I suggest taking another look in the room you found the radio (the rightmost room on Floor 1)!
Same problem, I believe.
When trying to go to the right, there is a guard with 2 movable blocks in front of him. Because they are in the lower position, it's impossible to get past the guard. As I can no longer go into the tunnels, there are also no switches I can use to move the blocks up again (which would allow me to get past).
Also, weird bug. At the end of chapter one, I was standing in the area in front of the guard. I then left the device suspended for a couple of days. When I resumed, I could no longer move, but I could still turn, and could fire a bow and arrow (despite not having one...).