During my years in broadcasting I had the opportunity to work in radio from time to time. I earned my radio license and worked as a part-time radio announcer. That license required me to pass a written exam that include several mathematical concepts regarding radio wave propagation and signal processing. Back then to be an announcer you had to possess a valid 3rd Class licence with Broadcast Endorsement. The following programs are examples of some of the things one had to know how to do back then.