I agree with txjourneyman...call sparingly...maybe in 15 minute intervals to start out. If you get a gobble right after one of your yelps, wait a while...the gobbler has recognized you and may start to make his way over. There is a lot of trial and error involved in turkey hunting...especially if you are out in the field by yourself. If you know someone who really knows what they are doing, then I would try to hook up with them on a couple of hunts and just observe and ask as many questions as you can.

Sounds like you know where the birds are. If you can find out where they are coming from and going to, then you have half of the battle won! Once you know where they are coming from and going to, just set up between the two and call every so often. I think if you do this, you should have some pretty good results. Best of luck!