[hvalentim]

in the last two days I measured the antenna gain in the band of 433MHz. The results are quite interesting and maybe answer a range of questions:

Wonderful work. Thanks for sharing.

I have been using the 20 cm model on the TX side and a 13 cm model on the RX side (both placed vertically).

Works well enough for me (~7 meters apart, TX on roof, RX close to a window just below).

But I am now convinced it is perhaps not the best possible combination.