Create A Sql Loop Using Alphabet Characters

I have a basic while loop but I need to be able to increment the counter from one alpha character to the next:

declare @counter nvarchar(10)

set @counter = 'A'

while @counter < 'Z'

beginprint 'the counter is ' + @counter

set @counter = @counter + @counter

end

 

In this example I would need to see the following output:

the counter is A
the counter is B
the counter is C
the counter is D
.....

Is this possible in SQL?