Channel in same broadcast feature (5,6)
I believe the answer is:
'channel' is the definition.
(I know that Menai Strait is a strait)
'in same broadcast feature' is the wordplay.
'broadcast' indicates anagramming the letters (letters scattered or cast around).
'feature' becomes 'trait' (I've seen this in another clue).
'insame' with letters rearranged gives 'menais'.
(Another definition for menai strait that I've seen is " Welsh channel".)