We have had DISH for almost a year. We have a Sony 36" HDTV. Mid January we bought a Terk OTA HD antenna. We hooked it up to our DISH 811 receiver. Doing a digital scan, with the antenna pointed in the right direction, we immediately picked up the local HD channels. Superbowl was awesome and March madness started out great in HD. Then, two weeks ago, we totally lost local HD channels. DISH service suggested an amplifier from Radio Shack since (they said) signal strength is compromised at change of seasons. Bought that, no good. Bought a new antenna, still doesn't work. We have reset our box and spent hours on the phone with DISH. Any ideas???