in a 5.8MHz antenna the signal weakens a lot when passing through trees but on rainy days the signal almost does not pass, my question is why the signal gets much worse when it rains than when it is sunny, on the sunny day I have a signal - 68 and on the rainy day the signal is always changing up and down, what is the role of the water in the radio signal and why the signal is so, of course I imagine that in the tree must accomodate much water mainly in the leaves . I have a router sxt lite5 ac on one side and the other side an identica but being a cq, Can I study more about signal and frequency if I suggest something?
You have to be in line of sight with the tower, so a -68 signal with trees in the middle would really drop even with wind.
Avoid trees and get a better signal and rain wouldn’t disconnect stations.
Non-distilled water is conductible … only slightly, but still. Any conductor affects EM waves and so does water. Either on radome (neglectable) or parabola grille (almost neglectable at 5GHz) or tree leaves. On a sunny day, contents of water in tree leaves is smaller, hence medium effect on radio waves. On a rainy day, with fluid water depositing on tree leaves, the effect is much bigger. The same effect gives icing while snow has smaller effect (watter content is smaller and actually individual ice crystals affect the radio waves and those are too small to have any effect other than slight dampening). The biggest effect of thin watter layer is (partial) reflection. As tree leaves gave random directions, the net effect is scattering of radio signal.
The worst effect on radio link of all watter forms is the one by hail. It can cause permanent damage to the link 