Vol.22 Historic Site on Tama Campus, Hosei University Site of "Tama Transmitting Station" which announced Japan's acceptance of the Potsdam Declaration to the world

On the Tama Campus, a monument to the "Tama Transmitting Station Site" stands on the left before the uphill slope leading from the Egg Dome, through the Hosei Tunnel, to the Faculty of Sports and Health Studies building.
At the end of World War II, the military selected two locations for communication facilities to ensure overseas broadcasting and telegraphic communication in case of air raids on the mainland, and requested International Telecommunications Corporation (now KDDI) to build them. Ashigara Transmitting Station was established in 1944 as a bulletproof transmitting station. Another site was selected in the mountain forest between Aihara, Sakai-mura and Terada, Yokoyama-mura in Minamitama-gun, Tokyo, behind the monument mentioned above and surrounded by ridges on three sides. In April 1945, the Tama Transmitting Station was established as a concealed transmitting station, taking advantage of the undulations and forests.

The Tama transmitting station transmitted overseas broadcasts and other broadcasts from antennas supported by cylindrical aerials on 60-meter-high wooden poles erected between trees covering an area of approximately 24 hectares. The equipment, however, was not state-of-the-art, but rather a relocation of equipment from other transmitting stations, and the rotating antenna was operated manually according to the direction of transmission. A dedicated communication antenna with Germany, an ally of the Allies, was also installed, but was not used after Germany surrendered to the Allies in May of 1945. The site was dotted with buildings where a total of 50 engineers and staff worked, and all the buildings were painted in camouflage.

At that time, Japan's external communications, other than those related to the government, included Morse telegrams from allied news agencies, and "overseas broadcasting" and "East-Asian relay broadcasting" broadcast by the Japan Broadcasting Corporation in various foreign languages. These foreign broadcasts, including the Tama Transmitting Station, played a historic role in transmitting the Japanese government's acceptance of the Potsdam Declaration to the entire world from August 10 to 15, 1945, the day after the atomic bomb was dropped on Nagasaki, independently of government diplomatic channels.

Overseas broadcasting ended with the end of the war on August 15, and the Tama Transmitting Station was closed in the fall of the following year, 1946. Since 1964, TUMSAT has purchased the forest that includes the site of the former transmitter station several times, and with the opening of the Tama Campus, excavation surveys of the area were conducted in the 1970s and 1980s. The remains of the Tama Transmitting Station were confirmed, and in March 1988, a monument was erected to "record the history of the station and hand it down to future generations for many years to come. The stone used for the base of the pillar remains beside the monument, conveying the image of those days.