FM broadcasting in Japan
|This article does not cite any references or sources. (November 2006)|
The frequency modulation radio broadcast band in Japan is 76-90 MHz. The 90-108 MHz section was used for television for VHF channels 1, 2 and 3 until the analog shutdown occurred on July 24, 2011. The narrowness of the Japanese band (14 MHz compared to slightly more than 20 MHz for the CCIR band) limits the number of FM stations that can be accommodated on the dial.
Many Japanese radios are designed to be capable of receiving both the Japanese FM band and the CCIR FM band, so that the same model can be sold within Japan or exported. The radio may cover 76 to 108 MHz, the frequency coverage may be selectable by the user, or during assembly the radio may be set to operate on one band by means of a specially-placed diode or other internal component.
Conventional analog-tuned (dial & pointer) radios may be marked with "TV Sound" in the 90-108 section. If these radios were sold in the USA, for example, the 76-88 section would be marked TV sound for VHF channels 5 and 6, with the 88-108 section band as audio FM.
Used automobile resale issues
Second-hand automobiles imported from Japan contain a radio designed for the Japanese FM band, and importers often fit a "converter" to down-convert the 87.5 to 107.9 MHz band to the frequencies that the radio can accept. In addition to showing an incorrect frequency, there are two other disadvantages that can result in undesired performance; the converter cannot downconvert in full the regular international FM band (up to 20.5 MHz wide) to the only 14MHz wide Japanese band (unless the converter incorporates two user-switchable downconvert modes), and the original antenna may perform poorly on the higher FM band. Another problem is that RDS is not used in Japan, whereas most modern car radios available in Europe avail of this system. Also the converter may not allow pass-through of the MW band (if desired). A better solution is to replace the radio and antenna with ones designed for the country where the car will be used, but this can be difficult where custom-built radios are fitted.