Depressed broadcasting centres about to collapse (11)
I believe the answer is:
crestfallen
'depressed' is the definition.
(I know that crestfallen is a more specific form of the attribute depressed)
'broadcasting centres about to collapse' is the wordplay.
'broadcasting' is an anagram indicator.
'about' is an insertion indicator.
'to collapse' becomes 'fall' (I've seen this in another clue).
'centres' anagrammed gives 'cresten'.
'cresten' enclosing 'fall' is 'CRESTFALLEN'.
(Other definitions for crestfallen that I've seen before include "Dejected after blow to pride" , "Sad, disappointed" , "Low" , "Feeling a blow to one's pride" , "Downcast" .)