Outstanding work in radio post, extremely eager, calm, we hear (11)
I believe the answer is:
masterpiece
'outstanding work' is the definition.
(I've seen this before)
'radio post extremely eager calm we hear' is the wordplay.
'radio post' becomes 'mast' (radio mast).
'extremely' says to hollow out the word (remove centre letters) (only the extremes of the word are used).
'calm' becomes 'peace' (peaceful situation).
'we hear' shows a homophone (sound like).
'eager' with its middle removed is 'er'.
'peace' sounds like 'piece'.
'mast'+'er'+'piece'='MASTERPIECE'
'in' acts as a link.
(Other definitions for masterpiece that I've seen before include "outstanding achievement" , "Chef d'oeuvre" , "Superb work of art" , "Work of extreme skill" , "major artwork" .)