Opana Radar Site

In December 1939, the U.S. military established an Aircraft Warning Service (AWS) using radar to defend American territory. It employed the SCR-270 radar, the first United States long-range search radar created at the Signal Corps laboratories at Fort Monmouth, New Jersey, circa 1937. The radar's operating frequency was 106 megahertz and it had a maximum range of 150 miles, or greater if the equipment was at an elevated site. Under the command of Col. Wilfred H. Tetley the AWS established six mobile radar detector sites on O'ahu at Kawaiola, Wainaae, Kaʻaʻawa, Koko Head, Schofield Barracks, and Fort Shafter. On Thanksgiving Day in 1941, the Schofield Barracks radar set was moved to the Opana Radar Site, a location 532 feet above sea level with an unobstructed view of the Pacific Ocean. The set comprised four trucks carrying the transmitter, modulator, water cooler, receiver, oscilloscope, operator, generator and antenna. ==Attack on Pearl Harbor==

On December 7, 1941, the Opana Radar Site was manned by Private Joseph Lockard and Private George Elliot, who detected approaching aircraft at 7:02 am (past the end of the site's scheduled operating day). Since the truck to take them to breakfast was late, the pair continued to practice with the radar equipment. Tyler reasoned that the activity was a flight of Army B-17 Flying Fortress bombers, and advised the radar crew not to worry. Tyler told investigators that a friend in the Bomber group advised him that whenever the radio station played Hawaiian music all night, a flight from the mainland was arriving, and using that for navigation homing. McDonald was relieved at about 7:40 and returned to his tent waking his tent mate up by saying "Shim the Japs are coming". Elliot and Lockard continued plotting the incoming planes until 7:40 when contact was lost. Shortly before 8:00 am they headed to Kawailoa for breakfast and only learned about the attack when they arrived. Elliot and Lockard rushed back to Opana and operated the radar until the attack ended. ==Today==

Today, a modern Navy telecommunications station occupies the top of the Opana Hill adjacent to the site. The station is a relay for the Department of State's Diplomatic Telecommunications Service. The former site is a National Historic Landmark and IEEE Milestone. Since the 1941 radar was a mobile unit, there is no physical evidence of the historic unit at the site. There is a commemorative plaque on the grounds of the Turtle Bay Resort at the foot of Opana Hill. ==See also==