There’s a hush when Alf turns up with the news (5)
I believe the answer is:
flash
'the news' is the definition.
(flash is a kind of news)
'there's a hush when alf turns up' is the wordplay.
'there's a hush when' becomes 'hs' (I can't explain this - if you can you should believe this answer much more).
'turns up' says the letters should be written backwards.
'hs'+'alf'='hsalf'
'hsalf' written backwards gives 'FLASH'.
'with' is the link.
Can you help me to learn more?
(Other definitions for flash that I've seen before include "sort of flooding" , "emblem on uniform" , "Shine briefly; showy" , "Short gleam of light" , "Twinkling" .)