Detector alternative's real deal - right? (5)
I believe the answer is:
radar
'detector' is the definition.
(I've seen this before)
'alternative's real deal right?' is the wordplay.
I cannot really understand how this works, but
'right?' could be 'ar' (I've seen this in other clues) and 'ar' is found within the answer.
The remaining letters 'rad' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for radar that I've seen before include "Aircraft detection system" , "Navigational aid" , "Remote detection device" , "Pulsed location-finder" , "Range and direction finding equipment" .)