USN had an interesting device for assisting aircraft back to the carrier, the YE antenna. This transmitted a directional signal, with a different morse code letter for each 15 deg sector. Prior to the mission pilots were issued a code table for the day with the letters for each sector. Receiving the coded letter, one knew what sector the aircraft was from the carrier. At several thousand feet reception was possible out to 40 NM. The antenna was dubbed the "Hay Rake".