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Supplying Radio Stations with High-Precision Frequencies

1.Purpose of the Project

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.

2.Outline of the Project

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 "Providing Radio Stations with High-Precision Frequencies Through Standard Time and frequency signals" 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°28′N 130°11′″E 37°22′N 140°51′E
Antenna power 50kW (Effective radiated power: 10kW or more)
Antenna type Umbrella type, 200m elevation Umbrella type, 250m elevation
Radio wave type A1B
Operation Continuous
Standard frequency Carrier wave: 60kHz 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: 40kHz 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 ±1×10-12
Start date October 1, 2001 June 10, 1999
Division in Charge:Land Mobile Communications Division