It depends... I don't recall the scene. Was the only antenna the small one attached to the box itself, or was there one outside? And what was the antenna they used... did they just touch wires to the flag pole or do something else?
If the only antenna was inside the building, attached to the device... then between the strength / size / concrete-walls it might not have worked. But put the antenna outside, and high enough... then it might hit the mechs with a strong enough signal to interfere with their stuff.
Take your Wifi router or access-point, put it in your basement, and see how far outside you can get the signal.
Take the router or access-point, put it on your roof outside, and see how far you can get the signal now.
Edited on 08/16/2011 11:57am
Edited 2 total times.