Shine in Ulster broadcast (6)
I believe the answer is:
lustre
'shine' is the definition.
(lustre is a kind of shine)
'ulster broadcast' is the wordplay.
'broadcast' is an anagram indicator.
'ulster' with letters rearranged gives 'LUSTRE'.
'in' is the link.
(Other definitions for lustre that I've seen before include "Brilliant quality in a material, porcelain, etc" , "Gloss, sheen" , "Gentle sheen, soft glow" , "Radiance; reflective surface" , "Distinction < in five years" .)