I've resolved the problem with the link to your TV Fool report. (An extra few characters got added some how)
When you click on the path profile (click on the call sign of WSPA in your TVFR) you see that there is a tall mountain between your location and the transmitter.
http://www.tvfool.com/?option=com_wr...dALLTV%26n%3d6
Have you experimented with various mounting heights? You may find better signal higher up but with this type of terrain obstruction, you should also try lower mounting as well.