Fixed the telly? (3)
I believe the answer is:
set
I believe this clue is a double definition.
'fixed' is the first definition.
(both can mean decided or determined)
'telly?' is the second definition.
(telly is a kind of set)
'the' acts as a link.
(Other definitions for set that I've seen before include "Create a puzzle" , "Prescribed" , "Go below the horizon," , "conventional" , "Become stiff like jelly" .)