Hello and thanks in advance. I got Dish installed today but the tech told me I am only able to get SD channels because of some tree tops. Well at the moment I am able to get at least 10 HD channels but some of the main ones I really want (Tennis, Comedy Central, ABC, NBC, CBS, TBS, etc) are not coming in HD, only SD. Why is that? Are they on a different satellite? If the top of the trees go away (winter is coming, or they meet an untimely demise) will that help and if so, would the tech have to come back out for a service?