No. 1 Wireless Unit RAAF was an Australian signals intelligence unit of World War II. The Unit was established on 25 April 1942. This name which was the formalised name given to the small RAAF Intercept Station operating in two back-to-back houses at 21 Sycamore Street and 24 French Street in the suburb of Pimlico in Townsville established by Wing Commander Booth in March 1942. 1 Wireless unit became part of the larger Central Bureau established under Macarthur and comprised 7 RAAF, 1 AMF and 4 United States Army personnel in No. 1 Wireless Unit at Townsville. Flight Lieutenant Blakely was the first Commanding Officer. He was assisted by Captain H. Brown, US Army, and four US Air Force sergeants who were experienced in Sigint and who had escaped to Australia from the Philippines. History The first seven RAAF personnel to be trained as part of No. 1 Wireless Unit in a "special intelligence" course were trained at Victoria Barracks in Melbourne in July 1941. They were the first personnel in No. 1 Wireless Unit which was to be involved in the interception of Japanese Naval and military traffic. They were all qualified radio operators and extremely proficient in international Morse code. The six members of the unit who completed training were sent to Darwin. They set up two intercept radios (Kingsley AR7's on the top floor of the "Camera Obscura" building at the RAAF Darwin airfield. They worked in continuous 4-hour shifts intercepting Japanese naval "point to point" and "aircraft to ground" traffic from Japanese at the following locations:- Palau Saipan (Marianas) Tokyo Truk (Caroline Islands) Their intercepts were sent to the navy cryptology section in Melbourne via RAAF Signals Darwin. They enciphered their messages to Melbourne in a secret cipher before passing them over to the RAAF Signals personnel. This ensured that their intercepts of Japanese Kana code or encoded messages were not apparent to other military personnel to protect the secrecy of their intercept operation. In the meantime, the RAAF began to establish their own small administrative and intelligence group in Melbourne. H. Roy Booth was in charge of this new group. Their task was to start to learn how to process the intercept information sent from Darwin. The RAAF Kana operators in Darwin intercepted many important transmissions leading up to the attack on Pearl Harbor. The Darwin intercept group was reduced to four due to illness.