It first appears when Maxwell makes first contact with Wilson in the Forbidden Knowledge video, used as both a means of verbal communication and a way to channel information into Wilson's brain.
The radio makes a second appearance in the wilderness, as it makes up the primary component of the Divining Rod. This time, it broadcasts a sound (as well as a visual cue) that increases in intensity the closer the player approaches to a Thing, Wooden Thing, or Maxwell's Door. As a part of the Divining Rod, it is required to activate the Wooden Thing in order to move from world to world in Adventure Mode, and it ultimately acts as the key to Maxwell's release from the Nightmare Throne.
As stated by a developer:
"The radio is a Voxola PR-76, manufactured in 1919 by the Voxola Radio company of Sidney, Ohio. The radio offered revolutionary sound and reception quality for the time, and was promoted by an intense national marketing campaign. Very few units were actually produced, because the factory was destroyed in a fire only days after production began. Voxola founder Robert Wagstaff went missing the night of the fire, and the company declared bankruptcy soon thereafter."
- It is possible that Wagstaff made a deal similar to Wilson for "Forbidden Knowledge" in order to produce the advanced radio. The marketing campaign may have also been influenced by Maxwell through Wagstaff in order to distribute the radios as widely as possible. Since the radio is demonstrated as Maxwell's primary means of interaction with Wilson, it can be inferred that his plan was to distribute the radios as widely as possible to provide him with a greater pool of potential "playthings". Since the fire shut down mass production, it is highly likely that each of the characters appearing in Don't Starve received a radio from that limited run.
- The plot in this piece of speculation has similarities to the Doctor Who episode, The Idiot's Lantern.
- It can be inferred that Wagstaff was abducted by Maxwell on the night of the fire. All Don't Starve characters, short of Maxwell himself (and this may be debated due to the previous existence of William) possess a first or last name beginning with W.