Again fixed the engineers' radio (5)
I believe the answer is:
reset
'engineers' radio' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'again fixed' is the wordplay.
'again' becomes 're' (prefix meaning 'again').
'fixed' becomes 'set' (both can mean decided or determined).
're'+'set'='RESET'
'the' is the link.
Can you help me to learn more?
(Other definitions for reset that I've seen before include "Return to original configuration" , "Put together again" , "Restore to original state" , "Trees (anag)" , "Steer so as to fix broken bone" .)