You should also consider going to places far off the beaten track - there are lots of towns in the USA that were reasonably populated before WWII that have lost most of their population by now. Many are in farming communities. If you go to places where you are competing with hundreds of other people with metal detectors, your finds will likely be less.
Look at joining a metal detecting club - they often work to get access to places that you would never be allowed to go to. Also, start looking at finding sites that are private (do your research to find out what areas might be of interest), and try to get access. Also, think outside the box - don't just guess where the high traffic areas are and quit looking after you find little there (you are probably not the only one who detected there), look at places where someone might have hidden things (old chicken coops, fence posts) - banks were not well trusted in the 1930's, so people tended to keep things where they knew they were safe.
Current Parks, Tot-Lots and School grounds are the first areas that people think of to metal detect at - Most have had a lot of people pick them over. Don't blame your detector, create a coin garden and hone your skills, then seek out new places.
Note: if you are in an area of high mineralization (ie. lots of hot rocks), you might need a much better metal detector.
I don't intentionally coin hunt anymore. I used to relic hunt (ie. dig everything that beeps) and dug up many trash dumps and outhouse pits at remote sites. I found my first gold ring when I was not looking for it - It was in an area abandoned around 100 years ago. It was near the outhouse pit. Obviously, there was a lot of foot traffic to that area.