When I used the dimension tool for diameter, the symbol showed at the beginning (left). Our desired format shows as 25"∅. To get this I added a space to the prefix field to suppress the ∅ at the beginning and added the "∅ symbols to the suffix field (right) and set the "offset from dim line" under  the Text tab to 0 so there isn't a large gap shown. Is this the only way to do this? I figured I would post this so anyone else wanting to adjust the appearance could find this. It took me some testing to get it to show like this also as our normal dimensions show with ticks and not arrows as we want for diameters.