The Radio Tower is guarded by a few Infected Military.
- Open the Radio Tower fence door with the Radio Tower Fence Key which can be found in the Cave below the Radio Tower if lucky or guaranteed in Zone 2 Sewers.
- Repair the Radio Tower generator by inserting an Air Filter, an Alternator, 4 Spark Plug, a Fuel Hose and 3 Fuel Filter in the generator inventory, click the Repair button, and switch the generator on.
- The generator will power the radio in the center room.
- Open the center room door with the Radio Tower Key (found in the warehouse in front of the Sewers entrance).
- Repair the radio by adding an Electronic Board, 4 Electric Wire and 10 Scrap Metal in the radio inventory and press the "repair" button.
- You will hear a metallic sound as the safe unlocks.
- Open the Safe and take the Dungeon Key Compts List book.
- Read the book to learn the Dungeon Key Level 1 recipe.
Dungeon Key Level 1 recipe