In this Feb. 21, 2017 photo, lifelong ham radio operator and expert tinkerer Tom Thompson, looks at a representation of radio waves on his computer, inside his basement home office, where he operates a ham radio and other devices, in Boulder, Colo. After discovering that radio interference was being caused by high-powered lights from home marijuana growers, Thompson built an electronic filter and has given them to nearby growers. (AP Photo/Brennan Linsley)