The FM band in Japan is 76–90 MHz. The 90–108 MHz section was used for analog VHF TV Channels 1, 2 and 3 (each NTSC television channel was 6 MHz wide). 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 with the result that many commercial radio stations are forced to use AM. However, as the NTSC channels cease analog operations, it is possible that the CCIR FM band might expand to Japan.
Many Japanese radios are 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 (as two 6 MHz-wide NTSC TV channels), with the 88–108 section band as normal FM.

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 14 MHz-wide Japanese band (unless the converter incorporates two user-switchable downconvert modes), and the car's antenna may perform poorly on the higher FM band. Some converters simply down-convert the FM band by 12 MHz, leading to logical frequencies (e.g. 78.9 for 90.9, 82.3 for 94.3, etc.), but leaving off the 102–108 MHz band. Also, RDS is not used in Japan, whereas most modern car radios available in Europe have this system. Also the converter may not allow pass-through of the MW band, which is used for AM broadcasting. A better solution is to replace the radio and antenna with ones designed for the country where the car will be used.

Australia had a similar situation with Australian TV channels 3, 4 and 5 that are between 88 and 108 MHz, and was intending to follow Japan, but in the end opted for the western bandplan, due to CCIR radios that entered the country. There were some radios sold in Australia for 76 to 90 MHz.

Prev:WDIY triples signal strength

Next:How to Convert WMV to H.264

Leave a message

Message List

Comments Loading...

Products Category

Products Tags

Fmuser Sites

What is Japanese bandplan

Leave a message

Message List