A higher antenna height will most likely help reception.
Directional antennas receive the best at the front of the antenna and then to lesser degree at front angles to the antenna and then back angles to the antenna and then the back of the antenna.
Directional antennas receive the least amount of signal directly on the sides of the antenna.
Adjust the HD7694P antenna so the channel 49 transmitter at 56 degree magnetic compass direction is more at a back angle to the antenna.
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Digital Broadcast Tv tuners can develop -Digital Glitches- that are not cleared out with simple channel scans.
Do Double Rescan ,
http://www.wchstv.com/DoubleReScanAlert.pdf.