Scottish town's broadcast on the radio (3)
I believe the answer is:
ayr
'scottish town's' is the definition.
(town in Scotland)
'broadcast on the radio' is the wordplay.
'broadcast' becomes 'air' (to air on TV).
'on the radio' indicates a 'sounds like' (homophone) clue.
'air' is a homophone of 'AYR'.
(Other definitions for ayr that I've seen before include "Scottish salmon river" , "Scots. town; sounds like song" , "Scots port on Firth of Clyde" , "Scottish seaport" , "Scottish town, port and racecourse" .)