On Tuesday, October 8, 2024 at 9:53:49 AM UTC-4 michael.k...@gmx.at wrote:
So: the 1,9 miles probably only work between two elevated point with a clear Fresnel zone. good point! this RF stuff is dark magic. someone should make goggles that let you see a selected spectrum or range of frequencies - kinda like night vision glasses, but where you see lights and darks (and sources and shadows) of the frequencies of interest. an example: we deployed a ubnt PtP link to connect two buildings about 600 ft apart, with thick forest between buildings. the only unforested part between buildings is a 'tunnel' about 2.5 meters in diameter, carved out of the forest for the (mostly straight) road between buildings. pointing the antenna directly at each other through this tunnel kinda worked, with a signal of around -70 db. but when we pointed each antenna toward the ground a bit, the connection signal jumped to -58 db. each antenna is only 1 meter above ground. go figure! another example: a 2 mile PtP link between island and mainland does pretty well, with antennas about 3 meters above ground on each. until a spring tide. then the signal drops completely until the water recedes. definitely looks like fresnel interference. -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to weewx-user+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/7f9c87a3-14bb-4d67-a0c0-4998c9a4178cn%40googlegroups.com.
