You have indicated that shows on 7 and 10 digital look bad.
I assume when you refer to channels 7 and 10 digital, you mean channels 8 and 9 respectively.
Have you chosen the "UHF/VHF Antenna" "Signal Type" as indicated on the top of page 31 in your Owners' Manual? Your manual indicates that "Signal Type" does not appear in the "Channel menu" if you have set up the "GUIDE Plus+ System".
Have you set the "SAT/CABLE CHANNEL" to (S)VGA2 as indicated on the bottom of Page 42 in the RCA MM36110 Owner's Manual
Channel 8 and 9 are VHF. Channel 22 is UHF. A New York Times article described how it was necessary to carefully aim the antenna to receive 8-VSB service. The article reported that one broadcaster viewing the demonstration stated that "You have to work to find a signal" with the 8-VSB system.
I repositioned my Terk TV42 antenna with internal amplifier which is mounted on my chimney at a height of about 20 feet; and, the signal I now receive from WFOR-DT averages about 85 percent - which equates to a gain of 27 percent (85 minus 67 = 18 units) (18 divided by 67 = 27 percent gain). I'm sure that I can further improve my reception by swapping the standard coaxial cable I am using with a high quality RG-6 cable.
You may also want to try WPBT's Channel 18 sometime after 5 PM when they begin broadcasting everyday. WPBT has a strong stable signal and their transmitter is located on the same antenna farm as WFOR.
If all else fails, try another antenna.