We have an AU9-S antenna feeding a new HR-21 receiver. At about sixty feet we get good signal on all transponders and receive all SD and HD channels. At about 220 feet we lose all HD channels and get an error 771, “searching for signal” message. SD channels seem to be fine. DirecTV had someone here to align the antenna, and so the problem appears to be between the 60 and 220 foot runs. Again all SD channels are fine, so any suggestions on how to boost the signals to receive the HD channels? Thanks.