Old Microwave Sites that were part of the AT&T Microwave Radio Relay System. Most are SBNO. Some are dismantled. This map includes TD-2 (4 GHz) and TH (6 GHz) sites.I saw a bunch of old Microwave Horns on top of the AT&T Building in downtown Oakland, CA and wondered if they were still in use. Because I'm an old technology geek, it started me on a research and mapping project that's "just for fun."Site Legend: Green: All horns present. Yellow: One or more horns removed. Red: All horns removed. Full Dot: Tower and/or site demolished.Path Legend: Green: Path good if radios were present. Red: Path dead due to removal of horns or tower.