I fill my deer tags every year,but hunting coyotes isn't as easy they are coming in cautious and looking for the sound,they can pick you out of cover that a deer would never see you,and there nose is very good,it can smell just a hint of human odor and you never know they are there.It sounds like you did everything right,sometimes they just aint willing to play and commit themselves to coming in.Just keep on calling and a dying rabbit sound will kill more coyotes that any other sound.Good Luck!!