14 is plenty old enough to easily get into Ham radio, which opens lots of doors, and will teach him a lot. If you check out myGMRS.com and there's a repeater in your area listed as being "open" that might also be an avenue to look into, the license is more $$ and you can do less with it, but it's easier to start with. New repeater capable radios can be found for a little over $100 used gear for a little less.
I'd recommend having him look at the W5YI HAM Technician book (It's a little less intimidating than the ARRL version) and if it's enough to get him hooked just let him keep learning it'll make the high school and college physics classes easier on top of fueling that interest/hobby.
Basic scanners are also a good place to start with the interest and listening, and as he hears what's out there (Air, Police, Fire, Business, HAM, GMRS, CB [some is good, some is immature, almost all is road travel centric], weather radio, etc) He can listen and decide what interests him, what's active and what direction he wants to go.