Is there a minimum voltage output required to operate a hopper? The reason I ask is that a Dish tech told me to expect problems if the voltage drops below 118 volts. My voltage typically runs 116 to 118 volts. He said they have fewer problems at houses that are running between 118 and 123 volts. He said he would expect that I should have problems with my current set up (two 722 and two 222 receivers), but I rarely have any issues with my current receivers. He did say using a UPS battery backup might take care of any problems. Thanks for any information.