I was upgrading the "MATV" (master antenna TV) network at my mom's. Replacing the RG59 with RG6 for less attenuation. But I was getting erratic reception on some local NYC stations. I went to tvfool.com to find out where the signals of interest would be coming from. So I got the angle from true north, but the house is not orientated directly north-south, but at an angle. So I got a google map to get that angle (house is parallel with the street).
Once I got the above angles, I could point the antenna more accurately (I was off by about 15 degrees). The diagram shows my analysis.
This solved the erratic reception.
This is that antenna, VHF but I gets enough UHF to work those channels as well.