I am always on the lookout for "things that make you go hmmmm" in the Ham Radio world, that raise serious questions to the point of disproving the earth being a globe. This isn't a slam dunk like various experiments I've seen done by various Flat Earthers over the years, but it's some level of evidence. This isn't a "proof" the way the nαzι VHF radar was a proof. But it adds to the body of evidence, so here you go.
If you have your eyes and ears open, you run across this stuff all the time. Invariably, the people shrug it off as one of those things, one of life's mysteries, one of those phenomena that still baffles science -- but they never "go there". It's like they know where that path leads. They always cut the thought short before they commit a mental sin of heresy. George Orwell discussed this process in his famous book 1984, he called it "Crimestop".
Disclaimer: Josh Nass (Ham Radio Crash Course) is NOT a Flat Earther and certainly does not endorse what I'm doing with his video.
I wish I had started this collection 6 years ago, but alas I did not. Nevertheless, when I'm listening to a podcast or watching a video now, and they say something that isn't getting enough attention, I save it off. I cut it into a separate clip and set it aside.
VHF radio does not bounce off the "ionosphere", even according to mainstream science. VHF is line of sight. And remember, if 100% of a signal went into space (which should absolutely happen if the earth were curved), no amount of amplification could bring it back. Just like with telescopes and visible light (images). If something is HIDDEN behind "earth bulge", then no telescope in the world would be able to bring it back into view.
A billion times 0 is still 0!