 Metox sets received the transmitted pulses from the ASV and rendered them as audible beeps.It enjoyed the usual advantage of radar detectors over radar in that the signal is direct and only had to travel one way whereas the radar has to detect the very weak reflection from the submarine.Most radars increase the number of pulses and decrease the width of the pulses when switched to a shorter range, the shorter pulse widths allow the radar to look at closer objects.