Activate Radio Towers to reveal Inhibitor locations in the Zones. You must first get the GRE Detector, which will happen in the quest "Broadcast". After activating a Radio Tower, all Inhibitor containers hidden within the Zones covered by the tower's signal will be marked on your map (max zoom in).
Radio Towers
Locations on Old Villedor
1
Saint Joseph Medical Radio Relay
Show the map
Locations on Central Loop
2Broadcast Antena
Show the map
3Historical Communications Tower (3)
Show the map
4Newfound Land Military Relay (6)
Show the map
5North Loop Radio Tower (3)
Grappling Hook required.