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"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, June 13, 2010

Early Mediumwave Stations in Japan

The early invention and development of wireless and radio in Japan ran parallel to the similar events that were taking place at the time in Europe and in the United States. It was in the year 1889, six years before Marconi, I might add, that the first wireless experiments took place in Japan. This first public demonstration of wireless, quite simple in its style, was given by Hantaro Nagaoka at the University of Tokyo.

Ten years later, the manufacture of wireless equipment began in Japan. Then, it was in the year 1902 that the Japanese navy established its first experimental wireless stations and these were installed at navy yards in Tokyo and Yokohama. It is understood that these two wireless stations were the first that were installed anywhere in Asia.

During the following year, 1903, the Annaka Electric Company demonstrated wireless transmission and reception at the 5th Japan Industry and Promotion Exposition by setting off a fireworks display. Then, in April 1925, Tokuji Hyakawa assembled a crystal set receiver and tuned in to the transmissions from his own transmitter.

Interestingly, the first Japanese radio broadcasting station was erected, not in Japan, but in China. This station was constructed in Japan using Japanese made equipment and it was installed at Shuang Chaio, some eight miles from Peking, or Beijing, as we know the city today. This mediumwave broadcasting station was inaugurated on June 29, 1924.

However, the first transmission of radio broadcast programs in Japan itself began on March 1, 1925, with a test broadcast from a temporary station located on Atago Hill in Tokyo. A photograph from that era shows that the Minister for Communications in the national government heard this broadcast. This first temporary radio broadcasting station was officially inaugurated three weeks later on March 22 with a program that included classical European and Japanese music.

Four months later, on July 12, 1925, a permanent radio broadcasting station for Tokyo was inaugurated at Atagoyama. The main 1 kW transmitter was made in the United States, though the reserve transmitter was locally assembled, by the staff at the radio station itself. At the time, there were just three thousand five hundred radio receivers in operation in the Tokyo area.

Similar stations were constructed around the same time in Osaka and Nagoya, and these were both officially opened during the same year 1925.

The callsigns and details for these three radio stations were:

JOAK Tokyo 1 kW 800 kHz
JOBK Osaka .5 kW 780 kHz
JOCK Nagoya 1.5 kW 833 kHz

The system of letters used for the callsigns in early radio stations in Japan is quite intriguing. We look at their first station, JOAK, for example.

The letter J obviously stood for Japan. Maybe the second letter, O, stood for Oceania, which was part of the callsign identification for radio stations in several countries in the Pacific arena in those days. The final letter K, we could guess, stood for Kyokai, a Japanese word that was later incorporated into the official name for the Japanese radio broadcasting service, NHK, Nippon Hoso Kyokai.

Interestingly, the third letter in their callsign system, indicated the chronological order in which the station was established. Thus JOAK was their first station, JOBK was their second, JOCK was their third, etc., and right on down through the English alphabet. By the mid 1930s, they used up the twenty six letters in the English alphabet and new callsigns were issued, this time ending in the letter G; and subsequently, many other letters also.

In the mid 1930s, more than thirty mediumwave stations were on the air throughout Japan and these stations were regularly heard in the United States, New Zealand and Australia. Several of the main stations in the large cities were by this time operating a second program channel under the same callsign with a number appended, for example:

Tokyo JOAK1 on 870 kHz and JOAK2 on 590 kHz
Osaka JOBK1 on 690 kHz and JOBK2 on 940 kHz
Nagoya JOCK1 on 730 kHz and JOCK2 on 990 kHz

In August 1936, many of the broadcasting stations in Japan took a live relay from Germany during the Berlin Olympics.

The radio stations in Japan have always been prolific verifiers of reception reports from listeners. Although there are several undated QSL cards from Japan in the Indianapolis QSL Collection, it is probable that the earliest is dated on May 31 in the year 1931 and it was from the key station in the NHK network, JOAK in Tokyo.

This QSL card shows that station JOAK was on the air by this time with a power of 10 kW. This card shows a small black and white photo of their studio and transmitter building. In red is a small ornamental picture, the size and shape of a postage stamp, and it is very reminiscent of the American EKKO QSL stamps from the same era.

Many of the QSL cards from Japan also show an artistic picture, or an actual photo, of the famous Mt. Fuji. Many cards also show photos of the radio broadcasting station, the building, the antenna towers, and the studio facilities. In addition, the QSL secretary in several stations actually copied the program details from the listener’s reception reports onto the QSL card.

Interestingly, one of these early Japanese QSL cards shows a short text in the international Esperanto language. This card was printed for use as a verification for station JOAK in Tokyo, but it was modified for usage by a small relay station, JOJK in Kanazawa, with 3 kW on 423 metres, 710 kHz. The text in the language Esperanto reads: Oni korespondas per Esperanto. Translated into understandable English, it reads: We correspond in Esperanto.