My neighbors tree is starting to block the signal to my dish and 722 receiver. The best signal I can get is 41 on 119 and 38 on 110. 129 has some signal around 20. Until I can get the dish moved is there a way when you change the channel that it goes to sd instead of hd? I can go into the guide and select all channels to select sd but that is a pain. My neighbors that have dish are all in the seventies for signal. It did work fine until recently