The first thing to know is that you want the outside antenna located in the best signal area (see the tools in the top paragraph) available while providing the best separation between the inside and outside antennas

no more dropped calls sitting in a aluminum motor coach in a weak cell phone area that we stay for months at.

I headed out on a trip to the property and drove for 75 miles passing through towns with strong signals and areas in the hills with weak signals

Yes, some areas are stronger than others, but I have coverage!.

Found the Strongest signal area outside to place antennae and increased signal almost double