Mike installed inside carriage for broadcast (8)
I believe the answer is:
transmit
'broadcast' is the definition.
('transmit' can be a synonym of 'broadcast')
'mike installed inside carriage' is the wordplay.
'mike' becomes 'm' (phonetic alphabet: alpha, bravo, charlie etc.).
'installed inside' is an insertion indicator.
'carriage' becomes 'transit' (I've seen this before).
'm' going within 'transit' is 'TRANSMIT'.
'for' acts as a link.
(Other definitions for transmit that I've seen before include "Pass on (a disease)" , "Send (a radio message)" , "Send - communicate" , "Send from one place to another" , "Pass or hand on" .)