My radar is fixed to part of the mast (7)
I believe the answer is:
yardarm
'mast' is the definition.
(I've seen this before)
'my radar is fixed to part of' is the wordplay.
'is fixed to' says to put letters next to each other.
'part of' indicates an anagram (I've seen 'parts' mean this (the parts of the original word ordered differently)).
'my' put after 'radar' is 'radarmy'.
'radarmy' is an anagram of 'YARDARM'.
'the' is the link.
(Other definitions for yardarm that I've seen before include "Part of a ship's rigging" , "End of a beam supporting a sail on the mast of a square-rigger" , "part of ship" , "place of naval execution" , "Tapered point of nautical spar" .)