Does anyone make a dvd that is good on how to use a diaphragm call? I have played around with them and can make some cow mews but want to improve on my calling. I have heard on other posts a call maker helping Dana with his calling and posted some great info. I have bad internet in my neck of the woods so youtube or other internet videos are not going to work. I am looking for a descriptive how to like where to place the call your tounge and what words to say as you call. Please help me be a better caller. Thanks.......