Home Radio waves Japan’s only shortwave station still in operation after 80 years: The Asahi Shimbun

Japan’s only shortwave station still in operation after 80 years: The Asahi Shimbun



KOGA, Ibaraki Prefecture – Standing tall and proud over an area of ​​approximately 1 million square meters, a forest of red and white two-tone steel towers is the dominant feature under the blue sky with the backdrop of Mount Tsukubasan.

This is KDDI Corp.’s Yamata transmission station, the only facility in the country that broadcasts shortwave radio programs to foreign listeners.

The station began broadcasting on January 1, 1941. The main building still retains a pre-war vibe.

Shortwave radios were the primary means for people around the world to receive audio content from Japan without large-scale installation before the emergence of satellites and submarine cables.

The announcement of the surrender of Japan by Emperor Hirohito in 1945 was transmitted from here to military personnel on the battle fronts overseas.

A photo apparently taken during or after the war shows the main building of the Yamata transmission station. (Provided by KDDI Corp.)

When it was completed in 1940, Yamata, now part of Koga, was a typical farming village with a population of 4,536, 90 percent of whom were farmers, according to a 1941 local history brochure.

“A large area of ​​plain was available, and it was less prone to damage from snow and typhoons,” said Kazuhiro Matsui, 50, a senior infrastructure official who served as a guide when the resort was down. presented to media representatives in April. “I think it was the only place worthy of the resort in the country.”

The steel towers are arranged so that 18 transmitting antennas cover 360 degrees to send broadcasts as far north as Boston and London and as far west as Seoul and Nairobi.

The seven transmitters are installed with vacuum tubes, which have been used to amplify radio waves since the station’s operations began. Each tube weighs around 70 kilograms, according to Matsui.

The control room monitors transmitters and other broadcast facilities 24 hours a day, and workers switch between antennas every broadcast hour to ensure the facilities are functioning properly.

Shortwave refers to a range of radio signals from 3 to 30 MHz. The signals reach the most remote corners of the globe as they bounce between the surface of the Earth and the ionosphere which envelops the planet at a height of several hundred kilometers.

FM waves, whose frequency is higher than short waves, enter the ionosphere and can travel only about 100 km. AM waves, which have a lower frequency, are attenuated when refracted by the ionosphere or the earth’s surface, resulting in shorter travel distances than short waves.

Shortwave broadcasting was particularly popular in times of war.

Japan’s propaganda broadcasts in its colonies, as well as “The Zero Hour,” an English-language radio program aimed at demoralizing US troops in the South Pacific, were broadcast from here.

A photo apparently taken during wartime shows workers inside the Yamata transmission station. (Provided by KDDI Corp.)

According to Matsui and other sources, women were mobilized from surrounding areas and put in charge of radio transmission, maintenance and other services because engineers at the station were forced into military service to work as communications officers. .

“I heard that those who worked at the station during the war came back to see the cherry blossoms for the sake of the good old days,” Matsui said.

Despite the advent of satellite broadcasting and the Internet, shortwave radios still have an important role to play.

Yamata’s broadcast station broadcasts NHK’s World Radio Japan program.

Shortwave radios served as a source of information during the Persian Gulf War in 1990 for the Japanese stranded in the Middle East.

In 2007, the Commission of Inquiry on Missing Persons, a group investigating the kidnapping issue in North Korea, began broadcasting the Shiokaze shortwave radio program intended for North Korea from the broadcasting station. by Yamata.

“Shortwave can reach anywhere under any circumstance, and you don’t need full equipment to receive it,” Matsui said. “Their importance remains unchanged.