Outside broadcast follows Frank (4,3)
I believe the answer is:
open air
'outside' is the definition.
(open air is a kind of outside)
'broadcast follows frank' is the wordplay.
'broadcast' becomes 'air' (to air on TV).
'follows' means one lot of letters go next to another.
'frank' becomes 'open' (synonyms).
'air' put after 'open' is 'OPEN-AIR'.
(Other definitions for open air that I've seen before include "kind of concert" , "definitely not in the concert hall" , "like Glastonbury gigs" , "theatre" , "concerts?" .)