Alright. I have also a few questions concerning dipol-antennas: first: It has often been said, that the dipol antenna, in order to receive a certain frequency, needs to have a length of λ/2. I dont see a clear reason for that. If one would not know that, one had to calculate the Capacity and Inductance of that piece of antenna (which certainly depend on the thickness of the antenna, too) And each of these quantities can only be approximated. So how does it come, that we can hit the resonance by just letting the length be λ/2? Is there a simple explanation?