonable (and in the right direction).
A balun's primary purpose is to transition between an unbalanced feed line and a balanced antenna. At HF, that transition isn't really too necessary especially with beams. The symetricity(sp?) of the radiation pattern is the main result. Without the balun the pattern will be slightly 'skewed', but in most cases, you'll never know it. Already have the balun? Use it. Don't have one? Don't worry about it. Or try it later, see what happens.
- 'Doc
Any time you 'add' an element to a single element antenna such as a dipole/yagi, the input impedance goes down some. So a 1:1 balun isn't going to result in a 'perfect' match. Neither will a direct connection. Won't be a particularly 'bad' impedance match, but not a 'good' one either, normally. A balun's transformation ratio is a 'ball-park' sort of thing, and 'close' does count, as long as that 'close' is reasonable (and in the right direction).
A balun's primary purpose is to transition between an unbalanced feed line and a balanced antenna. At HF, that transition isn't really too necessary especially with beams. The symetricity(sp?) of the radiation pattern is the main result. Without the balun the pattern will be slightly 'skewed', but in most cases, you'll never know it. Already have the balun? Use it. Don't have one? Don't worry about it. Or try it later, see what happens.
- 'Doc
