Provide compensation for bad TV (6)
I believe the answer is:
offset
'provide compensation for' is the definition.
(to offset something is to compensate for it)
'bad tv' is the wordplay.
'bad' becomes 'off' (eg meat that's gone off is bad).
'tv' becomes 'set' (a television set).
'off'+'set'='OFFSET'
(Other definitions for offset that I've seen before include "Type of printing of efts" , "Amount by which something is out of line" , "Distance out of line" , "Compensation - printing process" , "Compensate(d) for" .)