Need advise, I currently have a 522 and Dish 500 with DPP LNB. I use this system at home and also move it to my RV when I travel. I use a second Dish 500 DP twin LNB on tripod. I usually am able to aim this dish with little trouble unless we are in a wooded area. My question is about upgrading to HD. Most of the posts indicate the need for an additional dish to aim at the HD satellite. Is this really necessary? Are there systems that receive all the satellites on one dish? How hard is it to aim for HD? What costs should I expect?