I define radio quality as a good sounding song placed behind compressors and eqs to make it sound more marketable to the masses. The more enjoyable, the better the chance that the listener will buy the CD, keep the station playing in his car,
and patron the advertisers that basically pay for the station.
The masses currently like music that is totally in your face with no dynamics. They hate volume swells and believe that acoustic passages should be just as loud as electric passages. The masses do not particularly care for good song writing, and every ten years, the masses will open up a small window of opportunity to let fresh, creative talent in the house. At any other time, the music has to blend nicely in the background because it makes for the soundtrack to their pathetic lives.
However, when someone in a recording forum such as this refers to "radio quality", I step outside the literal term and assume they mean "professional CD quality", which I believe can be done at home, but will take large amounts of energy, patience, preserverance, humility, trial and error, and knowledge, as well as a visit to a mastering engineer near you.
Cy