Hi Grady43,
Your reception plot isn't very favorable. The majority of signals on the list are gray and in negative db signal strengths. Generally, negative db signal strengths require great luck or extreme measures to receive. I have personally never decoded a gray shaded signal.
That said, you need an aggressive set up out of the gate. Tri-Cities' NBC and CBS are going to be your most likely shots at reception. Further, your situation requires a low-VHF capable antenna (channels 2-6) and one that supports high-VHF (channels 7-13). UHF is likely out of your reach.
I suggest an
Antennacraft HD1850 http://www.solidsignal.com/pview.asp...a-%28hd1850%29. This antenna is recommended because of the gain provided and its coverage for real channels 2 - 13.
I see your plot is at the block level. I would try to rerun it at at your address level. Then look to see if additional heights of 50' and 75' make any difference.
Installing, you will want to mount the antenna above your roof towards magnetic 350 with the clearest pathway possible free obstructions. Suggest also testing a couple locations if NBC and CBS are unreliable. Sometimes moving antenna a few feet results in a difference between drop outs and stability. If I were installing this set up I might purchase a
RCA TVPRAMP1R preamplifier.
http://www.solidsignal.com/pview.asp...u=044476071669.
Regarding reception of WBIR Knoxville, from Roan Mountain that reports to be 130 miles. If at a high location, reception may be better than TV fool reports. You'll just have get something in the air and see. I reran a TV fool plot at 500' at the city level of Roan Mountain. Knoxville is at magnetic 270. I recommend testing various markets like Tri-Cities, Asheville, Kingsport in addition to the already mentioned Knoxville.
Looking at your plot and not knowing anything about your location. I'd expect to see NBC and CBS from Tri-Cities with the most ease. Anything past that with your 2-edge conditions, you'll be into wildcard territory.
Best of luck.
