[Game lore] Source of the signals

Tuesday. Already 13th. Still 1994. The signals dont come from anything that is alive. Atleast not in our idea of being alive. Its a specific signal only robots can output. Its moving, not standing in one place. Ive hidden the signal receiver away from the Eight, its the only technology they havent found yet and the other bunker guys arent snitching on me either, i guess they understand the situation and consider me as one of them already. But yeah, the signal. Yesterday it was farther away. It kept coming closer but stopped last night and hasnt gone closer. Did something happen to it? Did one of the irradiated beasts catch it? Wait a second.... the signal. Its gone. What the hell? It cant be my signal receiver malfunctioning, i just fixed it last week with brand new parts i smuggled in through an undercover trader hiding as a member of the Eight. The damn signal - where did it go? I just heard it a minute ago. Did the robot explore? Or... did it get eaten by something bigger?