How to make a television antenna

I haven't explained much, I was rather responding to Skull :)
As for the link, it explains how to build an antenna, focusing more on the practical side. To calculate the length of each element, you need to apply the formulas given in one of the two drawings. So this should be done before buying the materials!!
F: it's the frequency of the channels to be received (in MHz = megahertz). Each channel has its own frequency, so you need to check locally. If you need to receive several channels, which is generally the case, you calculate based on the average of those frequencies.
λ: is the wavelength of the frequency to be received ( https://fr.wikipedia.org/wiki/Longueur_d%27onde ) scroll down to "Électromagnetic wave". But you can do without it since you can use F.

It's not complicated, just a few X or:
Preferably make the one with 5 elements because its gain will be higher.
Good luck with your build.