He should contact his Radio Merit Badge counselor for information. There are many Amateur (Ham) radio operators in the Tri-Community area. If you are still having trouble with that requirement, he should contact the California Inland Empire Council in Redlands for a list of MB counselors.
The requirements state:
7. Visit a radio installation (an amateur radio station, broadcast station, or public communications center, for example) approved in advance by your counselor. Discuss what types of equipment you saw in use, how it was used, what types of licenses are required to operate and maintain the equipment, and the purpose of the station.
While I am a licenced Amateur radio operator, and I may still be on the list as a BSA Radio MB counselor, my radios are all portable units called Handi-Talkies or HTs. In my mind, looking at my radios would not qualify for this requirement, since they are few in number and I don't have an external antenna. In order to appreciate the world of Amateur radio, he really should look at a larger station, and if the camp counselor is good, he can discuss with your son how all amateur operators started out with small stations or HTs, and grew their hobby from that point.
Good luck!
Matt/N4MAN