They don't offer locals, period- just PBS statewide.
OK, assuming your zip code is 36867, you are sitting pretty for OTA, per antennaweb.org
Since you are getting NBC well, you probably are aimed well for Fox. But you could try aiming your antenna more toward 106 degrees to see if it helps. Fox seems to be a bit behind in getting their stations up in power. Your WXTX Fox station is only broadcasting at 16 kW, although they have applied for a construction permit for a 500 kW installation. Without knowing your exact address, I can only go with the antennaweb guess that you are about 8 miles away from the antenna. So once they are at 500kW, you should be fine. Or you can put up a large rooftop antenna now, assuming you don't have one. But the best fix is for them to go full power- you might call them [(205) 298-7100] and ask when that might be. You'll need a rotor if you want more than the 4 noted networks, which are 106 to 132 from you. PBS is at 39 degrees.
The OTA signals you receive have program information in them called PSIP. Or at least, they are supposed to. Some stations do a better job than others. Dish does not pass this info on when you use the ViP622 as your ATSC (digital) tuner. If your TV has a built in tuner, you might be ahead to use that, so you can see the rather minimalist EPG that is sent OTA. Some ATSC STB DVR units capture the PSIP or TV Guide data to build up an EPG, and they can be great. How much money you wanna throw at it?
You would be ahead to stick with OTA, even if Dish ever offered you more than PBS:
1. The OTA PQ is almost certain to be better than that provided by Dish.
2. Save the $5-$6 fee Dish charges each month.
3. Dish will only provide the primary channel, not the subchannels that you can get OTA.
4. With OTA and most digital tuners, you can get PSIP data or even the TV Guide EPG.