Egg ad wrong. Have a go at useful small devices (8)
I believe the answer is:
gadgetry
'useful small devices' is the definition.
'gadgetry' can be an answer for 'devices' (I have seen 'ingenious devices' mean 'gadgetry' so perhaps 'devices' could also mean 'gadgetry'). I am unsure of the 'useful small' bit.
'egg ad wrong have a go' is the wordplay.
'wrong' is an anagram indicator.
'have' is a charade indicator (letters next to each other).
'a go' becomes 'try' (both can mean an attempt).
'egg'+'ad'='eggad'
'eggad' anagrammed gives 'gadge'.
'gadge'+'try'='GADGETRY'
'at' is the link.
Can you help me to learn more?
(Other definitions for gadgetry that I've seen before include "Mechanical tools" , "The making of small ingenious devices" , "gismos" , "Small ingenious devices in general" .)