We did this years ago - one of the best budget moves we've made - especially since we watch very little tv! Bought a wireless antenna from
Amazon (about $30). It is about the size of a legal-sized piece of paper (11x14-ish) and is pretty much just a wire grid. We put it on the floor of our attic crawl space and get all of our local stations just fine. You sort of point it towards the general area where the signal comes from - might have to spin it around a bit to get the right placement. You have to follow the directions with your tv set(s) to set that/them up for "antenna" rather than "cable" but that took about 30 seconds for us (one tv). Our only issue is that when it gets VERY windy, sometimes some of the stations/shows might cut out for a second or two. Doesn't bug us since it happens so rarely.
Good luck to him!
ETA: I don't know anything about HOA restrictions (don't have them here), but our antenna is inside our house, so wouldn't be an issue anyway. Maybe one of those honkin' big/tall ones mounted to a roof would be. Also, there is a LOT of info online for antenna hook ups - he can just do a Google search and find what he needs, too.