When you refer to 7.1, I presume you mean WMKE-CA. There is some doubt as to whether it's currently on the air.
http://en.wikipedia.org/wiki/WMKE-CA would have me believe it's still broadcasting an analog signal on real CH-7 and that the construction permit for a digital facility on real CH-21 has yet to be built.
I presume 36.1 refers to WMVT, a PBS affiliate. The single best improvement available to most folks in your situation is often 'move the antenna out of the attic'.