Shortwave operator (3)
I believe the answer is:
ham
'shortwave operator' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ham that I've seen before include "Overacting actor" , "Meat of the hog" , "Tasty meat for thespian who overacts" , "Meat for actor who overdoes it" , "Gammon" .)