FM broadcasting in Japan
Encyclopedia
The frequency modulation
radio broadcast band in Japan
is 76-90 MHz. The 90-108 MHz section is used for television for VHF Channels 1,2 and 3. 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.
, 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.
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.
Frequency modulation
In telecommunications and signal processing, frequency modulation conveys information over a carrier wave by varying its instantaneous frequency. This contrasts with amplitude modulation, in which the amplitude of the carrier is varied while its frequency remains constant...
radio broadcast band in Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
is 76-90 MHz. The 90-108 MHz section is used for television for VHF Channels 1,2 and 3. 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.
Receiver issues
Many Japanese radios are designed to be capable of receiving both the Japanese FM band and the CCIR FM bandCCIR 601
ITU-R Recommendation BT.601, more commonly known by the abbreviations Rec. 601 or BT.601 is a standard published in 1982 by International Telecommunication Union - Radiocommunications sector for encoding interlaced analog video signals in digital video form...
, 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
Diode
In electronics, a diode is a type of two-terminal electronic component with a nonlinear current–voltage characteristic. A semiconductor diode, the most common type today, is a crystalline piece of semiconductor material connected to two electrical terminals...
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. Also, RDSRadio Data System
Radio Data System, or RDS, is a communications protocol standard for embedding small amounts of digital information in conventional FM radio broadcasts. RDS standardises several types of information transmitted, including time, station identification and programme information.Radio Broadcast Data...
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.