Thank you all, and both elle and therougue for your input on this one.
The only other way to solve it, is if we swap the "Y" for the "D", making the word, as you said " FIELD" in the answer for "corn field station.".
And the letter " D " in "Radio"
Third shaded box in the clue.
We are lucky with this, as Andy Warhol has only one letter "D"
CLOCK R A D I O STATION "3rd shaded box "
This then would be CLOCK _ _ Y _ _ STATION
Hope this makes sense.