I've been fighting this issue for years. My OTA locals are prone to pixelation because of my location. I'm close enough to the transmitter towers but there are several hills in my way. Some days are worse than others and I can find no rhyme or reason - sunny day, cloudy day, rainy day? I often get better reception after the sun goes down. I've tried several different rooftop antennas with no improvement. I have three different ways to watch OTA locals - one is through the tuner in my ViP211k Dish receiver, then there's the tuner in my TV and I also have a ADTH TV Box that performs the best of all three. It also tunes the new ATSC 3.0 NextGen channels. The Dish receiver freaks out and displays "739 Error" screen while it tries to figure out what to do. The tuner in the TV and the ADTH Box handle the interruptions (pixelation) much better and a lot quicker. Airplanes flying between me and the transmitter, a car going past my house and anything else that might cause a reflected signal to arrive at the antenna will cause a dropout. Other times the dropouts must be weather related. Of the three tuners, the ADTH TV Box handles the dropouts the quickest and returns the picture much faster than the Dish receiver and a little faster than the built-in TV tuner. I've got the Dish receiver and the ADTH TV Box connected with HDMI cables. The TV is a Westinghouse "smart" TV so that every time I turn it on, I have to select the input which makes switching between tuners as easy as pressing a button on the remote.
