Tricky. It depends on the context. "Radio" can mean an object, a radio receiver. The plural is spelled without an "e," "radios." Pocket-sized transistor radios first became available in the 1950s (and I remember them well). It is hard to believe that cheap plastic radios have become collectors' items. I wanted a plain radio, but all the radios in the store were clock radios with iPod slots. "Radio" can also refer to the technical system of sending and receiving radio waves. That would always be singular. There are two kinds of radio, AM and FM. Is there anything good on satellite radio? Once you get away from the big cities, it's hard to find any classical radio. I don't like to listen to talk radio, everyone sounds angry.

radios. i think that it is countable noun. radio means listen device radio.