An outside antenna will greatly increase reception. Rules of thumb are: go as high as you can and use the best coax you can afford (lowest line loss). Also try to cover/coat your outside connections so as to reduce moisture ingress which leads to premature corrosion.
Lastly form a "drip loop" at the end of the cable nearest the antenna. If you do have to replace a connector due to corrosion (which will happen eventually), you'll still have enough cable to do so.
Here in southern Jefferson County, I'm able to pick up Hardin County (2 counties away) with an outside antenna. However, going east is more challenging - Oldham and Shelby are "iffy", but I think their towers are as far away from me but still being in the county.
Lastly form a "drip loop" at the end of the cable nearest the antenna. If you do have to replace a connector due to corrosion (which will happen eventually), you'll still have enough cable to do so.
Here in southern Jefferson County, I'm able to pick up Hardin County (2 counties away) with an outside antenna. However, going east is more challenging - Oldham and Shelby are "iffy", but I think their towers are as far away from me but still being in the county.