Standard time and frequency signals are transmitted at high-precision standard frequencies in the long-wave band, and in addition to being used for maintenance and improvement of the frequency precision of waves emitted by radio stations, have the future potential to help achieve denser frequency allocations using such high-precision frequencies as benchmarks.
For this reason, the Ministry of Internal Affairs and Communications (MIC) maintains standard time and frequency signal equipment and employs standard time and frequency signals to provide radio stations, etc. with high-precision frequencies.
In line with the duties of the MIC as stipulated in the Ministry of Internal Affairs and Communications Establishment Act, which include setting standard frequency values, emitting standard time and time and frequency signals, and providing standard time signals, the MIC delegates the following duties related to ĀgProviding Radio Stations with High-Precision Frequencies Through Standard Time and frequency signalsĀh to the National Institute of Information and Communications Technology (NICT).
(1) Calibration of radio station frequencies
By continuously supplying radio stations with high-precision frequency standards using standard time and frequency signals, the project enables automation of radio station frequency calibration, contributing to the convenience of licensed radio broadcasters.
(2) Synchronization of radio station frequencies
Enables the highly precise synchronization required by radio stations and base station for mobile radio broadcasters, facilitating faster initial synchronization between radio stations and more efficient use of frequencies.
|Table: Specifications for standard time and frequency signal broadcaster (JJY)|
|Sites||Haganeyama Transmitter Fuji-cho, Saga City, Saga Pref.||Otakadoyayama Transmitter (Miyakoji-machi, Tamura City, Fukushima Pref.)|
|Latitude / Longitude||33°28ĀĆN 130°11ĀĆĀćE||37°22ĀĆN 140°51ĀĆE|
|Antenna power||50kW (Effective radiated power: 10kW or more)|
|Antenna type||Umbrella type, 200m elevation||Umbrella type, 250m elevation|
|Radio wave type||A1B|
|Standard frequency||Carrier wave: 60kHzĀ@Modulated wave: 1Hz Amplitude of modulated wave: Max. 100%, Min. 10% * (Except when transmitting call sign) Amplitude 0 - 100% when transmitting call sign||Carrier wave: 40kHzĀ@Modulated wave: 1Hz Amplitude of modulated wave: Max. 100%, Min. 10% * (Except when transmitting call sign) Amplitude 0 - 100% when transmitting call sign|
|Accuracy of frequency and time signal intervals||±āP×āPāO-12|
|Start date||October 1, 2001||June 10, 1999|