Volume of band on radio unacceptable - about eleven in the end (6)
I believe the answer is:
amount
'volume' is the definition.
(I've seen this in another clue)
'band on radio unacceptable about eleven in the end' is the wordplay.
'band on radio' becomes 'am' (I can't justify this - if you can you should believe this answer much more).
'unacceptable' becomes 'out' (out can mean incorrect or inappropriate).
'about' means one lot of letters goes inside another.
'in the end' indicates one should take the final letters.
The last letter of 'eleven' is 'n'.
'out' enclosing 'n' is 'ount'.
'am'+'ount'='AMOUNT'
'of' acts as a link.
Can you help me to learn more?
(Other definitions for amount that I've seen before include "value" , "Quantity, sum" , "Measure, quantity" , "A quantity or total of anything" , "Size" .)