There are a total of eight radio sets scattered across The Giant map that contain audio messages from different characters in the game. Five of the radio sets contain messages from Maxis and three from the other characters except for Richtofen.
Note that these radios relay 11 different messages, three of which can only be accessed if you are playing as Richtofen. These messages bridge the gap between the story of Black Ops 2 Zombies and Black Ops 3 Zombies.
Radio #1
Character: Maxis
The first radio in the Giant is located in the snowy section outside. Go to the left of the Pack-a-Punch Machine and you’ll find it tucked in a corner to the writing on the wall near the small stairway.
Radio #2
Character: Maxis
The second radio is located in the Animal Testing Facility. From the location of the first radio, go to the other side of the stairway in the middle and head inside the building to your right.
Once you head inside, you need to look for a filing cabinet tilted near the wall of the inner room with the broken window to the right of the door leading to Teleporter A. Search the bottom drawer of the filing cabinet to find the radio inside.
Radio #3
Character: Maxis
From the second location, head upstairs towards the bridge and you will find the third Giant radio in BO3 Zombies, under the sandbags just before the bridge leading to the second-floor generators
Radio #4
Character: Maxis
For the fourth radio, you need to head over to the backside of the platform near Teleporter C. Head over the stairs and you will find the radio sitting in a corner of the platform.
Radio #5
Character: Maxis
To find the fifth radio for Maxis, head over to the Furnace Room and you will find the radio between two pillars on the left side of the central furnace in the room.
Radio #6
Character: Nikolai Belinski or Maxis if played as Richtofen.
Go back to the location of the second radio, head inside the Z-1 room, and find the radio tucked neatly under the staircase leading up to Teleporter A.
Radio #7
Character: “Tank” Dempsey or Maxis if played as Richtofen.
For this radio, you need to go inside the Z-8 room within the Teleporter B room and check the left side of the central furnace to find it. You will find it hidden inside a toppled-over barrel. This particular radio can be especially hard to notice if you don’t know where exactly to look.
Radio #8
Character: Takeo Masaki or Maxis if played as Richtofen.
The final Giant radio is located to the left of the entrance to Dr. Maxis’ office, you need to head inside the area reading Z-C and turn right into the room with a broken wall. After you head inside, check the corner area with a broken floor covered by some planks
