Radio Tower

5F: an Ultra Ball lies 4 tiles west and 5 south of the stairs down to 4F.

5F: The fake Director, a disguised Team Rocket Executive, gives you the Basement Key after you beat him, 3 tiles south of the west stairs.

5F: After you beat the Team Rocket Executive here, the real Director gives you the Clear Bell, 4 tiles east and 5 south of the east stairs.