I've got a DISH6000/OTA module being fed from a CM4248 UHF Yagi with rotor and preamp. After recently raising the antenna a few feet higher, I am suddenly experiencing spikes/drops and dead periods that are rendering my local digital channels unwatchable. For example, I'll have a signal strength of 72%, which will spike to 81%, then drop to 58%, and then go dead at 00%, all within a few seconds time. Then the channel may hold steady for 10-15 minutes, before repeating the cycle and losing the picture again. This is happening on all of my major local digital channels, but at different times. Is this just a "bad air" week for me, or is something wrong with my equipment setup?