TV antennas don't work like satellite dishes do: you need a high point in order for the antenna to see the transmitters. in your case, all of the transmitters are on South Mountain about 28 miles from your house. attic installations are hit-ot-miss: mostly miss. if oyu want reliable reception, you really need to have a TV antenna outdoors that can see over the highest point of your roof. Most Phoenix-area houses use clay or concrete-tile roofs, which severely block TV signals to an attic-mounted antenna. Additionally, attics have HVAC ducting, sometimes have foil-backed insulation, and other obstructions that mess with TV reception. My suggestion would be to buy a Winegard HD-7694P VHF-high-band VHF plus UHF atenna, mount it on your roof or on a wall where it can see above the roof, and aim the front of the antenna at 150 degrees by your compass.
Remember that your local HOA cannot prevent you from installing a TV antenna on your property to receive local TV channels: the FCC made that ruling 15 years ago, and it has been upheld in courts all over the counrty, so don't be afraid to install the antenna outdoors where it can do the most good.
http://www.fcc.gov/mb/facts/otard.htmlHere is the suggested antenna:
http://www.winegard.com/kbase/upload/HD7694P.pdfand here is a good antenna installation manual:
http://www.winegard.com/kbase/upload/1450290.pdfhttp://manuals.solidsignal.com/AntInstallGuide.pdf