Consider this...since it is late in the season it is obvious that most hens are on the nest and the fact that the one you are dealing with is not on the nest could mean she is a Jenny (Jake equivalent). This means she is going to shy from older sounding adult hens if they are off the nest they will be territorial. In calling raspy, as we all tend to do imitating older receptive hens. The Tom you are calling is likely had his tail fan ruffled by another gobbler too by this time.
Try a single hen decoy set-up and then Kee-Kee to him/them and maybe a few clucks. What you are telling them is that one - you are alone, two - you are young and not a threat, three - appealing to their social nature and not the breeding nature to threaten the young hen. He will respond to either as he has interests in both.
Might sound like a bit of an involved explanation, but I have done this for years and could fill a truck with birds killed this way. If you try this let us know if it works.
Good hunting!