A small, local talk back radio station associated with Vault-Tec University, on the edge of the Cranberry Bog and the Mire, KMAX's programming was of the crackpot variety, reaching Mothman believers across Appalachia.
The hole in the wall that is seen next to the KMAX logo when fast traveling to this location actually leads to the back of the building. This fenced-in area holds the actual radio tower and a weapons workbench. Also out back is a trailer with some minor loot inside. However, if one jumps onto the nearby barrel, then onto the wooden planks, and then onto the concrete wall, they can access the top of the trailer, on which the broadcast station key sits next to a cooler.
This key unlocks the blue door found by circling around to the other end of the building. Upon entering, there are two shelves blocking another door; below them is a locked floor safe. To the right is the broadcast room, filled with junk items and a terminal.
KMAX Transmission appears only in Fallout 76.