ORIGINAL: bbbair
No; the antenna does not have to exit the airplane in order to work.
What you need to do is ensure is that the antenna is fully extended (no major bends or kinks). We have seen people that wanted that "Clean Look" and they actually COILED up the antenna in order to make it fit inside of the AC.
This has the effect of shortening your antenna and 'REDUCING' your range. - you could loose your AC if you let it get too far away. [
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The average antenna is 39" long, if you can keep that much antenna inside of your AC (in a strait line) - it will probably work just fine.
Au contraire, the antenna MAY be coiled up inside the fuse and still provide more than adequate range for our purposes. You just have to make sure that it is coiled CORRECTLY.