Ace, how far do you live from the transmitters, are they all in the same general direction, and is the terrain flat between you and them?
I have a BIG antenna pointed at San Diego, 60 miles away. I can get half of the channels all of the time, and the other half most of the time, except when it rains or is foggy. The bad thing about digital is that the signal strength is either adequate or it's not ... there are no snowy analog pictures; it's either receivable or not.
This is necessary because we're just barely in the LA market area, so cable and Fios give us LA channels. But DW is a big Chargers fan.