Installing the Signal Repeater
The last objective is to install the signal repeater in the National Isolated Radio Array. Return to the Top of the World and from here go to the place marked in the picture above. You’ll get there without any problems because the radar is visible from a long distance.
Once you get there, find the antenna shown in the picture above. There will be a lot of aggressive robots in the area and one Super Mutant in the blue post. Get rid of all the opponents first to make the task easier. Go to the antenna and use the interaction button – you’ll install the signal repeater. After that be ready to fight the robots. If the number of enemies overwhelms you, use grenades or Molotov cocktails. It is also worth hiding behind the antenna to avoid being shot.
You’ll need to power the installed signal repeater. To do this, go to the blue post where you’ve killed the Super Mutant, use the computer and choose the power redirection option.
Completing the quest
Lastly, you have to speak to Rose. Return to the Top of the World and use the elevator (this time you’ll be able to reach the last floor). Leave the elevator and go to the next room on the left and in the meantime loot all the corpses (you can find a few grenades). You’ll reach a room with Rose and Madigan’s corpse (which was a part of The Missing Link quest). Talk to Rose to end the Signal Strength mission – as a reward, you’ll get: medicaments, water, ammo, crafting schematics and caps.
Use the interaction button on the Madigan’s corpse to update The Missing Link quest. You’ll find out that Rose can share Madigan’s knowledge with you if you do two task for her. Speak with her and you’ll get the next main story mission – Flavors of Mayhem.