This checkoff list could be used by a scribe to keep track of which Scouts have earned which merit badges or could be used by an individual Scout.
Radio Merit Badge
Radio is a way to send information, or communications, from one place to another. Broadcasting includes both one-way radio (a person hears the information but can't reply) as well as two-way radio (where the same person can both receive and send messages).
Printable helps for requirements:
A reader asks about how old a Scout should be to work on a merit badge. The Guide to Advancement provides some answers.