Radar detectors are a passive device. They do not emit a signal , only detects a radar signal that hits them. The radar detector in the game works well. It has saved my bacon on several encounters with ships and planes. HOWEVER the radar that you can get is nothing more than a homing beacon. Plus it is almost useless. If I'm not mistaken it only had a 40 degree arc on each side. In order to do a full 360 degree sweep, the u-boat had to go in a circle. what a waste.
