Yagi-Uda antenna calculator
Wavelength (λ): N m = N*100 cm
| Lengths | |
|---|---|
| Reflector (0.50λ) | N cm |
| Driven element (0.44λ) | N cm |
| ½ driven (0.22λ) | N cm |
| Directors (0.43λ) | N cm |
| Reflector-driven (0.25λ) | N cm |
| Driven-director & director-director (0.13λ) | N cm |
| Approx. total wire length | N cm |
| Approx. total boom length | N cm |
Note
The "boom" is the part that holds all the elements, purple on the diagram.
The driven element is the part that you connect to your hardware, just like a dipole.
Also, I've heard somewhere that you should connect it through a balun or something - not sure though, and if you do know for sure, contact me or contribute.
Generally the gain increases as you add more directors, see here.
There are way better designs than this one. For example, this one for the 70cm band (~432MHz), carefully tuned by someone who has a clue as to what they're actually doing and with lots of directors for lots of gain.