I know some people have told me in crazy, but I try to use what my grandmother taught me. Broom straw. Get a piece of broom straw that is as straight and possible and find a pet well rounded spot on your melon, lay the piece of straw on that spot and gently let it go. If your melon is ripe the straw will actually spin, it may not spin like a helicopter blade but it will turn on its own. I have only ever tried this in the grocery store to check melon's for ripeness but I'm sure it will work in the garden and well.
I know some people have told me in crazy, but I try to use what my grandmother taught me. Broom straw. Get a piece of broom straw that is as straight and possible and find a pet well rounded spot on your melon, lay the piece of straw on that spot and gently let it go. If your melon is ripe the straw will actually spin, it may not spin like a helicopter blade but it will turn on its own. I have only ever tried this in the grocery store to check melon's for ripeness but I'm sure it will work in the garden and well.