The phrase "radio dial" refers to the round or digital panel on a radio that you use to select different stations by turning or pressing buttons. Full definition
Every show is available to you via podcast, on your local radio dial, or via online streaming. (lifestylesunlimited.com)
For those stuck in traffic, tune in to the Los Santos radio dial for a wide range of music styles to choose from - check out radio station previews of Radio Los Santos and Channel X plus Rebel Radio, East Los FM, West Coast Classics, Fly Lo FM and Vinewood Boulevard Radio. (rockstarwatch.net)
When I found something to choose, I would press the nondescript radio dial button on the right of the LCD, look above to see what the E Ink screen now had on it, and then look below to see what additional navigation choices were available. (macworld.com)