Install the CM4228HD antenna above the roof in such a manner that the roof and house are not impeding and blocking reception in the directions of , North West , North , North East , West , South West , South East.
Aim the antenna at about 342 degree magnetic compass direction.
Here is how to aim antennas ,
http://www.kyes.com/antenna/pointing/pointing.html
Use a Old School magnetic compass to aim antenna.
A Winegard DS3000 J pole type antenna mount works Ok with the CM4228HD antenna.
Digital Tv tuners can develop - Digital Glitches - that are not cleared out with simple channel scans.
Do Double Rescan ,
http://www.wchstv.com/DoubleReScanAlert.pdf.