4 was good... but 9 was better... I remember some kid who came in with a 17 transistor radio!
Pity the poor kid who had only a 1 transistor radio.
I remember listening to the World Series with an earphone (what they call an "earbud" these days) connected to a red rocket shaped crystal radio that had a wire with an alligator clip that you attached to a ground... a true no-transistor radio.