So why would putting that antenna outside be better than inside? 'Cuz the signal doesn't have to go through as much stuff (walls etc.) to get to the radio. Getting that antenna higher would also make a difference. It would be able to 'see' further, just like you can on top of a hill as opposed to in a valley.
There has to be a connection between that antenna and the radio for that signal to get from one to the other. The idea is to make it easier to get to that radio than going through walls etc, which introduces losses because of the walls etc. Coaxial cable is just one way of doing that. It's the pipe that makes that signal flow to the radio and still have enough signal for the radio to 'hear' it. There are 'better' pipes than others. The idea is to select the 'right' 'pipe' so that things are good, and who'z cost doesn't break the bank. That just depends on how much you want to be able to hear, and how big'a wallet you have. I don't know about you, but my wallet isn't exactly huge, you know?
- 'Doc