We have a terrestrial microwave link at work we use for live shows. The receiver is nothing more than a standard 18" off set dish just like Dish's and DirecTV's.
There were two places where the tech had all sorts of issues getting signal from the transmitter. Both were because the transmitter was below the receiving dish. Well the tech (generally a smart guy) kept pointing the dish directly at the transmitter without taking into account the off-set. When I suggested he mount the dish on the pole up-side-down to get the signal, he thought I was looney-toons! It took me, three pages on the internet and a hand drawn diagram from me for this generally intelligent, articulate technitian to even think about doint this. Still, it took until I personally mounted the dish "up-side-down" on the pole and aimed it myself for him to realize how much stronger the signal came in!

He still doesn't understand the whole "off-set" idea. But the dish is always mounted up-side-down now.
See ya
Tony