"Wavescan" is a weekly program for long distance radio hobbyists produced by Dr. Adrian M. Peterson, Coordinator of International Relations for Adventist World Radio. AWR carries the program over many of its stations (including shortwave). Adrian Peterson is a highly regarded DXer and radio historian, and often includes features on radio history in his program. We are reproducing those features below, with Dr. Peterson's permission and assistance.
Wavescan N365, February 21, 2016
The Beginning of the New Shortwave Era on the Island of Guam
Back in December 1941, all of the wireless and radio stations on the island of Guam were either badly damaged or totally destroyed at the time of the Japanese invasion and occupation of the island. The large and important American naval radio station NPN at Nimitz Hill was destroyed in a Japanese air raid during the initial attacks on December 10.
During the nearly three years of Japanese occupation, there was almost no American radio activity on the island, though there were a few occasional clandestine transmissions. The Japanese occupation forces installed their own temporary radio communication facility, which we presume was somewhere within the areas of the island capital Agana. This station was also destroyed by aerial activity when the American forces made a bombing raid on July 16, 1944; and they secured the island a little less than a month later, on August 10.
American radio communications were provided initially by the USS Appalachian at anchor in Agat Harbor, quite near the coastal area whereon the AWR shortwave station KSDA is now located. The Appalachian, under the regular navy callsign NCLG, arrived in Agat Harbor on July 14 (1944) and they maintained sector communications until they departed for Pearl Harbor on August 10, a period of nearly one month.
Apparently another ship in Agat Harbor took over the communication role until a temporary land based station was installed somewhere in the Agat area. This new station was first noted in the United States on 15260 kHz under the callsign NPN8, just after mid September (1944).
In the meantime, reconstruction was underway for a permanent facility, with station control in the naval headquarters on Nimitz Hill, the transmitters at Barrigada, and the receiver station at Finegayan. A total of 91 shortwave channels were allocated for use by the new naval station NPN, and the callsign K2XO was introduced for communication with other Allied centers throughout the Pacific.
In March 1945, this new naval radio station was inaugurated for regular usage, and it went on the air under the tactical callsign KU5Q. At this stage, three transmitters were in use, each rather low powered, with at least one rated at 2 kW. However, propagation to Asia, the South Pacific and the United States mainland was usually very good, due to the extended saltwater pathway across the Pacific Ocean.
For a year or so, the Finegayan receiver station was also in use for the monitoring of Japanese radio traffic in the Pacific. A radio analysis group was formed and they operated under a temporary callsign NIM.
The new KU5Q was often noted in Morse and voice communication with Asia, the Philippines, California, Hawaii and other islands throughout the Pacific, as well as with naval and commercial shipping in nearby waters. On many occasions, the station also relayed radio programs for onward broadcast to and from Pacific rim countries, programs that included news bulletins and commentaries, sports, and local music programs.
There were occasions also when KU5Q was noted in Australia, New Zealand and the United States with a relay of the programing from the AFRS mediumwave station WXLI. The studios for both KU5Q and WXLI were co-located at Mt. Alutom, a few miles southwest of Agana.
In March 1945, KU5Q relayed live commentaries from a navy vessel during the American invasion of Okinawa for rebroadcast in the United States. Then in September 1945, KU5Q played a key role in the relay of news and information to and from the United States for the Peace Ceremony and the signing of the peace documents in Tokyo Bay.
At this stage, it was officially announced that the international communication services rendered by KU5Q on Guam, and hence the usage of the callsign KU5Q, would cease at the end of the month of October. However, the usage of the KU5Q international relay service was extended for exactly one more year.
In July 1946, KU5Q served as a co-ordinating relay for radio communication with navy vessels associated with Operation Crossroads, the American atomic tests over Bikini Atoll. At this stage, KU5Q operated with six transmitters, five at 3 kW and one at 10 kW, a TEC model manufactured by Press Wireless.
There were many occasions when KU5Q was on the air with four transmitters in parallel. The antenna systems were unidirectional rhombics, 860 feet long.
During the final month or two of service under the callsign KU5Q, the station was under the control of the naval Public Information Service. QSL cards and form letters were issued, and the greatest quantity of reports, they stated, came from Sweden.
The usage of the tactical callsign KU5Q ended in 1946, though this naval radio station continued in regular communication service under the original naval callsign NPN. The station was rebuilt in 1954, with a new receiver station adjacent to the older station at Finegayan, and a new transmitter station at Barrigada.
The American naval radio station NPN on the island of Guam has also issued QSL cards for its communication transmissions with the callsign NPN in large letters superimposed over a map of the island of Guam.