After following a beacon signal, Jack makes his way through an abandoned building, tracking the source. At one point he stops by a box on the wall, as he sees a couple of cables coming out from the inside of it, and cautiously opens it.
The repeater
I can’t talk much about interactions on this one given that he does not do much with it. But I guess readers might be interested to know about the actual prop used in the movie, so after zooming in on a screen capture and a bit of help from Google I found the actual radio.
When Jack opens the box he finds the repeater device inside. He realizes that it’s connected to the building structure, using it as an antenna, and over their audio connection asks Vika to decrypt the signal.
The desktop interface
Although this sequence centers around the transmission from the repeater, most of the interactions take place on Vika’s desktop interface. A modal window on the display shows her two slightly different waveforms that overlap one another. But it’s not clear at all why the display shows two signals instead of just one, let aside what the second signal means.
After Jack identifies it as a repeater and asks her to decrypt the signal, Vika touches a DECODE button on her screen. With a flourish of orange and white, the display changes to reveal a new panel of information, providing a LATITUDE INPUT and LONGITUDE INPUT, which eventually resolve to 41.146576 -73.975739. (Which, for the curious, resolves to Stelfer Trading Company in Fairfield, Connecticut here on Earth. Hi, M. Stelfer!) Vika says, “It’s a set of coordinates. Grid 17. It’s a goddamn homing beacon.”
At the control tower Vika was already tracking the signal through her desktop interface. As she hears Jack’s request, she presses the decrypt button at the top of the signal window to start the process.