Tv signals are funny things. Antenna location A few feet N,S,E or W can have a signal be 95% or 15%.
So that ideal location you have in mind for the location in your attic, a few feet to either side if it might increase reception 3 fold on some channels and reduce it on others.
Some LED lights affect Tv reception
Run some autoscans for channels, trial and error style before devoting a location for the antenna.
TV fool.com will tell you if you still have channels in the VHF hi band. If there are channels still being broadcast on 7 to 13 actual in your area, these require longer antenna elements than UHF channels.
Finding the strongest signal location for your favorite channel might be a PITA that compromises other channels.