With all this discussion about the best antenna and the trees, has anyone noticed that you have some strong local FM signals that might be causing interference to TV reception, especially for VHF-High?
This is your FM signal report, based on my estimate of your location, since I don't have your exact address:
http://www.fmfool.com/modeling/tmp/4...2/Radar-FM.png
I think you should make a test with an FM filter after the antenna. In your case, I suggest using a HLSJ instead of an ordinary FM filter.
The HLSJ can be used as an effective FM filter. It will block signals below TV channel 7, including the FM band. Use the High and common ports and insert it in the coax line from the antenna.
http://www.solidsignal.com/pview.asp?p=zhlsj
http://www.atvresearch.com/hlsjvhfba...-combiner.aspx
http://www.nsccom.com/hlsj.aspx
As I mentioned in post #2, it is important to ground the coax shield with a grounding block to reject interference which can get directly into the TV cabinet if it isn't grounded.
You also should use the Roamio Diagnostics screen to monitor signal strength, SNR, and uncorrected errors when selecting a location for your antenna and aiming the antenna.